Determining the strength of non-destructive testing mechanical methods. Determination of the strength of mechanical methods of non-destructive testing E.5 Terms of use of calibration dependence

The goals, the basic principles and the main procedure for carrying out work on interstate standardization are GOST 1.0-92 "Interstate standardization system. Basic provisions "and GOST 1.2-2009" Interstate standardization system. Standards interstate, rules and recommendations on interstate standardization. Rules for the development, adoption, applications, updates and cancellations »

1 Developed by the structural division of the NIC Construction JSC, the research, design and design and technological institution of concrete and reinforced concrete. A.A. Nail (niizb)

2 Submitted by the Technical Committee on Standardization TC 465 "Construction"

3 Adopted by the Interstate Council for Standardization, Metrology and Certification (Protocol of June 18, 2015 No. 47)

Short name of the country on MK (ISO 3166) 004-97	Country code on MK (ISO 3166) 004-97	Abbreviated name of the National Authority By standardization
Armenia		Ministry of Economy of the Republic of Armenia
Belarus		Gosstandart of the Republic of Belarus
Kazakhstan		Gosstandart of the Republic of Kazakhstan
Kyrgyzstan		Kyrgyzstandart
Moldova		Moldova Standard
Russia		Rosstandard.
Tajikistan		Tajikstandard

4 orders Federal Agency on technical regulation and metrology of September 25, 2015 No. 1378-ST Interstate standard GOST 22690-2015 was introduced as the National Standard of the Russian Federation from April 1, 2016

5 In this standard, the main regulations in part of the requirements for mechanical methods of non-destructive testing of concrete strength of the following European regional standards are taken into account.

EN 12504-2: 2001 Testing Concrete In Structures - Part2: Non-Destructive Testing - Determination of Rebound Number (Concrete Test in Constructions. Part 2. Non-destructive testing. Definition of the criterion of the rebound);

EN 12504-3: 2005 Testing Concrete in Structures - Determination of Pull-Outforce (Concrete Test in Designs. Part 3. Determination of the Effort of Ottw).

The degree of conformity is non-equivalent (NEQ)

Information about the changes to this standard is published in the annual information indicator "National Standards", and the text of the amendments and amendments - in the monthly information indicator "National Standards". In case of revision (replacement) or the cancellation of this Standard, the appropriate notification will be published in the National Standards Monthly Information Index. Relevant information, notification and texts are also posted in the public information system - on the official website of the Federal Agency for Technical Regulation and Metrology on the Internet

GOST 22690-2015

Concretes.
Determination Of Strength by Mechanical Methods of NondestRUCTIVE Testing

Date of administration - 2016-04-01

1 area of \u200b\u200buse

This standard applies to structural heavy, fine-grained, lightweight and strain concrete concrete, precast and collection-monolithic concrete and reinforced concrete products, structures and structures (hereinafter - designs) and establishes mechanical methods for determining concrete compression strength in structures for elastic rebound, impact pulse , plastic deformation, separation, rolling ribs and leaving with rocking.

2 Regulatory references

This standard uses regulatory references to the following interstate standards:

Note - Standard test diagrams are applicable in a limited range of concrete strength (see applications. and ). For cases that do not relate to standard test diagrams, there should be calibration dependencies in general rules.

4.6 The test method should be selected based on the data given in the table, and additional restrictions set by the manufacturers of specific measurement tools. The use of methods outside the concrete strength recommended in the table is allowed under scientific and technical substantiation according to the results of studies using measurement tools that have passed the metrological certification for the extended range of concrete strength.

Table 1

Name method	Limit values \u200b\u200bof concrete strength, MPa
Elastic rebound and plastic deformation	5 - 50
Impact impulse	5 - 150
Foundation	5 - 60
Rubbing ribs	10 - 70
Running with a rocky	5 - 100

4.7 Determination of the strength of heavy concrete C60 design classes and higher or at the average strength of concrete concrete R M. ≥ 70 MPa in monolithic structures It is necessary to carry out the provisions of GOST 31914.

4.8 Concrete strength is determined in areas of structures that do not have visible damage (detachment of the protective layer, cracks, cavities, etc.).

4.9 The age of concrete controlled structures and its sites should not differ from the age of concrete structures (sites, samples) tested to establish graduation dependency, more than 25%. Exceptions are controlling the strength and construction of calibration for concrete, which exceeds two months. In this case, the difference in age separate designs (plots, samples) is not regulated.

4.10 Tests are carried out at a positive temperature of concrete. It is allowed to conduct tests when negative temperature Concrete, but not lower than minus 10 ° C, when establishing or binding a graduation dependence, taking into account the requirements. The temperature of the concrete during testing should correspond to the temperature provided for by the operating conditions of the instruments.

The calibration dependences mounted at a concrete temperature below 0 ° C are not allowed to be used at positive temperatures.

4.11 If necessary, testing concrete constructs after thermal treatment at surface temperature T. ≥ 40 ° С (for controlling the release, geduction and platform of concrete), the calibration addiction is set after determining the strength of concrete in the design by an indirect non-destructive method at a temperature at temperatures t. = (T. ± 10) ° C, and concrete testing by direct non-destructive method or sample tests - after cooling at normal temperature.

5 Measurement Means, Equipment and Tool

5.1 Measurement tools and mechanical test devices designed to determine the strength of concrete must be certified and attacked in installed manner and must comply with the requirements of the application.

5.2 Indications of devices graded in units of concrete strength should be considered as an indirect indicator of concrete strength. These devices should be used only after establishing the calibration dependency "The instrument's reading is the strength of concrete" or binding the dependence installed in the device in accordance with.

5.3 The tool for measuring the diameter of the prints (caliper according to GOST 166), used for the method of plastic deformations, should ensure measurement with an error of not more than 0.1 mm, tool for measuring the depth of the imprint (the indicator of the hourly type according to GOST 577, etc.) - with the error Not more than 0.01 mm.

5.4 Standard Test Schemes for the separation method with Raning and Skola edges include the use of anchor devices and captures in accordance with the applications and.

5.5 For the separation method with the crewing, the anchor devices should be used, the depth of the sealing of which should be at least the maximum size of the large-scale concrete aggregate of the test design.

5.6 For the separation method, you should use steel discs with a diameter of at least 40 mm, a thickness of at least 6 mm and at least 0.1 diameters, with the roughness parameters of the glued surface at least RA. \u003d 20 microns according to GOST 2789. The glue for the cutting of the disk must provide adhesion strength with concrete at which the destruction occurs through concrete.

6 Test preparation

6.1.1 Preparation for testing includes verification of used devices in accordance with the instructions for their operation and the establishment of calibration dependences between the strength of concrete and the indirect characteristic of the strength.

6.1.2 Graduation dependence is established on the basis of the following data:

The results of parallel tests of the same stations of structures by one of the indirect methods and a direct non-destructive method for determining concrete strength;

Test results of construction sites by one of the indirect non-destructive methods for determining the strength of concrete and testing samples - cores selected from the same construction sites and tested in accordance with GOST 28570;

Test results of standard concrete samples by one of the indirect non-destructive methods for determining concrete strength and mechanical tests according to GOST 10180.

6.1.3 For indirect non-destructive methods for determining the strength of the concrete, the calibration dependence is set for each type of normalized strength specified in the concrete of one nominal composition.

It is allowed to build one graduation dependence for the concrete of one type with one type of large aggregate, with a single production technology, differing from the nominal composition and the value of the normalized strength subject to the requirements.

6.1.4 The permissible difference between the age of concrete of individual structures (sections, samples) When setting a calibration dependence on the age of concrete of the controlled design, adopted by software.

6.1.5 For direct non-destructive methods of software, it is allowed to use the dependences given in applications and for all types of normalized concrete strength.

6.1.6 Graduation dependence should have a rms (residual) deviation S T. H. M, not exceeding 15% of the average of the strength of the concrete of sections or samples used in constructing, and the coefficient (index) of the correlation is not less than 0.7.

It is recommended to use a linear dependence of the type. R. = a. + bk. (Where R. - Concrete strength, K. - indirect indicator). Method of establishing, evaluating parameters and determining the conditions for applying a linear graduation dependence is provided in the application.

6.1.7 When constructing a calibration dependence of the deviation of single concrete strength values R I. F from the average value of the strength of the concrete of sections or samples used to construct calibration dependence, should be within:

From 0.5 to 1.5 medium concrete strength at ≤ 20 MPa;

From 0.6 to 1.4 average concrete strength at 20 MPa< ≤ 50 МПа;

From 0.7 to 1.3 average concrete strength at 50 MPa< ≤ 80 МПа;

From 0.8 to 1.2 average concrete strength at\u003e 80 MPa.

6.1.8 The adjustment of the established dependence for concrete in the intermediate and project age should be carried out at least once a month, taking into account the addition of the results obtained. The number of samples or sections of additional tests during the adjustment must be at least three. The adjustment method is shown in the application.

6.1.9 It is allowed to apply indirect non-destructive methods for determining concrete strength, using calibration dependences mounted for concrete, differing from the tested in composition, age, experimental conditions, humidity, with reference in accordance with the method on the application.

6.1.10 Without binding to specific conditions by application, the calibration dependences set for concrete, differing from the subject, is allowed to be used only to obtain approximate values \u200b\u200bof strength. It is not allowed to use indicative strength values \u200b\u200bwithout reference to specific conditions for assessing the concrete class by strength.

