GBJ 129-1990 Standard for test methods of basic mechanical properties of masonry
Some standard content:
Engineering Construction Standards Full-text Information System
National Standard of the People's Republic of China
Standard for Test Methods of Basic Mechanical Properties of Masonry GBJ
129-90
Engineering Construction Standards Full-text Information System
W Engineering Construction Standards Full-text Information System
National Standard of the People's Republic of China
Standard for Test Methods of Basic Mechanical Properties of Masonry GBJ129-90
Editor Department: Sichuan Provincial Construction Committee
Approval Department: Ministry of Construction of the People's Republic of China Effective Date: January 1, 1990
Engineering Construction Standards Full-text Information System|| tt||Engineering Construction Standard Full Text Information System
Notice on the Release of the National Standard "Standard for Test Methods of Basic Mechanical Properties of Masonry"
(90)Jianbiaozi No. 177
According to the notice of the former State Construction Commission (81) Jianfashezi No. 546 and the State Planning Commission Jizong [1984] No. 305, the "Code for Design of Masonry Structures" was revised. Later, under the arrangement of the former Standard and Norms Bureau of the State Planning Commission, the mechanical properties test methods in the code were supplemented and improved, and listed as a separate standard, namely "Standard for Test Methods of Basic Mechanical Properties of Masonry", which was formulated by Sichuan Provincial Academy of Building Sciences in conjunction with relevant units and has been reviewed by relevant departments. The "Standard for Test Methods of Basic Mechanical Properties of Masonry" (G-BJ129-
90) is now approved as a national standard and will be implemented from January 1, 1991. This standard is managed by the Sichuan Provincial Construction Commission, and its specific interpretation and other work are the responsibility of the Sichuan Provincial Academy of Building Sciences. The publication and distribution is organized by the Standard and Norms Research Institute of the Ministry of Construction.
Ministry of Construction
April 19, 1990
Engineering 2 Construction Standard Full Text Information System
Engineering Construction Standard Full Text Information System
Preparation Instructions
This standard is based on the notice of the former State Construction Commission (81) Jianfa Shezi No. (546) and the State Planning Commission Jizongzi [1984] No. 305, which amended the "Code for Design of Masonry Structures". Later, under the arrangement of the former Standard and Norms Bureau of the State Planning Commission, the mechanical properties test methods in the code were supplemented and improved, and listed as a separate standard. It was jointly prepared by the Sichuan Provincial Academy of Building Sciences and relevant units. During the preparation of this standard, the standard preparation team conducted extensive investigations and studies, carefully summarized my country's practical experience in the construction, design and production of masonry projects, referred to relevant international standards and advanced foreign standards, carried out scientific research and test verification work on major technical issues, and widely solicited opinions from relevant units across the country. Finally, our commission reviewed and finalized it together with relevant departments. The main contents of this standard include: basic provisions for specimen masonry and testing, masonry compression test method, masonry shear test method and masonry bending tensile test method, etc. In view of the fact that this standard is compiled for the first time, during the implementation process, all units are requested to combine the actual situation, carefully summarize the experience, and pay attention to accumulating data. If any modification or supplement is found, please send your opinions and relevant materials to Sichuan Academy of Building Science (Liangjiaxiang, Chengdu, Sichuan Province) for reference in future revisions.
Sichuan Provincial Construction Committee
April 1990
Engineering Construction Standards Full-text Information System
Engineering Construction Standards Full-text Information System
Chapter 1
General Provisions·
Chapter 2
Basic Provisions for Specimen Masonry and Testing.
Test Method for Masonry Compressive Strength·
Chapter 3
Section 1: Specimens
Section 2 Test Procedures
Section 3
Result Calculation
Chapter 4||tt ||Chapter 5
..a...
Test method for shear strength of masonry along the through seam section·Test method for bending tensile strength of brick masonry
Terms used in this standard
Additional explanation·
Engineering 4 Construction Standard Full Text Information System
Engineering Construction Standard Full Text Information System
Chapter 1 General
Article 1.0.1 In order to unify the test methods for the basic mechanical properties of masonry, make the test data accurate, reliable and comparable, and ensure the construction quality of masonry engineering, this standard is specially formulated.
