Determination of concrete strength by elastic rebound method. Determining the strength of mechanical methods of non-destructive testing methods for determining concrete strength: used equipment
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)
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Short name of the country |
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Abbreviated name of the National Authority |
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Armenia |
Ministry of Economy of the Republic of Armenia |
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Belarus |
Gosstandart of the Republic of Belarus |
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Kazakhstan |
Gosstandart of the Republic of Kazakhstan |
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Kyrgyzstan |
Kyrgyzstandart |
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Moldova |
Moldova Standard |
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Russia |
Rosstandard. |
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Tajikistan |
Tajikstandard |
4 by the order of the Federal Agency for Technical Regulation and Metrology of September 25, 2015 No. 1378-ST Interstate Standard GOST 22690-2015 was enacted as a national standard of the Russian Federation from April 1, 2016.
5 This standard takes into account the main regulations in terms of the requirements for mechanical methods. non-destructive testing Concrete strength of the following European regional standards:
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 introduction - 2016-04-01
1 area of \u200b\u200buse
This standard applies to structural heavy, fine-grained, lightweight and straining concrete monolithic, prefabricated and assembled concrete 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, ribbling 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 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 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, thermal guns, etc.) to a depth of 50 mm to a temperature not lower than 0 ° C and are tested by 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
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Name method |
Total number |
Minimum |
Minimum |
Mining |
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Elastic rebound |
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Impact impulse |
||||
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Plastic deformation |
||||
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Rubbing ribs |
||||
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Foundation |
2 diameters |
|||
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Targeting with the creation of anchor sealingh.: |
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≥ 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 |
Anchor diameter |
Depth of embedding anchor devices, |
Permissible for anchor |
||
|
working h. |
full h " |
heavy |
easy |
||
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45 - 75 |
|||||
|
10 - 50 |
10 - 40 |
||||
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40 - 100 |
|||||
|
5 - 100 |
5 - 40 |
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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.
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Type anchor |
Range |
Anchor diameter |
The depth of embelling anchor |
The value of the coefficientm. 2 for concrete |
|
|
heavy |
easy |
||||
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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
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Name characteristics of devices |
Device characteristics for method |
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|
elastic |
shock |
plastic |
oterval |
rocking |
otervoy S. |
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Hardness of the drummer, brisk or an HRCE indenter, not less |
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Roughness of the contact part of the drummer or indenter, microns, not more |
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The diameter of the drummer or indenter, mm, not less |
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The thickness of the edges of the disk indenter, mm, not less |
||||||||||||||||||||||||||||||||||||||
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The angle of the conical indenter |
30 ° - 60 ° |
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The diameter of the imprint,% of the diameter of the indenter |
20 - 70 |
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Perpendicular admission when the load application at a height is 100 mm, mm |
||||||||||||||||||||||||||||||||||||||
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Energy impact, J, not less |
0,02 |
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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 Appendix J.
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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:
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1 per 4 m length of linear structures; 1 on 4 m 2 squares of flat designs. Appendix K.
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Name of structures |
Designation 1) |
Plot number according to the scheme |
Concrete strength, MPa |
Strength class |
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plot 3) |
average 4) |
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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) The average strength of concrete construction, 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. |
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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 |
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| 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.
State Standards of the SSR Union
Concrete heavy
Methods for determining the strength without disruption of mechanical devices
Official edition
State Committee of the USSR on the standards of Moscow
UDC 691.32: 620.17: 006.354 Group G19
State Standard of the SSR Union
Concrete heavy
General requirements for the methods of determining the strengthless destruction of mechanical devices
Concrete. General Requirements for Methods of NondestRUCTIVE STRENGTH DETERMINATION BY THE MECHANICAL DEVICES
Resolution State Committee Council of Ministers of the USSR on construction activities of August 22, 1977 No. 128 The deadline for administration is established
from 01.07. 1978
Failure to comply with the standard is prosecuted by law.
1. This standard applies to heavy concrete and establishes general requirements To the methods for determining its compression strength in products and structures of mechanical action to rebound, plastic deformation, the ribbling of the rib design and the separation.
Determination of concrete strength by the method of separation with the rocky - according to GOST 21243-75.