Then select the areas in the amount provided for which the maximum, minimum and intermediate values \u200b\u200bof the indirect indicator are obtained.

After testing by an indirect non-destructive method, the plots are tested by a direct non-destructive method or select samples for the test according to GOST 28570.

6.2.4 To determine the strength at the negative temperature of the concrete, the sections selected for constructing or binding calibration dependents are first tested by an indirect non-destructive method, and then select samples for the subsequent test at a positive temperature or heated. external sources heat (infrared emitters, heat guns et al.) At a depth of 50 mm to a temperature not lower than 0 ° C and experience a direct non-destructive method. Monitoring the temperature of he warmed concrete is carried out at the depth of the installation of anchor device in the prepared hole or on the surface of the unit, a contactless manner with a pyrometer according to GOST 28243.

The rejection of test results used to construct calibration dependences at a negative temperature is allowed only if deviations are associated with a violation of the test procedure. In this case, the rejected result should be replaced by the results of the re-test in the same design zone.

6.3.1 When constructing a calibration dependence on control samples, the dependence is established by isolated values \u200b\u200bof the indirect indicator and strength of the concrete of standard sample cubes.

For the isolated value of the indirect indicator, the average value of indirect indicators for a series of samples or for a single sample is taken (if the calibration addiction is installed in separate samples). For the unit value of concrete strength, concrete strength in the GOST 10180 series or one sample (graduation dependence on separate samples) takes. Mechanical tests Samples according to GOST 10180 are carried out immediately after testing by an indirect non-destructive method.

6.3.2 When building a calibration dependence on the results of test samples, at least 15 episodes of sample cubes according to GOST 10180 or at least 30 separate cubic samples are used. Samples are manufactured in accordance with the requirements of GOST 10180 in different shifts, for at least 3 days from the concrete of one nominal composition, on the same technology, with the same hardening mode as the design to be controlled.

The unit values \u200b\u200bof the strength of the concrete of sample cubes used to construct calibration dependences should correspond to the expectations on the production of deviations, and be within the ranges set by B.

6.3.3 Graduation dependence For methods of elastic rebound, shock pulse, plastic deformation, separation and rolling edges, based on the test results of the manufactured sample cubes, first the non-destructive method, and then the destructive method according to GOST 10180.

When establishing calibration dependencies, the main and control samples of software are manufactured for the separation of the dumping. On the main samples, the indirect characteristic is determined, the control samples are tested according to GOST 10180. Basic and control samples must be made of one concrete and hardening at the same conditions.

6.3.4 Sample sizes should be selected in accordance with the greatest size of the aggregate in concrete mix According to GOST 10180, but not less:

100 × 100 × 100 mm for the methods of rebound, shock pulse, plastic deformation, as well as for the separation method with the rocking (control samples);

200 × 200 × 200 mm for the rib ribs of the design;

300 × 300 × 300 mm, but with the size of the edge of at least six depth of the installation of an anchor device for the rolling separation method (main samples).

6.3.5 To determine the indirect characteristics of strength, tests are carried out according to the requirements of the side (in the direction of concreting) edges of the sample cubes.

Total number Measurements on each sample for the method of elastic rebound, an impact pulse, plastic deformation during the strike should be at least the number of tests on the site on the table, and the distance between the shock sites is at least 30 mm (15 mm for the impact pulse method). For the method of plastic deformation under induction, the number of tests on each face should be at least two, and the distance between the test sites is at least two diameters of the prints.

When establishing a calibration dependence for the rib method, the ribs are carried out by one test on each side edge.

When establishing a calibration dependence for the rolling separation method, one tests on each side face of the main sample is carried out.

6.3.6 when testing the method elastic rebound, impact pulse, plastic deformation When hitting samples should be clamped in a press with an effort of at least (30 ± 5) kN and no more than 10% of the expected value of the destructive load.

6.3.7 Samples tested by the separation method are installed on the press so that the pressing plates of the press did not fit the surfaces on which the disconse. Test results according to GOST 10180 increase by 5%.

7 Testing

7.1.1 The number and location of controlled areas in constructions must comply with the requirements of GOST 18105 and specify in design documentation on the design or set aside:

Control objectives (determination of the actual class of concrete, platform or vacation strength, detecting sections of reduced strength, etc.);

Type of design (columns, beams, stoves, etc.);

Placement of the capture and order of concreting;

Reinforcement designs.

The rules for appointing the number of test sections of monolithic and prefabricated structures during concrete strength are shown in the application. When determining the strength of the concrete of the examined structures, the number and location of the sites should be made under the survey program.

7.1.2 Tests are carried out on a section of a construction area from 100 to 900 cm 2.

7.1.3 Total number of measurements on each site, the distance between the measurement sites on the site and from the edge of the structure, the thickness of the structures on the measurement portion should be at least the values \u200b\u200bgiven in the table depending on the test method.

Table 2 - T Adjusts to Test Points

Name method	Total number Measurements Location on	Minimum distance between In places of measurement on the plot, mm	Minimum Distance from edge Designs to place Measurements, mm	Mining thickness Designs, mm.
Elastic rebound
Impact impulse
Plastic deformation
Rubbing ribs
Foundation		2 diameters disk
Targeting with the creation of anchor sealingh.:
≥ 40mm
< 40мм

7.1.4 Deviation of individual measurement results at each site from the average arithmetic value of the measurement results for this section should not exceed 10%. The measurement results that do not satisfy the specified condition are not taken into account when calculating the average arithmetic value of an indirect indicator for this site. The total number of measurements on each site when calculating the average arithmetic must comply with the requirements of the table.

7.1.5 Concrete strength in the controlled structure of the structure is determined by the average value of the indirect indicator on the calibration dependence established in accordance with the requirements of the section, provided that the calculated value of the indirect indicator is within the established (or tied) dependence (between the smallest and the greatest values strength).

7.1.6 The roughness of the surface of the concrete section of structures when tested by the methods of rebound, a shock pulse, plastic deformation should correspond to the roughness of the surface of the construction sites (or cubes) tested during the establishment of calibration dependence. In the necessary cases, it is allowed to clean the surface of the structure.

When using the plastic deformation method at indulgence, if the zero count is removed after the application of the initial load, the requirements for the roughness of the surface of the concrete design are not presented.

7.2.1 Tests are carried out in the following sequence:

The position of the device when testing the design relative to the horizontal is recommended to be taken as as in the establishment of calibration dependence. With a different position of the device, it is necessary to amend the indicators in accordance with the instruction manual;

7.3.1 Tests are carried out in the following sequence:

The device is placed so that the force is applied perpendicular to the surface test in accordance with the instruction manual;

When using a spherical indenter to facilitate measurements of the diameters of prints, the test is allowed through the sheets of copier and white paper (in this case, the tests for establishing calibration dependences are carried out using the same paper);

Fix the values \u200b\u200bof the indirect characteristic in accordance with the instruction manual of the device;

Calculate the average value of the indirect characteristic on the construction site.

7.4.1 Tests are carried out in the following sequence:

The device is placed so that the force is applied perpendicular to the surface test in accordance with the instruction manual;

The position of the device when testing the design relative to the horizontal is recommended to be taken as as well as when tested when setting calibration dependence. With a different position of the device, it is necessary to amend the testimony in accordance with the instruction manual;

Fix the value of the indirect characteristic in accordance with the instruction manual;

Calculate the average value of the indirect characteristic on the construction site.

7.5.1 When tested by the method of separation, the plots should be located in the zone of the lowest stresses caused by the operational load or force the compression of pre-stressed reinforcement.

7.5.2 Testing is carried out in the following sequence:

In the area of \u200b\u200bthe disk glue, the surface layer of the concrete is removed with a depth of 0.5 - 1 mm and purify the surface from dust;

The disc is glued to concrete, pressing the disk and removing the excess glue outside the disk;

The device is connected to the disk;

The load smoothly increases with a speed (1 ± 0.3) kN / s;

Measure the area of \u200b\u200bprojection of the surface of the separation on the disc plane with an error of ± 0.5 cm 2;

The value of the conditional voltage in concrete during the separation as the ratio of the maximum extension force to the area of \u200b\u200bthe surface of the separation surface is determined.

7.5.3 Test results do not take into account if the concrete revealed the reinforcement or the area of \u200b\u200bprojection of the separation surface was less than 80% of the area of \u200b\u200bthe disk.

7.6.1 When tested by the method of separation with the rolling, the sections should be located in the zone of the lowest stresses caused by the operational load or force the compression of pre-hard fittings.

7.6.2 Tests are carried out in the following sequence:

If the anchor device was not installed before concreting, then the hole is performed in the concrete, the size of which is chosen in accordance with the instruction manual, depending on the type of anchor device;

The hole is fixed with an anchor device to a depth provided for by the instruction manual, depending on the type of anchor device;

The device is connected to an anchor device;

The load is increased at a speed of 1.5 - 3.0 kN / s;

Fix the testing of the device of the device R 0 and the magnitude of the surcharge anchor Δ h. (the difference between the actual depth of the separation and depth of the sealing of the anchor device) with an accuracy of at least 0.1 mm.

7.6.3 Measured Value R 0 multiplied by the correction coefficient γ, determined by the formula

where h. - working depth of sealing anchor device, mm;

Δ h. - The magnitude of the surcharge of anchor, mm.

7.6.4 if the greatest and the smallest dimension The eliminated part of the concrete from the anchor device to the borders of the destruction on the design surface differ more than twice, as well as if the depth of the breakdown differs from the depth of the anchoring device by more than 5% (Δ h. > 0,05h., γ\u003e 1,1), the test results are allowed to take into account only for the approximate assessment of concrete strength.