Article 1.0.2
This standard is applicable to the mechanical property test and inspection of masonry in industrial and civil buildings.
Article 1.0.3 The block materials used in the masonry specimens of this standard are bricks, blocks, stone and rough stone. The mechanical properties of the block materials should be inspected according to the current relevant national standards.
Article 1.0.4
In addition to complying with the provisions of this standard, the test of the basic mechanical properties of masonry shall also comply with the relevant provisions of the current national standards. Engineering Construction Standard Full-text Information System
Engineering Construction Standard Full-text Information System
Chapter 2 Basic Provisions for Specimen Masonry and Testing Article 2.0.1 Masonry tests can be divided into two categories according to the purpose of the test: research tests and inspection tests.
The number of test specimens in research tests and the number of test specimens in each group shall be determined according to special test designs.
The number of test specimens in inspection tests and the number of test specimens in each group shall be specified by the testing unit. However, under the same conditions, the number of test specimens in each group shall not be less than 3 for compression tests and shall not be less than 6 for shear and bending tests. Article 2.0.2 The laying of masonry specimens shall comply with the provisions of the current national standard "Code for Construction and Acceptance of Masonry Engineering" and the following requirements: 1. For specimens of the same grade of mortar or the same comparison group, a bricklayer with medium technical level shall lay them in a layered flow operation method, and each plate of mortar shall be evenly used for each specimen; for masonry specimens to inspect construction quality, they shall be laid on site.
2. After the shear or bending test specimens are laid, four layers of bricks or one layer of blocks shall be pressed flat on top of them immediately, and the pressing time shall not be less than 14 days. 3. A group of mortar specimens shall be made for each plate of mortar, and the number of specimens in each group shall not be less than 6. However, for masonry specimens of the same grade and type of mortar, the number of mortar specimen groups shall not be less than two. If the mortar specimen strength is required to control the curing time of the masonry specimen, the number of groups should be increased by 1 to 2 groups.
Fourth, the body specimens and mortar specimens shall be tested at the same time after curing for 28 days under natural conditions indoors. When the average temperature of the day is lower than 16℃, the curing time shall be appropriately extended.
Five, during the construction of masonry specimens, the mortar fullness shall be checked at any time. When checking after the test, for compression specimens, 3 pieces shall be selected from each group, and 3 blocks shall be checked for each piece; for shear or bending specimens, each failure section shall be checked. Engineering Construction Standard Full-text Information System
W.bzsoso.coI Engineering Construction Standard Full-text Information System
When the test results of the basic mechanical properties of masonry need to be expressed by statistical indicators in Article 2.0.3
, they shall be calculated according to the following formula. When the number of specimens is small, only the mean value shall be calculated.
, mean: mz=
2. Standard deviation, 8=
12(a;-m.)
3. Coefficient of variation (in percentage):
8==×100%
Wherein xi——measured value of specimen strength (N/mm2); n
——number of masonry specimens in a group.
(2.0.3—1)Www.bzxZ.net
(2.0.3-2)
(2.0.3—3)
Article 2.0.4 The equipment such as the loading frame and load distribution beam used in the test shall have sufficient strength and rigidity. The relative error of the indication of its measuring instrument shall be 2%. Article 2.0.5 Safety measures shall be taken to ensure personal safety and prevent instrument damage during the masonry and testing of the specimens.
Engineering Construction Standard Full Text Information System
Engineering Construction Standard Full Text Information System
Chapter 3 Masonry Compressive Strength Test Method
Section 1 Test Pieces
Article 3.1.1 For ordinary bricks with an outer dimension of 240mm×115mm×53mm, the size of the masonry compressive test piece (thickness×width×height) should be 240mmX370mmX720mm. The cross-sectional dimensions of masonry compressive test pieces of non-ordinary bricks can be slightly adjusted. However, the height should be determined according to the height-to-thickness ratio β equal to 3. The allowable error in the thickness and width of the test piece should be ±5mm.