2. Concrete strength is determined by pre-established experimentally gradual dependencies between the strength of concrete samples, tested according to GOST 10180-78, and the indirect characteristics of the strength of concrete (rebound value, the size of the imprint, the string of the rib of construction, conditional voltage under the separation) of those installed non-destructive tests of those same samples.
3. To construct calibration dependencies, samples - Cubes, which meet the requirements of GOST 10180-78 and having dimensions, see:
15x15x15 - for rebound and plastic deformation methods;
20x20x20 - the ribs of the rib of construction and separation.
Edition Official Reprint is prohibited
Reprint. November 1981
© Standards Publishing House, 1982
Op. 10 GOST 22690.0-77
The shape of the concrete strength of concrete in structures
1. Test object ________
2. Test date _
3. The name of the design (for prefabricated structures - Mark, a series of work drawings) _ "_
4. View of concrete and its design strength _
5. Test method, device, pulp parameters (impact energy, indenter size or disc area, stall material, etc.).
6. Test results (see table)
P. 2 GOST 22690.0-77
The gradding dependence for monitoring the strength of the concrete of one brand is set by the test results of at least 20 episodes, each of which consists of three twin samples. Samples must have the same composition, as well as the duration and conditions of hardening with concrete used for the manufacture of controlled structures. Made samples for two weeks (no less) in different shifts. To obtain calibration dependence in a wider range of strength changes, up to 40% of samples should be made with a deviation of cement-growing ratio to ± 0.4. The rejection of the abnormal test results of the samples is carried out at mandatory annex 1.
4. When monitoring the strength of concrete in the erected structures from various sections, at least 20 cubic samples are cut out, while the test result of one sample is equal to the test result of the sample series.
It is allowed to establish a calibration dependence of cubes with a side of at least 7.07 cm or cores with a diameter of at least 7.14 cm. In this case, the following test order should be. On the construction site spend non-destructive tests, then cut the sample and test it for compression. The boundaries of the test zones of the non-destructive method and cutting of the sample should be from each other at a distance of no more than 100 mm.
5. Graduation dependence should be installed at least twice a year, as well as when the materials applied to the preparation of concrete, and the manufacturing technology of structures.
The method of calculating the equation of the calibration dependence is given in the recommended Appendix 2, and an example of its construction is in the reference application 3.
6. Evaluation of the error of graduation dependence is carried out according to GOST 17624-78.
7. Experts of specialized research organizations may conduct an indicative assessment of concrete strength, using a graded dependence established for concrete, differing from the test (according to the composition, age and experimental conditions), with clarification of it according to the results of a test of at least three cut samples or three tests. Method of separation with the parking lot according to GOST 21243-75.
8. Devices seized to determine the strength of concrete should undergo a departmental verification at least once every two years, as well as after each repair or replacement of parts. The results of the verification must be decorated with the act.
9. Plots for the test of concrete should be chosen on the surfaces of the design in contact with the manufacture with a metal, stringent wooden or other smooth formwork. EU-
GOST 22690.0-77 p. 3.
whether the surface of the design has a finish, then it must be removed before testing.
10. Strength should be determined at a positive temperature of concrete.
11. Concrete strength on the construction site is determined by the average value of the indirect characteristic of concrete strength in this area, using the established calibration dependence, taking into account the rejection of the abnormal results produced by the mandatory annex 1.
The test results should be logged into a magazine, the form of which is provided in the recommended Annex 4.
12. Control and assessment of concrete strength on compression and its homogeneity in structures - according to GOST 18105.0-80-GOST 18105.2-80.
P. 4 GOST 22690.0-77
Appendix 1 Mandatory
Rules for rejection of abnormal test results
1. The rejection of the abnormal test results (A *) is carried out with the number of results at least 3 by formula (1):
a) for the result of the test on the press of one sample in the series;
b) for a single test result by non-destructive method in one sample;
c) for a single test of testing non-destructive method n-a Plot design.
2. The result of the test recognize the abnormal and not taken into account when calculating
if the value of T, determined by formula (1), exceeds the permissible value of the TC, shown in Table. one. _
where a - average strength concrete in a series of samples, the average test result by the non-destructive method of one sample or construction site;
5 is the average quadratic deviation determined by calculating the calibration dependence by formula (2).
Table 1
Meaning T I.
where D is the coefficient taken in Table. 2;
XI Shah and XI Min - maximum and minimum test results in a series of samples or in a separate sample;
N is the number of series (case A) or the number of individual samples (case b) used in constructing calibration dependence.