Note - Approximate values \u200b\u200bof concrete strength are not allowed to be used to assess the concrete class by strength and constructing calibration dependencies.

7.6.5 Test results are not taken into account if the depth of the exhaust differs from the depth of sealing anchor device by more than 10% (δ h. > 0,1h.) Or the fittings were naked at a distance from anchor device, less than the depth of its sealing.

7.7.1 When testing the rib ribbling method on the test section, there should be no cracks, concrete glands, inapplications or shells with a height (depth) of more than 5 mm. Plots should be located in the zone of the smallest stresses caused by the operational load or force of the compression of pre-hard fittings.

7.7.2 Testing is carried out in the following sequence:

The device is fixed on the design, apply the load at no more than (1 ± 0.3) kN / s;

Fix the reading of the device's power meter;

Measure the actual depth of the rock;

Determine the average value of the brightness.

7.7.3 Test results are not taken into account if the reinforcement was naked when the concrete was naked or the actual depth of the spill was different from the more than 2 mm given.

8 Processing and design results

8.1 Test results are present in the table in which:

Type of design;

Design class of concrete;

Age of concrete;

The strength of the concrete of each projected section of the software;

The average strength of concrete design;

Design zones or its parts subject to requirements.

The form of the test results table is shown in the application.

8.2 Processing and assessment of compliance with the established requirements for the values \u200b\u200bof the actual strength of concrete obtained using the methods given in this standard are carried out according to GOST 18105.

Note - statistical assessment of the class of concrete based on test resultsGOST 18105. (schemes "A", "B" or "B") in cases where concrete strength is determined by graduation dependence built in accordance with the section . When using previously installed dependencies by binding them (by application ) Statistical control is not allowed, and the assessment of the class of concrete is carried out only according to the scheme "G"GOST 18105.

8.3 The results of determining the strength of concrete Mechanical methods of non-destructive testing are issued in the conclusion (protocol) in which the following data leads:

About tried structures with an indication of the project class, the date of concreting and testing or age of concrete at the time of testing;

On the applied methods for monitoring the strength of concrete;

About the types of devices with factory numbers, information about the calibration of devices;

On adopted calibration dependences (equation of dependence, parameters of addiction, compliance with the conditions for the use of calibration dependence);

Used to build a calibration dependence or its binding (date and test results of non-destructive indestructible and direct or destructive methods, corrective coefficients);

On the number of sections of determining concrete strength in structures with their location;

Test results;

Methodology, results of processing and evaluation of the obtained data.

Appendix A.
(mandatory)
Standard Test Scheme by Rockwing

A.1 Standard test diagram by the method of separation with the rocking provides for testing while complying with the requirements.

A.2 Standard test diagram Applicable in the following cases:

Heavy concrete tests with compression strength from 5 to 100 MPa;

Test lung concrete compressive strength from 5 to 40 MPa;

The maximum fraction of large concrete aggregate is no more working depth of sealing anchor devices.

A.3 Supports of the loading device must evenly lie down to the surface of concrete at least 2 h. from the axis of the anchor device where h. - Working depth of sealing anchor device. Test diagram is shown in the figure.

1 2 - support of the loading device;
3 - gripping the loading device; 4 - transitional elements, traction; 5 - anchor device;
6 - Embosed concrete (cone separation); 7 - Test design

Figure A.1 - Scheme of testing by the method of separation with the rock

A.4 Standard Test Scheme by the method of separation with the crease, the use of three types of anchor devices is provided (see Figure). Anchor device of type I is installed in constructs during concreting. Anchor devices of types II and III are installed in the hole prepared in the design.

1 - working rod; 2 - work rod with a slot cone; 3 - segment corrugated cheeks;
4 - support rod; 5 - work rod with a hollow sensor cone; 6 - Leveling washer

Figure A.2 - Types of anchor devices for standard test diagram

A.5 The parameters of the anchor devices and the values \u200b\u200bof the measured concrete strength allowed for them standard scheme Tests are specified in the table. For lightweight concrete, only anchor devices with an embedding depth of 48 mm are used for the standard test diagram.

Table A.1 - Anchor Device Parameters with Standard Test Scheme

Type anchor Devices	Anchor diameter Devicesd., mm	Depth of embedding anchor devices, MM.		Permissible for anchor Range of measurement of strength on concrete compression, MPa
Type anchor Devices	Anchor diameter Devicesd., mm	working h.	full h "	heavy	easy
				45 - 75
				10 - 50	10 - 40
				40 - 100
				5 - 100	5 - 40
				10 - 50

A.6 The designs of the anchors of types II and III should provide a preliminary (before the application) compression of the walls of the opening on the working depth of the seal h. and checking slippage after testing.

Appendix B.
(mandatory)
Standard Test Scheme Rib Rib

B.1 Standard Test Scheme The rib method provides for testing when compliance with the requirements -.

B.2 Standard Test Scheme Applicable in the following cases:

The maximum fraction of large concrete aggregate is not more than 40 mm;

Heavy concrete tests with compression strength from 10 to 70 MPa on granite and limestone crushed.

B.3 For testing, an appliance consisting of a power exclusion with a block of a power measuring and gripping with a cleaner is used for local ribs design. Test diagram is shown in the figure.

1 - appliance with loading device and power meter; 2 - reference frame;
3 - Caulible concrete; 4 - test design; 5 - grip with a brass

Figure B.1 - Test Scheme by Rib Ribbon

B.4 When the edge of the ribs must be provided with the following parameters:

Depth of Rocking a. \u003d (20 ± 2) mm;

Rock width b. \u003d (30 ± 0.5) mm;

The angle between the direction of the load and the normal to the loaded surface of the design β \u003d (18 ± 1) °.

Appendix B.
(recommended)
Conditioning dependence for the separation method with the crewing

When conducting tests by the method of separation with the rolling according to the standard scheme, according to the application of the cubic strength of concrete concrete R., MPa is allowed to calculate on gradual dependence by the formula

R. = m. 1 m. 2 P.,

where m. 1 - the coefficient that takes into account the maximum size of a large aggregate in the zone is taken out of equal to 1 with a filler size of less than 50 mm;

m. 2 - the coefficient of proportionality for the transition from the effort to pull out kilonutytones to concrete strength in megapascals;

R - Effort of feeding anchor device, kN.

When testing heavy concrete Tools 5 MPa and more and lightweight concrete strength from 5 to 40 MPa proportionality coefficient m. 2 Take the table.

Table B.1.

Type anchor Devices	Range Measured Concrete strength on compression, MPa	Anchor diameter Devicesd., mm	The depth of embelling anchor Devices, mm.	The value of the coefficientm. 2 for concrete
Type anchor Devices	Range Measured Concrete strength on compression, MPa	Anchor diameter Devicesd., mm	The depth of embelling anchor Devices, mm.	heavy	easy
	45 - 75
	10 - 50
	40 - 75
	5 - 75
	10 - 50

Factors m. 2 When testing heavy concrete with medium strength above 70 MPa should be taken according to GOST 31914.

Appendix G.
(recommended)
Graduation Dependence for Rib Range Method
With a standard test diagram

When testing the rib ribbing using the standard diagram according to the application of cubic strength to concrete compression on the granite and lime crushed R., MPa is allowed to calculate on gradual dependence by the formula

R. = 0,058m.(30R + R 2),

where m. - The coefficient that takes into account the maximum size of a large aggregate and is taken equal to:

1.0 - with aggregate size of less than 20 mm;

1.05 - with aggregate size of 20 to 30 mm;

1.1 - in terms of aggregate size from 30 to 40 mm;

R - The Effort of Rocking, KN.

Appendix D.
(mandatory)
Requirements for mechanical testing

Table D.1

Name characteristics of devices

Device characteristics for method

elastic
rebound

shock
Impulse

plastic
deformations

oterval

rocking
ribs

otervoy S.
Rocking

Hardness of the drummer, brisk or an HRCE indenter, not less

Roughness of the contact part of the drummer or indenter, microns, not more

The diameter of the drummer or indenter, mm, not less

The thickness of the edges of the disk indenter, mm, not less

The angle of the conical indenter

30 ° - 60 °

The diameter of the imprint,% of the diameter of the indenter

20 - 70

Perpendicular admission when the load application at a height is 100 mm, mm

Energy impact, J, not less

0,02

Load increase speed, KN / sThe dependence equation "indirect characteristic - strength" is taken linear by the formula

E.2 Rejection Test Results

After constructing calibration dependences by the formula (), it is adjusted by rejection of single test results that do not satisfy the condition:

where the average value of concrete strength on gradual dependence is calculated by the formula

here is values R I. H, R I. F ,, N. - See explication to formulas (), ().

E.4 Correction of calibration dependence

The adjustment of the installed calibration dependence taking into account additionally the resulting test results should be carried out at least once a month.

When adjusting a calibration dependency to existing test results, at least three new results obtained with minimal, maximum and intermediate values \u200b\u200bof the indirect indicator are added.

As data accumulates to build a calibration dependence, the results of previous tests, starting from the very first, rejected so that the total number of results does not exceed 20. After adding new results and rejection of the oldest and maximum values \u200b\u200bof indirect characteristic, the gradual dependence and its parameters are set again by formulas. () - ().