The thickness of the masonry compressive test piece of medium and small blocks should be the thickness of the block; the width should be the length of the main specification block; and the height should be the height of three layers of blocks plus the thickness of the mortar joint. The middle layer of blocks should have a vertical mortar joint (Figure 3.1.1). The thickness of the rubble stone masonry compression test piece should be 200~250mm, and the width should be 350~400mm; the thickness of the rough stone masonry compression test piece should be 400mm, and the width should be 700~800mm; the height of both types of test pieces should be determined according to the height-to-thickness ratio β equal to 3. The middle layer of stone blocks of the rubble stone masonry test piece should have a vertical mortar joint. All types of masonry compression test pieces should be built on a rigid pad with a hook or a steel pad with a thickness of not less than 10mm. The pad should be leveled; the top of the specimen should be leveled with 1:3 cement mortar with a thickness of 10mm, and its flatness should be checked with a level ruler.
Section 2 Test Steps
Article 3.2.1 The preparation work before the body compression test shall comply with the following engineering construction standard full-text information system
W engineering construction standard full-text information system
Regulations:
1. The specimen should be inspected for appearance, and records should be made when there are signs of collision or other damage; when the specimen is seriously damaged, the specimen should be discarded. 2. The vertical center line should be drawn on the four sides of the specimen. 3. The width and thickness of the specimen should be measured at 1/4, 1/2 and 3/4 of the specimen height, respectively, and the measurement accuracy should be 1mm. The average value should be used for the measurement result. The height of the specimen should be determined based on the top surface of the pad and measured to the top surface of the leveling layer. 4. When installing the test piece, the test piece should be hoisted first, and the sundries stuck under the pad should be removed, and then placed on the lower pressure plate of the testing machine. When the upper and lower pressure plates of the testing machine are smaller than the cross-sectional size of the test piece, a rigid pad should be added: when the contact between the pressure-bearing surface of the test piece and the pressure plate of the testing machine is uneven and tight, it should be leveled. When the test piece is in place, the vertical center line of the four sides of the test piece should be aligned with the axis of the testing machine.
5. When installing the instrument, when measuring the axial deformation value of the test piece, a micrometer or other instrument for measuring deformation should be installed on the vertical center line of the two wide sides of the test piece through the table seat adhered to the surface of the test piece. The distance between the measuring points should be 1/3 of the height of the test piece, and a multiple of the thickness of a block plus the thickness of a mortar seam. When measuring the lateral deformation of the test piece, the instrument should be installed on the horizontal center line of the wide side, and the distance between the measuring point and the edge of the test piece should not be less than 50mm.
Sixth, when applying 5% of the estimated failure load to the specimen, the sensitivity of the instrument and the firmness of the installation should be checked.
Article 3.2.2 For specimens that do not need to measure deformation values, the geometric centering and graded load application method can be used. The load of each level should be 10% of the estimated failure load value, and should be evenly applied within 1 to 1.5 minutes; the next level of load should be applied after 1 to 2 minutes of constant load. When applying the load, the specimen shall not be impacted. After the load is applied to 80% of the estimated failure load value, the load should be continuously applied at the original loading speed until the specimen is destroyed. When the cracks of the specimen expand and increase sharply, and the dynamometer pointer of the testing machine retreats significantly, it should be determined that the specimen has lost its bearing capacity and reached a state of destruction. Its maximum load reading should be the failure load value of the specimen.
Article 3.2.3 For specimens that need to measure deformation values and determine the elastic modulus of masonry, the physical centering and graded load application method should be adopted. Within the range of 5% to 20% of the estimated failure load value, the preloading should be repeated 3 to 5 times. The relative error of the axial deformation values of the two wide sides should not exceed 10%. If it exceeds, the specimen position should be readjusted or the specimen should be leveled. After preloading, the load should be unloaded and the sub-meter pointer should be adjusted to zero. The load should be applied step by step according to the load application method specified in Article 3.2.2 of this standard, and the deformation value should be measured and recorded at the same time. When the load reaches 80% of the estimated failure load value, the instrument should be removed, and then the specimen should be continuously loaded until it fails.