When evaluating the abnormality of individual test results in areas of structures, the value s is taken equal to the calculated for individual samples when constructing calibration dependence.
table 2
Coefficient value D.
GOST 22690.0-77 p. five
Method of calculating the equation of calibration dependence "indirect characteristic - strength"
Equation of the "indirect characteristic - strength" adoption:
when the range of concrete strength is up to 200 kgf / cm 2 - linear:
when the range of concrete strength is over 200 kgf / cm 2 exponential:
R - b 0 - / b, n. (2)
Factors of 0; Ai h is calculated by formulas.
# 0 - R- (I \\ '//, * (3)
"\u003d '-H? -Z-: (4)
2 (HI-77) (in ri-uir)
| B n \u003d c ^ - b ". |
The average values \u200b\u200bof the strength of R and indirect characteristics I needed to determine these coefficients are calculated by formulas:
* \u003d Чг:< 7 >
In /? - \u003d * "" s -; (nine)
Ri and Hi values \u200b\u200bare respectively values \u200b\u200bof the strengths and indirect characteristics for individual series of three samples (or one sample), and N is the number of series (or individual samples) used to build calibration dependence.
It is allowed to use the level (1) level (or graphic construct) of calibration dependence in cases where the error and efficiency coefficient of the dependence, determined according to GOST 17624-78 are in the allowed limits.
The estimate of the error of graduation dependence is carried out according to GOST
P. 6 GOST 22690.0-77
Appendix $ reference
Examples of constructing calibration dependence and rejection of the abnormal test results
Construction of calibration dependence
Concrete strength M250 design brand is controlled by the rebound method by the KM device. To build a relationship between the magnitude of the rebound (s) and the strength to compress control samples on the press (/?) 29 series of samples were tested (A g * \u003d 29). The average results for each series are given in Table. !.
Table 1
| Number series |
H, divisions |
Serin number |
W, division |
R, kgf / cm » |
|
Since the range of measuring the strength of concrete 330-169 "\u003d" 170 kgf / cm * is less than 200 kgf / cm *, then in accordance with the method described in the recommended Annex 2, the equation of the desired dependence is taken linear: * \u003d oo + a g I. equation coefficients Calculate, substituting the data of Table V_Foriolez (3) and (4) of the recommended application 2.
I am * 252.9 kgf / cm 3; h "18.24; "36.76; CO - 417.79.
The calibration dependence "the magnitude of the rebound - strength" is expressed by equation # "36.76 I-413.
The dependency graph is given in the drawing.
GOST 22690.0-77 p. one
Dependence "indirect characteristic (rebound value) - strength"
R, kgf / cm 1
Calculation of medium quadratic deviations for strength in a series of 3 samples and by the magnitude of the rebound in 5 measurements on one sample.
When constructing calibration dependence (see example i), 29 series of 3 samples were tested. In each sample, the magnitude of the rebound was determined at 5 points. The sample from the test results table is given in Table. 2.
table 2
| Series number 1. |
Sample numbers; | |
Numbers Test Points |
/? , Kgosl1 * |
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Page, 8 GOST 22690.0-77
Continued
| Rooms seried 1. |
Sample numbers / |
Numbers Test Points |
RJ T KTS / CM 3 |
f U Max ** min " |
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| 16.9 17.5 18.8 19.0 18.2 cf. 18,1 |
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The average quadratic deviation of concrete strength in the sample series, defined by formula (2) and Table. 2, will be
S- --- - \u003d 18 KIX / CM L.
By the same formula, the average quadratic deviation of the height of the rebound on the device KM in samples is calculated
4,1+2,9+2,5+3,3+2,1+1,9+...
YTSH-- "" 5<е *’
In the second series (see example 2) the strength of the third sample differs significantly from the middle in the series. To verify the abnormality of this result by the formula (1) of the mandatory application 1 calculate the magnitude
GOST 22690.0-77 p. nine
what is less than the value defined by table T to -1.74 for three samples in the series. Consequently, the result of 252 kgf / cm 2 should not be excluded when determining concrete strength in the second series of samples.
In the first sample of the first series (see example 2) the result of 16.0 cases. It differs significantly from the average sample value. To verify the abnormality of this result by the formula (1) of the mandatory application 1 calculate the magnitude
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