E.5 Terms of use of calibration dependence

The use of calibration dependence to determine the strength of concrete for the present standard is allowed only for the values \u200b\u200bof the indirect characteristic falling in the range from H. MIN BE N. Mach.

If the correlation coefficient r. < 0,7 или значение , Conduct control and assessment of strength on dependency obtained are not allowed.

Appendix J.
(mandatory)
Conditional Dependency Binding Method

G.1 The value of concrete strength, determined using the graded dependence mounted for concrete, differing from the subject, is multiplied by the coincidence coefficient K. from. Value K. C are calculated by the formula

where R. OS. I. - Concrete strength in i.- plot determined by the method of separation with the crease or test of cores according to GOST 28570;

R. cosv I. - Concrete strength in i.- plot, defined by any indirect method for used calibration dependence;

n. - The number of test sections.

G.2 When calculating the coincidence coefficient, conditions must be observed:

The number of test sections taken into account when calculating the coefficient of coincidence, n. ≥ 3;

Each particular value R. OS. I. /R. cosv I. There must be at least 0.7 and not more than 1.3:

1 per 4 m length of linear structures;

1 on 4 m 2 square flat designs.

Appendix K.
(recommended)
Test results presentation table form

Name of structures (parties of structures), Project class of strength Concrete, concreting date or age of concrete tested Designs	Designation 1)	Plot number according to the scheme or location in axes 2)	Concrete strength, MPa		Strength class concrete 5)
			plot 3)	average 4)






1) Brand symbol and (or) the design of the construction in the axes, the design zones, or parts of the monolithic and collection-monolithic design (capture), for which the standard of concrete strength is determined. 2) The total number and location of the plots in accordance with . 3) Concrete strength plot in accordance with . 4) Average strength Concrete design, design zones or part of monolithic and collected-monolithic design with the number of sections that meet the requirements . 5) The actual strength class of concrete design or part of the monolithic and collection-monolithic design according to paragraphs 7.3 - 7.5GOST 18105. Depending on the selected control scheme. Note - Presentation in the "Concrete Strength Class" column of assessment values \u200b\u200bof the class or values \u200b\u200bof the required concrete strength for each site separately (Evaluation of the strength class in one section) is not allowed.

Keywords: constructive heavy and lightweight concrete, monolithic and prefab concrete and reinforced concrete products, designs and structures, mechanical methods for determining compression strength, elastic rebound, impact pulse, plastic deformation, separation, ribbing, chuck

V.A. Clevtsov, Dr. Tehn. Sciences (head of the topic); M.G.Korvevitskaya, Cand. tehn sciences; Yu.K. Matsev; V.N.Artamonova; N.S.Vostrov; A.A. Grebenik; G.V.Sizov, Cand. tehn sciences; D.A. Korshunov, Cand. tehn sciences; M.V. Sididenko, Cand. tehn sciences; Yu.I. Kurash, Cand. tehn sciences; A.M. Leschinsky, Cand. tehn sciences; V.R.Abramovsky; V.A.Dorf, Cand. tehn sciences; E.G.Sorkin, Cand. tehn sciences; V.L. Chernyakhovsky, Cand. tehn sciences; I.O. Krolo, Cand. tehn sciences; S.Y.Vomatechenko; I.E. Ganin; O.Yu.Sammal, Cand. tehn sciences; A.A.Rulkov, Cand. tehn sciences; P.L.Talberg; A.I. Markov, Cand. tehn sciences; R.O. Krasnovsky, Cand. tehn sciences; L.S.pavlov, Cand. tehn sciences; M.Yu. Leschinsky, Cand. tehn sciences; G.A. Merkivsky; I.E.shkolnik, Cand. tehn sciences; I.Y. Lapenis, G.I. Winggarten, Cand. tehn sciences; N. B. Zhukovskaya; S.P. Abramova; I.N. Nagornok

This standard applies to heavy and lightweight concrete and establishes methods for determining compression strength in structures on elastic rebound, impact pulse, plastic deformation, separation, ribs, and leaving the rolling.

The size of the imprint on concrete (diameter, depth, etc.) or the ratio of the diameters of prints on concrete and the standard sample when the indenter is impaired or indenting an indenter into the surface of the concrete;

The value of the voltage required for the local destruction of concrete when the metal disk was glued to it, equal to the separation force divided into the area of \u200b\u200bprojection of the surface of the concrete separation to the disc plane;

1.3. Mechanical non-destructive testing methods are used to determine the strength of the concrete of all types of normalized strength controlled according to GOST 18105, as well as to determine the strength of concrete during examination and rejection of structures.

1.4. Tests are carried out at a positive temperature of concrete. It is allowed upon examination of structures to determine the strength at a negative temperature, but not lower than minus 10 ° C, provided that by the time of freezing, the structure was at least one week at a positive temperature and relative humidity of air no more than 75%.

1.5. Assessment of the conformity of the values \u200b\u200bof the actual strength of concrete obtained using the methods given in this standard established requirements are produced according to GOST 18105.

2.1. Concrete strength is determined using instruments intended to determine the indirect characteristics that have passed the metrological certification according to GOST 8.326 * and meet the requirements shown in Table 2.

Name characteristics of devices	Device characteristics for method
	elastic rebound	impact impulse	plastic deformation	oterval	ribs ribs	running with a smoking
Hardness of the drummer, brisk or an HRCE indenter, not less
Roughness of the contact part of the drummer or indenter, microns, not more
The diameter of the drummer or indenter, mm, not less
The thickness of the edges of the disk indenter, mm, not less	10
The angle of the conical indenter	30-60 °
The diameter of the imprint,% of the in the indenter diameter	20-70
Admission perpendicularity When applying a load at a height of 100 mm, mm
Energy impact, J, not less	0,02
Load increase speed, KN / s	1,5*	0,5-1,5	0,5-1,5	1,5-3,0
Error of measuring the load from the measured load,%, not more	5*

2.2. The tool for measuring the diameter or depth of prints (angular scale according to GOST 427, the caliper according to GOST 166 et al.) Used for the method of plastic deformations, should ensure measurements with an error of no more than ± 0.1 mm, and the tool for measuring the imprint depth (indicator hourly type according to GOST 577, etc.) - with an error of no more than ± 0.01 mm.

Other anchor devices are allowed, the sealing depth of which should be no less than the maximum size of the large-scale concrete aggregate of the test structure.

2.5. For the separation method, it is necessary to use steel discs with a diameter of at least 40 mm, a thickness of at least 6 mm and at least 0.1 diameters, with the roughness parameter of the glued surface of at least 20 microns according to GOST 2789. The glue for the disk glue should provide strength at which

3.1. To determine the strength of concrete in structures, there is a graduation dependence between the strength of the concrete and the indirect characteristic of the strength (in the form of a graph, table or formula).

For the rolling separation method, in the case of the use of anchor devices in accordance with Appendix 2, and for the rib, in the case of applying devices in accordance with Annex 3, it is allowed to use the calibration dependences given in Appendices 5 and 6, respectively.

Commissioned by order of the Federal Agency for Technical Regulation and Metrology of September 25, 2015 N 1378-ST

Interstate Standard GOST 22690-2015

"Concretes. Determining the strength of non-destructive testing mechanical methods"

Concretes. Determination Of Strength by Mechanical Methods of NondestRUCTIVE Testing

Instead of GOST 22690-88

Preface

Objectives, basic principles and the main procedure for working on interstate standardization GOST 1.0-92 "Interstate standardization system. Basic provisions" and GOST 1.2-2009 "Interstate standardization system. Standards interstate, rules and recommendations on interstate standardization. Development rules, adoption, Applications, updates and cancellation "

Information about standard

1 Developed by the structural unit of JSC "Construction" by the research, research, design and design and technological institution of concrete and reinforced concrete. A.A. Govnieva (NIIZB)

2 Submitted by the Technical Committee on Standardization TC 465 "Construction"

3 Adopted by the Interstate Council for Standardization, Metrology and Certification (Protocol of June 18, 2015 N 47)

Short name of the country on MK (ISO 3166) 004-97	Country code according to MK (ISO 3166) 004-97	Abbreviated name of the National Standardization Authority
		Ministry of Economy of the Republic of Armenia
Belarus		Gosstandart of the Republic of Belarus
Kazakhstan		Gosstandart of the Republic of Kazakhstan
Kyrgyzstan		Kyrgyzstandart
		Moldova Standard
		Rosstandard.
Tajikistan		Tajikstandard

4 by order of the Federal Agency for Technical Regulation and Metrology of September 25, 2015 N 1378-ST Interstate Standard GOST 22690-2015 was introduced as a national standard Russian Federation From April 1, 2016

5 This standard takes into account the main regulations In terms of requirements for mechanical methods of non-destructive monitoring of concrete strength of the following European regional standards:

EN 12504-2: 2001 Testing Concrete In Structures - Part 2: Non-Destructive Testing - Determination of Rebound Number (Concrete Testing in Designs. Part 2. Unbrakable control. Definition of criterion of rebound);

EN 12504-3: 2005 Testing Concrete in Structures - Determination of Pull-Out Force (Concrete Testing in Designs. Part 3. Definition of bulk effort).