Note: The estimated failure load value can be determined by tentative tests or calculated according to the formula of the current national standard "Code for Design of Masonry Structures". Article 3.2.4 During the test, the first hairline crack under load should be observed and captured, and the initial crack load value should be recorded. For specimens equipped with deformation measuring instruments, cracks that may appear when the deformation value suddenly increases should be observed. When the load increases step by step, the development of cracks should be observed and described. After the specimen is destroyed, a crack diagram should be drawn and the destruction characteristics should be recorded immediately.
Section 3 Result Calculation
Article 3.3.1 The compressive strength fcm of a single specimen should be calculated according to the following formula, and the calculation result should be accurate to 0.1N/mm2: fen N
Where fcm—compressive strength of specimen (N/mm2); N—compressive failure load value of specimen (N); (3.3.1)
A—cross-sectional area of specimen (mm), calculated according to the average width and average thickness of the specimen measured in Article 3.2.1 of this standard. Article 3.3.2 The measured values of elastic modulus E and Poisson's ratio of a single specimen shall be calculated according to the following steps:
1. The axial strain e and transverse strain &tr under step-by-step loads shall be calculated according to the following formulas:
(3.3.2-1)
etr = r
Engineering Construction Standard Full-text Information System
(3.3.2-2)
Engineering Construction Standard Full-text Information System
e——Axial strain value under step-by-step load
eu—Transverse strain value under step-by-step load; 1, lr——Axial and transverse deformation values under step-by-step load (mm), respectively;
lltr—The distance between axial and transverse measuring points (mm), respectively. 2. The stress under the step-by-step load shall be calculated as follows: N
Where g is the stress value under the step-by-step load (N/mm2); N is the step-by-step load value borne by the specimen (N). (3.3.2-3)
3. The relationship curve between stress and axial strain shall be drawn with g as the ordinate and 8 as the abscissa. According to the curve, the secant modulus when the stress α is equal to 0.4f. m shall be taken as the elastic modulus of the specimen and shall be calculated as follows: E
Where E is the elastic modulus of the specimen (N/mm2); 8a4 is the axial strain value corresponding to 0.4f. 4. The Poisson's ratio corresponding to the step-by-step stress shall be calculated as follows: V=et
(3.3.2-4)
(3.3.2-5)
The relationship curve between stress and Poisson's ratio shall be drawn with stress as the ordinate and Poisson's ratio as the abscissa. According to the curve, the Poisson's ratio o.4 when the stress α is equal to 0.4f. should be taken as the Poisson's ratio of the specimen.
Article 3.3.3
When the cross-sectional dimensions of the brick masonry do not meet the requirements of Article 3.1.1 of this standard, the compressive strength 0.4f. m value should be multiplied by the correction factor according to the test results. The correction factor Φ should be calculated according to the following formula:
Where——correction factor;
8—cross-sectional perimeter of the specimen (mm).
Article 3.3.4When the height-to-thickness ratio β of the medium-sized masonry specimen is greater than 3, the Engineering Construction Standard Full-text Information System
W1. The preparation work before the compression test of a strip shall comply with the following provisions of the Engineering Construction Standard Full-text Information System
W Engineering Construction Standard Full-text Information System
:
1. The specimen shall be inspected for appearance, and records shall be made when there are signs of collision or other damage; when the specimen is severely damaged, the specimen shall be discarded. 2. The vertical center line shall be drawn on the four sides of the specimen. 3. The width and thickness of the specimen shall be measured at 1/4, 1/2 and 3/4 of the specimen height, respectively, and the measurement accuracy shall be 1mm. The average value shall be used as the measurement result. The height of the specimen shall be determined based on the top surface of the pad and measured to the top surface of the leveling layer. 4. When installing the specimen, the specimen shall be hoisted first, the debris stuck under the pad shall be removed, and then placed on the lower pressure plate of the testing machine. When the upper and lower pressure plates of the testing machine are smaller than the cross-sectional size of the specimen, a rigid pad should be added: when the contact between the pressure-bearing surface of the specimen and the pressure plate of the testing machine is uneven and tight, it should be leveled. When the specimen is in place, the vertical center line of the four sides of the specimen should be aligned with the axis of the testing machine.
V. Installation of instruments: When measuring the axial deformation value of the specimen, a micrometer or other instrument for measuring deformation should be installed on the vertical center line of the two wide sides of the specimen through the table seat adhered to the surface of the specimen. The distance between the measuring points should be 1/3 of the specimen height and a multiple of the thickness of a block plus the thickness of a mortar joint. When measuring the lateral deformation of the specimen, the instrument should be installed on the horizontal center line of the wide side, and the distance between the measuring point and the edge of the specimen should not be less than 50mm.
VI. When applying 5% of the estimated failure load to the specimen, the sensitivity of the instrument and the firmness of the installation should be checked.
Article 3.2.2 For specimens that do not need to measure deformation values, the geometric centering and graded load application method can be used. The load of each level should be 10% of the estimated failure load value, and should be evenly applied within 1 to 1.5 minutes; the next level of load should be applied after 1 to 2 minutes of constant load. When applying the load, the specimen shall not be impacted. After the load is applied to 80% of the estimated failure load value, the load should be continuously applied at the original loading speed until the specimen is destroyed. When the cracks of the specimen expand and increase sharply, and the dynamometer pointer of the testing machine retreats significantly, it should be determined that the specimen has lost its bearing capacity and reached a state of destruction. Its maximum load reading should be the failure load value of the specimen.
Article 3.2.3 For specimens that need to measure deformation values and determine the elastic modulus of masonry, the physical centering and graded load application method should be adopted. Within the range of 5% to 20% of the estimated failure load value, the preloading should be repeated 3 to 5 times. The relative error of the axial deformation values of the two wide sides should not exceed 10%. If it exceeds, the specimen position should be readjusted or the specimen should be leveled. After preloading, the load should be unloaded and the sub-meter pointer should be adjusted to zero. The load should be applied step by step according to the load application method specified in Article 3.2.2 of this standard, and the deformation value should be measured and recorded at the same time. When the load reaches 80% of the estimated failure load value, the instrument should be removed, and then the specimen should be continuously loaded until it fails.
Note: The estimated failure load value can be determined by tentative tests or calculated according to the formula of the current national standard "Code for Design of Masonry Structures". Article 3.2.4 During the test, the first hairline crack under load should be observed and captured, and the initial crack load value should be recorded. For specimens equipped with deformation measuring instruments, cracks that may appear when the deformation value suddenly increases should be observed. When the load increases step by step, the development of cracks should be observed and described. After the specimen is destroyed, a crack diagram should be drawn and the destruction characteristics should be recorded immediately.
Section 3 Result Calculation
Article 3.3.1 The compressive strength fcm of a single specimen should be calculated according to the following formula, and the calculation result should be accurate to 0.1N/mm2: fen N
Where fcm—compressive strength of specimen (N/mm2); N—compressive failure load value of specimen (N); (3.3.1)
A—cross-sectional area of specimen (mm), calculated according to the average width and average thickness of the specimen measured in Article 3.2.1 of this standard. Article 3.3.2 The measured values of elastic modulus E and Poisson's ratio of a single specimen shall be calculated according to the following steps:
1. The axial strain e and transverse strain &tr under step-by-step loads shall be calculated according to the following formulas:
(3.3.2-1)
etr = r
Engineering Construction Standard Full-text Information System
(3.3.2-2)
Engineering Construction Standard Full-text Information System
e——Axial strain value under step-by-step load
eu—Transverse strain value under step-by-step load; 1, lr——Axial and transverse deformation values under step-by-step load (mm), respectively;
lltr—The distance between axial and transverse measuring points (mm), respectively. 2. The stress under the step-by-step load shall be calculated as follows: N
Where g is the stress value under the step-by-step load (N/mm2); N is the step-by-step load value borne by the specimen (N). (3.3.2-3)
3. The relationship curve between stress and axial strain shall be drawn with g as the ordinate and 8 as the abscissa. According to the curve, the secant modulus when the stress α is equal to 0.4f. m shall be taken as the elastic modulus of the specimen and shall be calculated as follows: E
Where E is the elastic modulus of the specimen (N/mm2); 8a4 is the axial strain value corresponding to 0.4f. 4. The Poisson's ratio corresponding to the step-by-step stress shall be calculated as follows: V=et
(3.3.2-4)
(3.3.2-5)
The relationship curve between stress and Poisson's ratio shall be drawn with stress as the ordinate and Poisson's ratio as the abscissa. According to the curve, the Poisson's ratio o.4 when the stress α is equal to 0.4f. should be taken as the Poisson's ratio of the specimen.