The degree of conformity is non-equivalent (NEQ)

6 instead of GOST 22690-88

1 area of \u200b\u200buse

2 Regulatory references

This standard uses regulatory references to the following interstate standards:

GOST 166-89 (ISO 3599-76) caliper. Technical conditions

GOST 577-68 Watch type indicators with division price 0, 01 mm. Technical conditions

GOST 2789-73 surface roughness. Parameters and characteristics

GOST 10180-2012 Concretes. Methods for determining the strength of control samples

GOST 18105-2010 Concretes. Rules for monitoring and assessing strength

GOST 28243-96 Pyrometers. General technical requirements

GOST 28570-90 concrete. Methods for determining the strength of samples selected from the designs

GOST 31914-2012 High-strength heavy and fine-grained concrete for monolithic structures. Rules of control and quality assessment

Note - When using this standard, it is advisable to check the action of reference standards in the public information system - on the official website of the Federal Agency for Technical Regulation and Metrology on the Internet or on the National Standards Annual Information Signal, which is published as of January 1 of the current year, and on issues of the monthly information pointer "National Standards" for the current year. If the reference standard is replaced (changed), then when using this standard should be guided by replacing (modified) standard. If the reference standard is canceled without replacement, the position in which the reference is given to it is applied in a portion that does not affect this link.

3 Terms and Definitions

In this standard, the terms according to GOST 18105 are applied, as well as the following terms with the corresponding definitions;

3.2 Non-destructive mechanical methods for determining the strength of concrete: Determination of concrete strength directly in the design with a local mechanical effect on concrete (blow, separation, chip, indulgence, separation with the rocking, elastic rebound).

3.3 Indirect non-destructive methods for determining concrete strength: determination of concrete strength on pre-installed calibration dependencies.

3.4 Straight (standard) non-destructive methods for determining concrete strength: methods involving standard test diagrams (separating the rolling and rocking of the edge) and allowing the use of known graduating dependencies without binding and adjustment.

3.5 Conditional dependence: Graphic or analytical dependence between the indirect characteristic of the strength and strength of concrete on a compression determined by one of the destructive or direct non-destructive methods.

3.6 indirect strength characteristics (indirect indicator): the magnitude of the applied force during the local destruction of concrete, the magnitude of the rebound, the energy of the impact, the size of the imprint or other instrument reading when measuring concrete strength non-destructive mechanical methods.

4 General

4.1 Non-destructive mechanical methods are used to determine the strength of concrete for compression in the intermediate and design age installed project documentation and in the age of the project, during the examination of the structures.

4.2 Non-destructive mechanical methods for determining concrete strength, established by this standard, are subdivided by the type of mechanical impact or determined indirect characteristics on the method:

Elastic rebound;

Plastic deformation;

Shock impulse;

Ottay with rocking;

Ribs ribs.

4.3 Non-destructive mechanical methods for determining concrete strength are based on concrete strength with indirect strength characteristics:

The method of elastic rebound on the connection of concrete strength with the value of the rebound of the bridge from the surface of the concrete (or the drummer pressed to it);

Plastic deformation method on concrete strength with imprint size on concrete design (diameter, depth, etc.) or the ratio of the prints of the imprint on concrete and standard metal sample When the indenter is impaired or indenting an indenter into the surface of concrete;

The impact pulse method for the connection of concrete strength with the energy of the impact and its changes at the time of the collision of the coach with the surface of the concrete;

The separation method for the supply of the voltage required for the local destruction of concrete when the metal disk is glued to it, equal to the separation of the separation, divided into the area of \u200b\u200bthe projection of the concrete separation on the disc plane;

The separation method with the creation of concrete strength with the value of the efforts of the local destruction of concrete when the anchor device is pulled from it;

The rib of ribs on the connection of concrete strength with the value of the effort required to rock the concrete section on the rib design.

4.4 In general, non-destructive mechanical methods for determining concrete strength are indirect non-destructive methods for determining strength. Concrete strength in structures are determined by experimentally installed calibration dependencies.

4.5 The separation method with the rolling during testing in accordance with the standard scheme for Appendix A and the rib ribbon method when conducting tests in accordance with the standard scheme for Appendix B are direct non-destructive methods for determining concrete strength. For direct non-destructive methods allowed to use calibration dependences set in applications B and G.

Note - Standard test diagrams are applicable in a limited range of concrete strength (see Appendices A and B). For cases that do not relate to standard test diagrams, there should be calibration dependencies in general rules.

4.6 The test method should be selected taking into account the data shown in Table 1, and additional restrictions installed by the manufacturers of specific measurement tools. The use of methods outside of the concrete strength recommended in Table 1 is allowed in a scientific and technical justification based on research results using measurement tools that have passed the metrological certification for the extended range of concrete strength.

Table 1

4.7 Determination of the strength of heavy concrete C60 design classes and higher or with the average strength of concrete on compression R m ≥70 MPa in monolithic structures, it is necessary to carry out the provisions of GOST 31914.

4.8 Concrete strength is determined in areas of structures that do not have visible damage (detachment of the protective layer, cracks, cavities, etc.).

4.9 The age of concrete controlled structures and its sites should not differ from the age of concrete of structures (sections, samples) tested to establish calibration dependence, more than 25%. Exceptions are controlling the strength and construction of calibration for concrete, which exceeds two months. In this case, the difference in the age of individual structures (sections, samples) is not regulated.

4.10 Tests are carried out at a positive temperature of concrete. It is allowed to carry out tests under the negative temperature of concrete, but not lower than minus 10 ° C, when establishing or binding a graduation dependence, taking into account the requirements 6.2.4. The temperature of the concrete during testing should correspond to the temperature provided for by the operating conditions of the instruments.

The calibration dependences mounted at a concrete temperature below 0 ° C are not allowed to be used at positive temperatures.

4.11 If necessary, testing concrete constructs after heat treatment at a surface temperature of T≥40 ° C (for controlling the release, gear and coating strength of concrete), the calibration dependence is set after determining the strength of concrete in the design of an indirect non-destructive method at a temperature T \u003d (t ± 10) ° C, and concrete testing by direct non-destructive method or testing of samples - after cooling at normal temperature.

5 Measurement Means, Equipment and Tool

5.1 Measurement Means and Mechanical Test Instruments, designed to determine concrete strength, must be certified and are attributed in the prescribed manner and must comply with the requirements of Appendix D.

5.2 Indications of devices graded in units of concrete strength should be considered as an indirect indicator of concrete strength. These instruments should be used only after establishing the calibration dependency "The testing of the device - the strength of concrete" or the binding of the dependence installed in the device in accordance with 6.1.9.

5.3 Instrument for measuring the diameter of prints (caliper according to GOST 166), used for the method of plastic deformations, should ensure measurement with an error of no more than 0, 1 mm, tool for measuring the imprint depth (indicator of the hourly type according to GOST 577, etc.) - with an error Not more than 0, 01 mm.

5.4 Standard test diagrams of testing by the method of separation with the crease and chip edges provide for the use of anchor devices and captures in accordance with applications A and B.

5.6 For the separation method, it is necessary to use steel discs with a diameter of at least 40 mm, a thickness of at least 6 mm and at least 0, 1 diameter, with the roughness parameters of the glued surface of at least Ra \u003d 20 microns according to GOST 2789. The adhesive for the disk glue must provide adhesion strength With concrete, at which destruction occurs in concrete.

6 Test preparation

6.1 Procedure for preparing for testing

6.1.2 Graduation dependence is established on the basis of the following data:

The results of parallel tests of the same stations of structures by one of the indirect methods and a direct non-destructive method for determining concrete strength;

Test results of standard concrete samples by one of the indirect non-destructive methods for determining concrete strength and mechanical tests according to GOST 10180.

6.1.3 For indirect non-destructive methods for determining the strength of concrete, the calibration dependence is set for each type of normalized strength specified in 4.1 for the concrete of one nominal composition.

It is allowed to build one graduation dependence for the concretes of one type with one type of large aggregate, with a single production technology, differing from the nominal composition and the value of the normalized strength subject to the requirements of 6.1.7

6.1.4 The permissible difference between the age of the concrete of individual structures (sections, samples) when setting the calibration dependence on the age of concrete of the controlled design, accepted by 4.9.

6.1.5 For direct non-destructive methods of 4.5, it is allowed to use the dependences given in applications B and G for all types of normalized concrete strength.

It is recommended to use a linear dependence of the form R \u003d a + b K (where R is the strength of concrete, K is an indirect indicator). The method of establishing, evaluating parameters and determining the conditions for the application of a linear graduation dependence is given in Appendix E.

6.1.7 When constructing the calibration dependences of the deviation of single values \u200b\u200bof the strength of concrete R i f from the average value of the concrete strength of the sections or samples of R̅ F used to construct calibration dependence, should be within:

From 0, 5 to 1, 5 mean values \u200b\u200bof concrete strength R̅ F with R̅ F ≤ 20 MPa;

From 0, 6 to 1, 4 average concrete strength R̅ F with 20 MPa< R̅ ф ≤ 50 МПа;

From 0, 7 to 1, 3 average concrete strength R̅ F at 50 MPa< R̅ ф ≤ 80 МПа;

From 0, 8 to 1, 2 averages of concrete strength R̅ F with R̅ F\u003e 80 MPa.

6.1.9 It is allowed to apply indirect non-destructive methods for determining concrete strength, using graded dependences mounted for concrete, differing from the composition under the composition, age, experimental conditions, humidity, with reference in accordance with the method of Appendix J.

6.1.10 without binding to specific conditions by Appendix W Conducting dependencies established for concrete, different from the subject, it is allowed to be used only to obtain approximate values \u200b\u200bof strength. It is not allowed to use indicative strength values \u200b\u200bwithout reference to specific conditions for assessing the concrete class by strength.