Article 3.3.3
When the cross-sectional dimensions of the brick masonry do not meet the requirements of Article 3.1.1 of this standard, the compressive strength 0.4f. m value should be multiplied by the correction factor according to the test results. The correction factor Φ should be calculated according to the following formula:
Where——correction factor;
8—cross-sectional perimeter of the specimen (mm).
Article 3.3.4When the height-to-thickness ratio β of the medium-sized masonry specimen is greater than 3, the Engineering Construction Standard Full-text Information System
W1. The preparation work before the compression test of a strip shall comply with the following provisions of the Engineering Construction Standard Full-text Information System
W Engineering Construction Standard Full-text Information System
:
1. The specimen shall be inspected for appearance, and records shall be made when there are signs of collision or other damage; when the specimen is severely damaged, the specimen shall be discarded. 2. The vertical center line shall be drawn on the four sides of the specimen. 3. The width and thickness of the specimen shall be measured at 1/4, 1/2 and 3/4 of the specimen height, respectively, and the measurement accuracy shall be 1mm. The average value shall be used as the measurement result. The height of the specimen shall be determined based on the top surface of the pad and measured to the top surface of the leveling layer. 4. When installing the specimen, the specimen shall be hoisted first, the debris stuck under the pad shall be removed, and then placed on the lower pressure plate of the testing machine. When the upper and lower pressure plates of the testing machine are smaller than the cross-sectional size of the specimen, a rigid pad should be added: when the contact between the pressure-bearing surface of the specimen and the pressure plate of the testing machine is uneven and tight, it should be leveled. When the specimen is in place, the vertical center line of the four sides of the specimen should be aligned with the axis of the testing machine.
V. Installation of instruments: When measuring the axial deformation value of the specimen, a micrometer or other instrument for measuring deformation should be installed on the vertical center line of the two wide sides of the specimen through the table seat adhered to the surface of the specimen. The distance between the measuring points should be 1/3 of the specimen height and a multiple of the thickness of a block plus the thickness of a mortar joint. When measuring the lateral deformation of the specimen, the instrument should be installed on the horizontal center line of the wide side, and the distance between the measuring point and the edge of the specimen should not be less than 50mm.
VI. When applying 5% of the estimated failure load to the specimen, the sensitivity of the instrument and the firmness of the installation should be checked.
Article 3.2.2 For specimens that do not need to measure deformation values, the geometric centering and graded load application method can be used. The load of each level should be 10% of the estimated failure load value, and should be evenly applied within 1 to 1.5 minutes; the next level of load should be applied after 1 to 2 minutes of constant load. When applying the load, the specimen shall not be impacted. After the load is applied to 80% of the estimated failure load value, the load should be continuously applied at the original loading speed until the specimen is destroyed. When the cracks of the specimen expand and increase sharply, and the dynamometer pointer of the testing machine retreats significantly, it should be determined that the specimen has lost its bearing capacity and reached a state of destruction. Its maximum load reading should be the failure load value of the specimen.