6.2 Construction of calf dependence on the results of concrete strength tests in structures

6.2.1 When constructing a calibration dependence on the results of the tests of concrete strength in structures, the dependence is set according to the single values \u200b\u200bof the indirect indicator and the strength of the concrete of the same sections of the structures.

For the unit value of the indirect indicator, the average value of the indirect indicator in the area is taken. For the unit value of concrete strength, the strength of the concrete section is taken, determined by a direct non-destructive method or test of selected samples.

6.2.2 The minimum number of single values \u200b\u200bfor building a calibration dependence on the results of the tests of concrete strength in structures - 12.

6.2.3 When constructing a calibration dependence on the results of the tests of concrete strength in the structures of non-test structures or their zones, the measurements of the indirect non-destructive method are pre-carried out according to the requirements of section 7.

Then selected areas in the amount provided for by 6.2.2, on which the maximum, minimum and intermediate values \u200b\u200bof the indirect indicator are obtained.

After testing by an indirect non-destructive method, the plots are tested by a direct non-destructive method or select samples for the test according to GOST 28570.

6.2.4 To determine the strength at a negative temperature of concrete, the sections selected for constructing or binding calibration dependences are first tested by an indirect non-destructive method, and then samples are taken for subsequent tests at a positive temperature or heated by external heat sources (infrared emitters, thermal guns, etc. ) At a depth of 50 mm to a temperature not lower than 0 ° C and experience a direct non-destructive method. Monitoring the temperature of he warmed concrete is carried out at the depth of the installation of anchor device in the prepared hole or on the surface of the unit, a contactless manner with a pyrometer according to GOST 28243.

6.3 Construction of graduation dependence on control samples

For the isolated value of the indirect indicator, the average value of indirect indicators for a series of samples or for a single sample is taken (if the calibration addiction is installed in separate samples). For the unit value of concrete strength, concrete strength in the GOST 10180 series or one sample (graduation dependence on separate samples) takes. Mechanical tests of samples according to GOST 10180 are carried out immediately after testing by an indirect non-destructive method.

The unit values \u200b\u200bof the strength of the concrete of sample cubes used to construct calibration addiction should correspond to the expectations on the production of deviations, while be within the ranges set by 6.1.7.

When establishing a calibration dependence for the separation method with the cream, the main and control samples of 6.3.4 are manufactured. On the main samples, the indirect characteristic is determined, the control samples are tested according to GOST 10180. Basic and control samples must be made of one concrete and to solve in the same conditions.

6.3.4 Sample sizes should be chosen in accordance with the greatest size of the filler in the concrete mixture according to GOST 10180, but not less:

100 x 100 x 100 mm for rebound methods, shock pulse, plastic deformation, as well as for the method of separation with the twilight (control samples);

200 x 200 x 200 mm for the method of rocking the rib design;

300 x 300 x 300 mm, but with the size of the edge of at least six depth of the installation of an anchor device for the separation method with the rocky (main samples).

6.3.5 To determine the indirect characteristics of strength, tests are carried out according to the requirements of section 7 on the side (in the direction of concreting) the edges of the sample cubes.

The total number of measurements on each sample for the method of elastic rebound, the shock pulse, plastic deformation during the strike should be at least the set number of tests on the site according to Table 2, and the distance between the shocks is at least 30 mm (15 mm for the impact pulse method). For the method of plastic deformation under induction, the number of tests on each face should be at least two, and the distance between the test sites is at least two diameters of the prints.

When establishing a calibration dependence for the rib method, the ribs are carried out by one test on each side edge.

When establishing a calibration dependence for the rolling separation method, one tests on each side face of the main sample is carried out.

6.3.6 When testing the method of elastic rebound, a shock pulse, plastic deformation when the samples should be clamped in a press with an effort of at least (30 ± 5) kN and no more than 10% of the expected value of the destructive load.

7 Testing

7.1 General requirements

7.1.1 The number and location of controlled areas in constructions must comply with the requirements of GOST 18105 and specify in design documentation on the design or set aside:

Control objectives (determination of the actual class of concrete, platform or vacation strength, detecting low strength sections, etc.);

Type of design (columns, beams, stoves, etc.);

Placement of the capture and order of concreting;

Reinforcement designs.

The rules for appointing the number of sections of the monolithic and prefabricated structures during the monitoring of concrete strength are given in Appendix I. When determining the strength of the concrete of the examined structures, the number and location of the sites should be accepted under the survey program.

7.1.2 Tests are carried out on a section of a construction area from 100 to 900 cm 2.

7.1.3 Total number of measurements on each site, the distance between the measurements in the area and the edge of the structure, the thickness of the structures on the measurement site should be at least the values \u200b\u200bshown in Table 2 depending on the test method.

Table 2 - Test Requirements Requirements

Name method	Total number of measurements on the site	The minimum distance between the measurement places on the site, mm	Minimum distance from the edge of the design to the place of measurement, mm	Minimal thickness Designs, mm.
Elastic rebound
Impact impulse
Plastic deformation
Rubbing ribs
		2 disk diameters
Targeting with a smoking at the working depth of the entry of an anchor H: ≥ 40 mm

7.1.5 Concrete strength in the controlled structure of the structure is determined by the average value of the indirect indicator on the calibration dependence set in accordance with the requirements of section 6, provided that the calculated value of the indirect indicator is within the established (or tied) dependence (between the smallest and the largest values strength).

7.2 Method of elastic rebound

7.2.1 Tests are carried out in the following sequence:

7.3 Method of plastic deformations

7.3.1 Tests are carried out in the following sequence:

The device is placed so that the force is applied perpendicular to the surface test in accordance with the instruction manual;

Fix the values \u200b\u200bof the indirect characteristic in accordance with the instruction manual of the device;

Calculate the average value of the indirect characteristic on the construction site.

7.4 Impact Impulse Method

7.4.1 Tests are carried out in the following sequence:

The device is placed so that the force is applied perpendicular to the surface test in accordance with the instruction manual;

Fix the value of the indirect characteristic in accordance with the instruction manual;

Calculate the average value of the indirect characteristic on the construction site.

7.5 Outflow method

7.5.1 When tested by the method of separation, the plots should be located in the zone of the lowest stresses caused by the operational load or force the compression of pre-stressed reinforcement.

7.5.2 Testing is carried out in the following sequence:

In place of the disk row, the surface layer of the concrete is deplined 0, 5 - 1 mm and purify the surface from dust;

The disc is glued to concrete, pressing the disk and removing the excess glue outside the disk;

The device is connected to the disk;

The load smoothly increase at a rate (1 ± 0, 3) kN / s;

Measure the area of \u200b\u200bprojection of the surface of the separation on the disc plane with an error of ± 0, 5 cm 2;

The value of the conditional voltage in concrete during the separation as the ratio of the maximum extension force to the area of \u200b\u200bthe surface of the separation surface is determined.

7.6 Method of separation with the parking

7.6.2 Tests are carried out in the following sequence:

The hole is fixed with an anchor device to a depth provided for by the instruction manual, depending on the type of anchor device;

The device is connected to an anchor device;

The load is increased at a speed of 1, 5 - 3, 0 kN / s;

The reading of the Silmeter P 0 of the device P 0 and the values \u200b\u200bof the anchor ΔH (the difference between the actual depth of the outlet and the depth of the embezzlement of the anchor device) with an accuracy of at least 0, 1 mm.

7.6.3 The measured value of the pulp P 0 is multiplied by the correction coefficient γ, determined by the formula

where h is the working depth of the embezzlement of the anchor device, mm;

ΔH - the magnitude of the anchor slippage, mm.

7.6.4. If the largest and smallest dimensions of the disconnected part of the concrete from the anchor device to the borders of the destruction on the surface of the structure differ more than doubled, as well as if the depth of the breakdown differs from the depth of sealing anchor device by more than 5% (ΔH\u003e 0, 05h , γ\u003e 1, 1), then the test results are allowed to take into account only for approximate assessment of concrete strength.

Note - Approximate values \u200b\u200bof concrete strength are not allowed to be used to assess the concrete class by strength and constructing calibration dependencies.

7.6.5 Test results are not taken into account if the depth of the pulp differs from the depth of sealing anchor device by more than 10% (ΔH\u003e 0, 1H) or the fittings are naked at the distance of the otanker device, less than the depth of its sealing.

7.7 Rib Ribbon

7.7.2 Testing is carried out in the following sequence:

The device is fixed on the design, apply the load at no more than (1 ± 0, 3) kN / s;

Fix the reading of the device's power meter;

Measure the actual depth of the rock;

Determine the average value of the brightness.

7.7.3 Test results are not taken into account if the reinforcement was naked when the concrete was naked or the actual depth of the spill was different from the more than 2 mm given.

8 Processing and design results

8.1 Test results are present in the table in which:

Type of design;

Design class of concrete;

Age of concrete;

Concrete strength of each projected section 7.1.5;

The average strength of concrete design;

Design zones or its parts subject to requirements 7.1.1.

The form of the test results table is shown in Appendix K.

Note - The statistical assessment of the concrete class according to the test results is carried out according to GOST 18105 (scheme "A", B "or" B ") in cases where concrete strength is determined by the calibration dependence constructed in accordance with section 6. When using previously installed dependencies by binding them (by Appendix G), statistical control is not allowed, and the assessment of the concrete class is carried out only according to the GOST 18105 scheme.

8.3 The results of determining the strength of concrete Mechanical methods of non-destructive testing are issued in the conclusion (protocol) in which the following data leads:

About tried structures with an indication of the project class, the date of concreting and testing or age of concrete at the time of testing;

On the applied methods for monitoring the strength of concrete;

About the types of devices with factory numbers, information about the calibration of devices;

On adopted calibration dependences (equation of dependence, parameters of addiction, compliance with the conditions for the use of calibration dependence);

Used to build a calibration dependence or its binding (date and test results of non-destructive indestructible and direct or destructive methods, corrective coefficients);

On the number of sections of determining concrete strength in structures with their location;

Test results;

Methodology, results of processing and evaluation of the obtained data.

Appendix A.
(mandatory)

Standard Test Scheme by Rockwing

A.1 Standard test diagram by the method of separation with the rocking provides for testing under compliance with the requirements of A.2 - A.6.

A.2 Standard test diagram Applicable in the following cases:

Heavy concrete tests with compression strength from 5 to 100 MPa;

Tests of lightweight concrete compressive strength from 5 to 40 MPa;

The maximum fraction of large concrete aggregate is no more working depth of sealing anchor devices.

A.3 Supports of the loading device should evenly lie down to the surface of concrete at a distance of at least 2H from the axis of the anchor device, where H is the working depth of the anchor device. The test scheme is shown in Figure A.1.

1 - appliance with loading device and power meter; 2 - support of the loading device; 3 - gripping the loading device; 4 - transition elements, thrust; 5 - anchor device; 6 - disengageable concrete (cone separation); 7 - Test Design

"Figure A.1 - Test diagram by the method of separation with the rocking"

A.4 Standard Test Scheme by the method of separation with the crease, the use of three types of anchor devices is provided (see Figure A.2). Anchor device of type I is installed in constructs during concreting. Anchor devices of types II and III are installed in the hole prepared in the design.

1 - working rod: 2 - working rod with a slot cone; 3 - segment corrugated cheeks; 4 - reference rod; 5 is a working rod with a hollow sensor cone; 6 - leveling washer

"Figure A.2 - Types of anchor devices for the standard test scheme"

A.5 The parameters of the anchor devices and the values \u200b\u200bof them are valid for them measured concrete strength with a standard test diagrater are shown in Table A.1. For lightweight concrete, only anchor devices with an embedding depth of 48 mm are used for the standard test diagram.

Table A.1 - Anchor Device Parameters with Standard Test Scheme

Type of anchor device	Depth of sealing anchor devices, mm	Permissible for anchor device Range of measurements of concrete compression strength, MPa
Type of anchor device	working H.	heavy

A.6 The designs of the anchors of types II and III should provide a preliminary (up to the application of the load), comprise the walls of the opening at the working depth of the sealing H and control slippage after the test.

Appendix B.
(mandatory)

Standard Test Scheme Rib Rib

B.1 Standard test diagram of the rib ribs provides for testing when complying with B.2 - B.4 requirements.

B.2 Standard Test Scheme Applicable in the following cases:

The maximum fraction of large concrete aggregate is not more than 40 mm;

Heavy concrete tests with compression strength from 10 to 70 MPa on granite and limestone crushed.

B.3 For testing, an appliance consisting of a power exclusion with a block of a power measuring and gripping with a cleaner is used for local ribs design. The test scheme is shown in Figure B.1.

1 - appliance with loading device and power meter; 2 - reference frame; 3 - Caulible concrete; 4 - Test design. 5 - grip with a brass

"Figure B.1 - Test Scheme by Rib Ribbon"

B.4 When the edge of the ribs must be provided with the following parameters:

The depth of the brightness A \u003d (20 ± 2) mm;

Rock width B \u003d (30 ± 0, 5) mm;

The angle between the direction of the load and the normal to the loaded surface of the design β \u003d (18 ± 1) °.

Graduation dependence for the separation method with the rocking with the standard test diagram

During testing by the method of separation with the rolling according to the standard scheme, according to the application and the cube strength of concrete on the compression R, MPa, is allowed to calculate by graduation dependence by the formula

where M 1 is a coefficient that takes into account the maximum size of a large aggregate in the zone of the exhaust and taken equal to 1 with a filler size of less than 50 mm;

m 2 is the proportionality coefficient for the transition from the effort of the breakdown in kilontons to concrete strength in megapascals;

P is an error of the anchor device, KN.

When testing a heavy concrete, a strength of 5 MPa and more and lightweight concrete is a strength of 5 to 40 MPa, the value of the ratio of the M 2 proportionality is received according to Table B.1.

Table B.1.

Type of anchor device	Range of measured concrete strength on compression, MPa	Diameter of anchor device D, mm	Depth of embedding anchor device, mm	M 2 coefficient value for concrete
Type of anchor device	Range of measured concrete strength on compression, MPa	Diameter of anchor device D, mm	Depth of embedding anchor device, mm	heavy

The M 2 coefficients when testing heavy concrete with medium strength above 70 MPa should be taken according to GOST 31914.

Graduation dependence for the rib of ribs with a standard test diagram

When the test is performed by the rib ribbon method according to the application b cubic strength to concrete compression on the granite and limescale R, MPa, allowed to be calculated by graduation dependence by the formula

R \u003d 0, 058m (30p + p 2),

where M is a coefficient that takes into account the maximum size of a large aggregate and is taken equal to:

1, 0 - with aggregate size of less than 20 mm;

1, 05 - with aggregate size of 20 to 30 mm;

1, 1 - with aggregate size from 30 to 40 mm;

P is the effort of the Rocking, KN.

Appendix D.
(mandatory)

Requirements for mechanical testing

Table D.1

Name characteristics of devices	Device characteristics for method
Name characteristics of devices	elastic rebound	impact impulse	plastic deformation	ribs ribs	running with a smoking
Hardness of the drummer, brisk or an HRCE indenter, not less
Roughness of the contact part of the drummer or indenter, microns, not more
The diameter of the drummer or indenter, mm, not less
The thickness of the edges of the disk indenter, mm, not less
The angle of the conical indenter
The diameter of the imprint,% of the diameter of the indenter
Perpendicular admission when the load application at a height is 100 mm, mm
Energy impact, J, not less
Load increase speed, KN / s
Load measurement error,%, no more
* When indenting an indenter into a concrete surface.

Methods of establishing, adjusting and evaluating parameters of calibration dependencies

E.1 Equation of calibration dependence

Equation of the dependence "indirect characteristic - strength" take linear by the formula

E.2 Rejection Test Results

After constructing calibration dependences by the formula (E.1), it is adjusted by rejecting single test results that do not satisfy the condition:

where R i n is the strength of concrete in i-M plotdefined under the conditioned graduation dependence;

S - residual standard deviation, calculated by the formula

here R i F, n - see explication to the formula (E.3).

After rejection, the calibration dependence is set again according to the formulas (E.1) - (E.5) according to the remaining test results. The rejection of the remaining test results is repeated, considering the implementation of the condition (E.6) when using a new (adjusted) graduation dependence.

Private concrete strength values \u200b\u200bmust meet 6.1.7 requirements.

E.3 Parameters of graduation dependence

For adopted calibration dependences, they define:

The minimum and maximum values \u200b\u200bof the indirect characteristic H min, H Max;

RMS deviation s t. H. M constructed graduation dependence according to the formula (E.7);

Correlation coefficient of calibration dependence R by formula

where the average value of concrete strength on the calibration dependence R̅ H is calculated by the formula

here, the values \u200b\u200bof R I H, R i F, R̅ F, n - see explication to formulas (E.3), (E.6).

E.4 Correction of calibration dependence

The adjustment of the installed calibration dependence taking into account additionally the resulting test results should be carried out at least once a month.

When adjusting a calibration dependency to existing test results, at least three new results obtained with minimal, maximum and intermediate values \u200b\u200bof the indirect indicator are added.

E.5 Terms of use of calibration dependence

The use of calibration dependences to determine the strength of concrete under the present standard is allowed only for the values \u200b\u200bof the indirect characteristic falling into the range from H MIN to H Max.

If the correlation coefficient R< 0, 7 или значение S T . H . M / R̅ ф > 0, 15, then monitoring and assessment of strength on dependence is not allowed.

Appendix J.
(mandatory)

Conditional Dependency Binding Method

G.1 The value of concrete strength, determined using the graded dependence mounted for concrete, differing from the subject, is multiplied by the coefficient of coincidence k s. The value of k C is calculated by the formula

where R OS I - the strength of concrete in the I-M region, determined by the separation method with the rolling or test of cores according to GOST 28570;

R COSP I is the strength of concrete in the I-M site, determined by any indirect method according to the graded dependence;

n - the number of test sections.

G.2 When calculating the coincidence coefficient, conditions must be observed:

The number of sections of tests taken into account when calculating the coincidence coefficient, N ≥ 3;

Each particular value of R OS I / R core should be at least 0, 7 and not more than 1, 3:

;

Each particular value of R OS I / R core I should differ from the average value of no more than 15%:

The values \u200b\u200bof R OS I / R COS I do not satisfy the conditions (w.2), (20), should not be taken into account when calculating the coefficient of coincidence K s.

Appointment of the number of sections of tests of prefabricated and monolithic structures

And.1 in accordance with GOST 18105 when monitoring the strength of concrete of prefabricated structures (vacation or gear), the number of controlled structures of each species takes at least 10% and at least 12 structures from the party. If the party consists of 12 constructions and less, conduct solid control. In this case, the number of areas should be at least:

1 per 4 m length of linear structures;

1 on 4 m 2 squares of flat designs.