Article 3.2.3 For specimens that need to measure deformation values and determine the elastic modulus of masonry, the physical centering and graded load application method should be adopted. Within the range of 5% to 20% of the estimated failure load value, the preloading should be repeated 3 to 5 times. The relative error of the axial deformation values of the two wide sides should not exceed 10%. If it exceeds, the specimen position should be readjusted or the specimen should be leveled. After preloading, the load should be unloaded and the sub-meter pointer should be adjusted to zero. The load should be applied step by step according to the load application method specified in Article 3.2.2 of this standard, and the deformation value should be measured and recorded at the same time. When the load reaches 80% of the estimated failure load value, the instrument should be removed, and then the specimen should be continuously loaded until it fails.
Note: The estimated failure load value can be determined by tentative tests or calculated according to the formula of the current national standard "Code for Design of Masonry Structures". Article 3.2.4 During the test, the first hairline crack under load should be observed and captured, and the initial crack load value should be recorded. For specimens equipped with deformation measuring instruments, cracks that may appear when the deformation value suddenly increases should be observed. When the load increases step by step, the development of cracks should be observed and described. After the specimen is destroyed, a crack diagram should be drawn and the destruction characteristics should be recorded immediately.
Section 3 Result Calculation
Article 3.3.1 The compressive strength fcm of a single specimen should be calculated according to the following formula, and the calculation result should be accurate to 0.1N/mm2: fen N
Where fcm—compressive strength of specimen (N/mm2); N—compressive failure load value of specimen (N); (3.3.1)
A—cross-sectional area of specimen (mm), calculated according to the average width and average thickness of the specimen measured in Article 3.2.1 of this standard. Article 3.3.2 The measured values of elastic modulus E and Poisson's ratio of a single specimen shall be calculated according to the following steps:
1. The axial strain e and transverse strain &tr under step-by-step loads shall be calculated according to the following formulas:
(3.3.2-1)
etr = r
Engineering Construction Standard Full-text Information System
(3.3.2-2)
Engineering Construction Standard Full-text Information System
e——Axial strain value under step-by-step load
eu—Transverse strain value under step-by-step load; 1, lr——Axial and transverse deformation values under step-by-step load (mm), respectively;
lltr—The distance between axial and transverse measuring points (mm), respectively. 2. The stress under the step-by-step load shall be calculated as follows: N
Where g is the stress value under the step-by-step load (N/mm2); N is the step-by-step load value borne by the specimen (N). (3.3.2-3)
3. The relationship curve between stress and axial strain shall be drawn with g as the ordinate and 8 as the abscissa. According to the curve, the secant modulus when the stress α is equal to 0.4f. m shall be taken as the elastic modulus of the specimen and shall be calculated as follows: E
Where E is the elastic modulus of the specimen (N/mm2); 8a4 is the axial strain value corresponding to 0.4f. 4. The Poisson's ratio corresponding to the step-by-step stress shall be calculated as follows: V=et
(3.3.2-4)
(3.3.2-5)
The relationship curve between stress and Poisson's ratio shall be drawn with stress as the ordinate and Poisson's ratio as the abscissa. According to the curve, the Poisson's ratio o.4 when the stress α is equal to 0.4f. should be taken as the Poisson's ratio of the specimen.
Article 3.3.3
When the cross-sectional dimensions of the brick masonry do not meet the requirements of Article 3.1.1 of this standard, the compressive strength 0.4f. m value should be multiplied by the correction factor according to the test results. The correction factor Φ should be calculated according to the following formula:
Where——correction factor;
8—cross-sectional perimeter of the specimen (mm).