And.2 In accordance with GOST 18105, when monolithic concerns monolithic structures are monitored at an intermediate age, non-destructive methods control at least one design of each type (column, wall, overlapping, rigl, etc.) from the controlled batch.

And.3 In accordance with GOST 18105, when monolithic concerns monolithic structures are monitored at design age, a continuous non-destructive testing of concrete strength of all designs of the controlled batch is carried out. At the same time, the number of test sections should be at least:

3 for each invapination for flat designs (wall, overlapping, foundation plate);

1 to 4 m lengths (or 3 on the capture) for each linear horizontal design (beam, riglels);

6 For each design - for linear vertical structures (column, pylon).

The total number of measurements for calculating the characteristics of the homogeneity of the concrete strength of the batch of structures should be at least 20.

And 4. The number of single measurements of concrete strength by mechanical methods of non-destructive testing on each site (the number of measurements on the site) is received by table 2.

Test results presentation table form

Name of structures (parties of structures), design class of concrete strength, concreting date or concrete age tested structures	Designation (1)	N plot according to the scheme or location in the axes (2)	Concrete strength, MPa		Concrete strength class (5)
			plot (3)	average (4)






(1) Brand, symbol and (or) Location of the design in the axes, construction zones, or parts of the monolithic and collection-monolithic design (capture), for which the concrete strength class is determined. (2) Total number and location of sites in accordance with 7.1.1. (3) Concrete strength plot in accordance with 7.1.5. (4) The average strength of the concrete structure, the design zone or part of the monolithic and collection-monolithic design with the number of areas that meet the requirements 7.1.1. (5) The actual strength of the concrete strength of the design or part of the monolithic and collecting-monolithic design according to items 7.3 - 7.5 GOST 18105, depending on the selected control scheme. Note - Presentation in the Class of "Concrete Strength" Count Evaluation values \u200b\u200bof the class or values \u200b\u200bof the required concrete strength for each site separately (Evaluation of the strength class in one section) is not permissible.

Concrete strength on compression is the main indicator that characterizes concrete.

There are two expressions of this indicator:

Concrete strength on compression is the main indicator that characterizes concrete. It is on him that the non-destructive testing of concrete strength in monolithic structures is focused. There are two expressions of this indicator:

Concrete class, b - This is the so-called cube strength (i.e., a compressible sample in the form of a cube), showing the maintained pressure in MPa. The share of the probability of destruction during the test of concrete on strength does not exceed 5 units of 100 test samples. Denoted by the Latin letter B and the number showing the strength in MPa. According to SNiP 2.03.01-84 "Concrete and reinforced concrete structures".
Concrete brand, m - This is the tensile strength of concrete for compression, kgf / cm². It is indicated by the Latin letter M and numbers from 50 to 1000. The maximum deviation that allows monitoring and assessment of concrete strength according to GOST 26633-91 "Concretes heavy and fine-grained - 13.5%.

Brand of concrete and class are determined after 28 days from the day of the fill, under normal conditions, or the calculation is carried out taking into account the coefficient (after 7-14 days, the material acquires 60-80% of the varying strength, after 28 days of about 100%, after 90 days -130% .). The ultrasonic method of non-destructive control of concrete is carried out, as a rule, in the intermediate and design age of reinforced concrete design.

The strength of concrete is influenced by a number of factors: cement activity, cement content, water ratio to cement by weight, quality of aggregates, mixing quality and degree of sealing, age and conditions of hardening concrete, re-vibration. The temperature and humidity of the medium has a great influence on the velocity of concrete. The conditionally normal is considered the medium with a temperature of 15-20 ° C and air humidity of 90-100%. With an increase in cement content in concrete, its strength grows to a certain limit. It is then grows slightly, the other properties of concrete deteriorate: the shrinkage increases, creep. Therefore, no more than 600 kg of cement is not recommended for 1 m³ of concrete.

Compliance of the brand of concrete (m) class (B) and compression strength

Brand concrete, m	Concrete class, b	Strength, MPa	Strength, kg / cm 2

Rocking methodit takes a special place in a number of non-destructive methods for determining concrete strength. Considered the non-destructive method, the separation method with the rocking in its essence is a destructive method, since the strength of the concrete is estimated in an effort necessary to destroy a small volume of concrete, which allows you to most accurately assess its actual strength. Therefore, this method is applied not only to determine the strength of the concrete of an unknown composition, but also can serve to build calibration dependencies for other non-destructive testing methods. This method is applied to heavy concrete and structural concrete on light aggregates in monolithic and precast concrete and reinforced concrete products, structures and structures and sets the method of testing concrete and determining its compression strength by local destruction of concrete when the special anchor device is separated from it. Such ultrasonic Method of Concrete Strength Allows you to determine the strength to compression for concrete in the range of strengths from 5.0 to 100.0 MPa. When developing the standard, materials are GOST 22690-88.

One of the most common and effective ways Non-destructive testing of the determination of concrete strength is the measurement of the sclerometer, or as it is also called the Schmidt hammer.

Concrete strength definition methods: Equipment used

With the help of the devices presented below, it is possible to test concrete to a non-destructive method. It allows you to more accurately predict physical characteristics Ready reinforced concrete structures, So - minimize losses construction organization And to protect the customer of work from all sorts of trouble.

Among other things, such a quality control of concrete allows components of concrete, the temperature of which dropped below 0ºС. Traditional methods Concrete Quality Control In Laboratory Conditions, it is not necessary to boast such convenience: I previously had to take a sample and check it at room temperature In laboratory conditions. Interesting modern solution Also, the contractors may not resort to the services of relevant organizations at each stage construction work. In turn, experts can independently come to the object and conduct an examination of the quality of concrete in accordance with the provisions of GOST. The equipment is compact enough and mobile, and the preparation of results takes a minimum of time.

Used equipment

Schmidt Hammer Original Schmidt Type N

Test products made of concrete using the Schmidt Schmidt's Schmidt Schmidt - the most common method of measurement method that does not destroy concrete in accordance with GOST 22690-2015

For each specific type of product tests from concrete, Proceq offers the appropriate hammer model.

Models of Schmidt hammers for test products of type Original Schmidt with different impact energies for testing materials of various types and sizes are available.

Our hammers N, NR, L and LR types are specifically designed to assess the quality and strength to compress concrete products with a range from 10 to 70 N / mm2 (from 1,450 to 10,52 pounds / square meters).

Models with built-in paper scrappers (LR and NR) are capable of automatically registering the rebound values \u200b\u200bon paper tape.

Schmidt Hammer Brochure Brochure Certificate

Pos-50mg4 "Skole" is intended for non-destructive testing of concrete strength by the ribs of ribs, separating with the rocking and separation of steel discs according to GOST 22690-2015.

Measuring the strength of concrete with the help of such equipment is allowed both on the erected projects and at the finished buildings. The device is indispensable in the construction sector, in the work of public utilities and restoration bureaus, periodically inspecting the integrity of buildings. The model received a non-volatile memory in which two hundred of the latest measurement results are preserved. They are marked with a brand of concrete and an accurate date of analysis, allowing experts to easily track the dynamics of changing key indicators.

Determining the strength of non-destructive testing mechanical methods. Determination of the strength of mechanical methods of non-destructive testing E.5 Terms of use of calibration dependence

1 area of \u200b\u200buse

2 Regulatory references

5 Measurement Means, Equipment and Tool

6 Test preparation

7 Testing

8 Processing and design results

Appendix A. (mandatory) Standard Test Scheme by Rockwing

Appendix B. (mandatory) Standard Test Scheme Rib Rib

Appendix B. (recommended) Conditioning dependence for the separation method with the crewing

Appendix G. (recommended) Graduation Dependence for Rib Range Method With a standard test diagram

Appendix D. (mandatory) Requirements for mechanical testing

Appendix J. (mandatory) Conditional Dependency Binding Method

Appendix K. (recommended) Test results presentation table form

1 area of \u200b\u200buse

2 Regulatory references

3 Terms and Definitions

4 General

5 Measurement Means, Equipment and Tool

6 Test preparation

7 Testing

Table 2 - Test Requirements Requirements

8 Processing and design results

Standard Test Scheme by Rockwing

Table A.1 - Anchor Device Parameters with Standard Test Scheme

Standard Test Scheme Rib Rib

Graduation dependence for the separation method with the rocking with the standard test diagram

Graduation dependence for the rib of ribs with a standard test diagram

Requirements for mechanical testing

Methods of establishing, adjusting and evaluating parameters of calibration dependencies

Conditional Dependency Binding Method

Appointment of the number of sections of tests of prefabricated and monolithic structures

Test results presentation table form

Concrete strength on compression is the main indicator that characterizes concrete.

There are two expressions of this indicator:

Compliance of the brand of concrete (m) class (B) and compression strength

Concrete strength definition methods: Equipment used

Used equipment

Appendix A.
(mandatory)
Standard Test Scheme by Rockwing

Appendix B.
(mandatory)
Standard Test Scheme Rib Rib

Appendix B.
(recommended)
Conditioning dependence for the separation method with the crewing

Appendix G.
(recommended)
Graduation Dependence for Rib Range Method
With a standard test diagram

Appendix D.
(mandatory)
Requirements for mechanical testing

Appendix J.
(mandatory)
Conditional Dependency Binding Method

Appendix K.
(recommended)
Test results presentation table form