Article 3.3.4When the height-to-thickness ratio β of the medium-sized masonry specimen is greater than 3, the Engineering Construction Standard Full-text Information System
W1. Calculate the average width and average thickness of the specimen measured. Article 3.3.2 The elastic modulus E value and the measured value of Poisson's ratio of a single specimen shall be calculated according to the following steps:
1. The axial strain e and transverse strain &tr under step-by-step loads shall be calculated according to the following formulas:
(3.3.2-1)
etr = r
Engineering Construction Standard Full-text Information System
(3.3.2-2)
Engineering Construction Standard Full-text Information System
e——Axial strain value under step-by-step load
eu—Transverse strain value under step-by-step load; 1, lr——Axial and transverse deformation values under step-by-step load (mm);
lltr—The distance between axial and transverse measuring points (mm). 2. The stress under the step-by-step load shall be calculated as follows: N
Where g is the stress value under the step-by-step load (N/mm2); N is the step-by-step load value borne by the specimen (N). (3.3.2-3)
3. The relationship curve between stress and axial strain shall be drawn with g as the ordinate and 8 as the abscissa. According to the curve, the secant modulus when the stress α is equal to 0.4f. m shall be taken as the elastic modulus of the specimen and shall be calculated as follows: E
Where E is the elastic modulus of the specimen (N/mm2); 8a4 is the axial strain value corresponding to 0.4f. 4. The Poisson's ratio corresponding to the step-by-step stress shall be calculated as follows: V=et
(3.3.2-4)
(3.3.2-5)
The relationship curve between stress and Poisson's ratio shall be drawn with stress as the ordinate and Poisson's ratio as the abscissa. According to the curve, the Poisson's ratio o.4 when the stress α is equal to 0.4f. should be taken as the Poisson's ratio of the specimen.
Article 3.3.3
When the cross-sectional dimensions of the brick masonry do not meet the requirements of Article 3.1.1 of this standard, the compressive strength 0.4f. m value should be multiplied by the correction factor according to the test results. The correction factor Φ should be calculated according to the following formula:
Where——correction factor;
8—cross-sectional perimeter of the specimen (mm).
Article 3.3.4When the height-to-thickness ratio β of the medium-sized masonry specimen is greater than 3, the Engineering Construction Standard Full-text Information System
W1. Calculate the average width and average thickness of the specimen measured. Article 3.3.2 The elastic modulus E value and the measured value of Poisson's ratio of a single specimen shall be calculated according to the following steps:
1. The axial strain e and transverse strain &tr under step-by-step loads shall be calculated according to the following formulas:
(3.3.2-1)
etr = r
Engineering Construction Standard Full-text Information System
(3.3.2-2)
Engineering Construction Standard Full-text Information System
e——Axial strain value under step-by-step load
eu—Transverse strain value under step-by-step load; 1, lr——Axial and transverse deformation values under step-by-step load (mm);
lltr—The distance between axial and transverse measuring points (mm). 2. The stress under the step-by-step load shall be calculated as follows: N
Where g is the stress value under the step-by-step load (N/mm2); N is the step-by-step load value borne by the specimen (N). (3.3.2-3)
3. The relationship curve between stress and axial strain shall be drawn with g as the ordinate and 8 as the abscissa. According to the curve, the secant modulus when the stress α is equal to 0.4f. m shall be taken as the elastic modulus of the specimen and shall be calculated as follows: E
Where E is the elastic modulus of the specimen (N/mm2); 8a4 is the axial strain value corresponding to 0.4f. 4. The Poisson's ratio corresponding to the step-by-step stress shall be calculated as follows: V=et
(3.3.2-4)
(3.3.2-5)
The relationship curve between stress and Poisson's ratio shall be drawn with stress as the ordinate and Poisson's ratio as the abscissa. According to the curve, the Poisson's ratio o.4 when the stress α is equal to 0.4f. should be taken as the Poisson's ratio of the specimen.
Article 3.3.3
When the cross-sectional dimensions of the brick masonry do not meet the requirements of Article 3.1.1 of this standard, the compressive strength 0.4f. m value should be multiplied by the correction factor according to the test results. The correction factor Φ should be calculated according to the following formula:
Where——correction factor;
8—cross-sectional perimeter of the specimen (mm).
Article 3.3.4When the height-to-thickness ratio β of the medium-sized masonry specimen is greater than 3, the Engineering Construction Standard Full-text Information System
W
Tip: This standard content only shows part of the intercepted content of the complete standard. If you need the complete standard, please go to the top to download the complete standard document for free.