CN-121994669-A - Test method for measuring chloride ion permeability resistance of cement paste by using electric flux method

Abstract

The invention provides a test method for measuring the chlorine ion permeability resistance of cement paste by an electric flux method, which comprises five steps of manufacturing a cement paste test piece, preprocessing the cement paste test piece, clamping the cement paste test piece, measuring the current and the actual electric flux passing through the cement paste test piece, and calculating the electric flux conversion value of the cement paste test piece. According to the invention, through reasonably controlling the direct-current constant voltage value, the risk of damaging an instrument due to larger current passing through the cement paste test piece in a test is reduced, meanwhile, the adverse effect on a test result caused by rapid rise of solution temperature and electrode reaction under the action of long-time higher direct-current constant voltage is reduced, and the semi-quantitative evaluation of electric flux among cement paste test pieces with different mixing ratios under the same age is finally realized.

Inventors

• DENG CHAO
• HU WEI
• YU JUNYANG
• DOU LIGANG
• LU YONGJIU
• LIU LIMIN
• REN YUEJUAN

Assignees

• 长江三峡技术经济发展有限公司
• 中国长江三峡集团有限公司

Dates

Publication Date

20260508

Application Date

20260115

Claims (10)

1. 1. The test method for measuring the chloride ion permeability resistance of the cement paste by using the electric flux method is characterized by comprising the following steps of: S1, manufacturing a cement paste test piece; s2, pretreating a cement paste test piece; S3, clamping a cement paste test piece; s4, measuring the current and the actual electric flux passing through the cement paste test piece; and S5, calculating an electric flux conversion value of the cement paste test piece.
2. 2. The test method for measuring the chloride ion permeability resistance of the cement paste by using the electric flux method according to claim 1, wherein the test piece of the cement paste is clamped on a concrete durability comprehensive tester in the step S3.
3. 3. The method for measuring the chloride ion permeability of the cement paste according to claim 1, wherein in the measuring process in the step S4, a UV direct current constant voltage is applied to two ends of a cement paste test piece, the current of the cement paste test piece subjected to vacuum water saturation pretreatment within t hours is measured, the actual electric flux of the cement paste test piece passing through the time t hours of electrification under the UV direct current constant voltage is obtained, and finally the electric flux conversion value of the cement paste test piece passing through the time t hours of electrification under the UV direct current constant voltage is obtained through a conversion formula.
4. 4. The test method for measuring the chloride ion permeability resistance of the cement paste by using the electric flux method according to claim 3, wherein the voltage value of the UV direct current constant voltage is 0-60V, and the electrifying time t is 6h.
5. 5. A test method for measuring the chloride ion permeability resistance of cement paste by an electric flux method according to claim 3, wherein the voltage value of the UV direct current constant voltage is 6V, 10V, 15V, 20V, 30V.
6. 6. The test method for measuring chloride ion permeability resistance of cement paste by using electric flux method according to claim 4 or 5, wherein the actual electric flux of the cement paste test piece is electrified for 6 hours under UV direct current constant voltage And the concrete durability comprehensive tester is used for testing to obtain the concrete durability comprehensive tester.
7. 7. The test method for measuring the chloride ion permeability resistance of the cement paste by using the electric flux method according to claim 6, wherein the electric flux conversion formula in the step S5 is as follows: ; in the formula, To represent the electric flux conversion value of the cement paste test piece after the C U is converted into the 60V direct current constant voltage and electrified for 6 hours, The actual electric flux of the UV direct current constant voltage passing through the cement paste test piece for 6 hours is shown, For a current at the time of 6 hours, To be used in Conversion to The calculated power-on time is a multiple of the power-on time of the cement paste test piece, t is the power-on time of the cement paste test piece, and 3.6 is a unit conversion value of coulomb C=A.s and mA.h.
8. 8. The test method for measuring the chloride ion permeability of the cement paste by using the electric flux method according to claim 7, wherein the conversion formula is characterized in that the direct current constant voltage values at two ends of a cement paste test piece are changed, and the power-on time of a certain multiple is correspondingly prolonged when the electric flux conversion value is calculated.
9. 9. The method for measuring the permeability of cement paste against chloride ions by using an electric flux method according to claim 7, wherein when the direct current constant voltage UV at two ends of a cement paste test piece is 6V, 10V, 15V, 20V and 30V, the power-on time in the conversion formula is a multiple of the extension And a 6 =X、A 10 =0.4992X、A 15 =0.2946X、A 20 =0.2134x and a 30 =0.1323X, wherein X is a multiple of the power-on time to be prolonged in a conversion formula when the direct current constant voltage UV at two ends of the cement paste test piece is 6V.
10. 10. The method for measuring the permeability of cement paste against chloride ions by using an electric flux method according to claim 7, wherein when the direct current constant voltage UV at two ends of a cement paste test piece is 6V, 10V, 15V, 20V and 30V, the power-on time in the conversion formula is a multiple of the extension A 6 =10.000、A 10 =4.992、A 15 =2.946、A 20 =2.134 and a 30 =1.323.

Description

Test method for measuring chloride ion permeability resistance of cement paste by using electric flux method Technical Field The invention relates to the field of building materials, in particular to a test method for measuring the permeability of cement paste against chloride ions by an electric flux method. Background Concrete durability refers to the ability of concrete to resist the action of environmental media and maintain its good service performance and appearance integrity for long periods of time, thereby maintaining the safe, normal use of the concrete structure. Since the 60 s of the 20 th century, the problem of durability of concrete has been increasingly appreciated by expert students. In the life cycle of service, the concrete structural member used in actual engineering is subjected to influences of freeze thawing, carbonization and acid-base corrosion, so that the use function and the structural safety can be damaged, and especially, the aggregate used in eastern area has commonly existing alkali activity, the potential alkali-aggregate reaction is more serious, and more serious challenges are presented to the durability of the concrete. It has been found through many years of research that various failure mechanisms affecting the durability of concrete are related to the permeability of concrete, and measuring the chloride ion permeation resistance of concrete is one of the important methods for evaluating the durability of concrete. The electric flux method is the most popular concrete permeability quick evaluation method internationally at present, and the quality of the concrete anti-chloride ion corrosion performance is evaluated according to the electric flux of a test piece within 6 hours under the constant voltage of 60V. Although the electric flux method is simple and quick, the defects are more, the accuracy of test results is poor, and especially for cement paste with inferior impermeability than concrete, under 60V direct current constant voltage, on one hand, the instrument is easily damaged due to high current generated by the poor impermeability of the cement paste, and on the other hand, the temperature of the solution and the temperature of the test piece are rapidly increased due to the fact that the current is large, the working time is long, electrode reactions are generated, and therefore the cement paste test piece is deteriorated to cause the distortion of the test results. Disclosure of Invention The invention aims to provide a test method for measuring the chlorine ion permeability resistance of cement paste by an electric flux method, which reduces the risk of damaging an instrument due to larger current passing through a cement paste test piece in a test by reasonably controlling a direct current constant voltage value, simultaneously reduces the adverse effect on test results caused by rapid rise of solution temperature and electrode reaction under the action of long-time higher direct current constant voltage, and finally realizes semi-quantitative evaluation of electric flux among cement paste test pieces with different mixing ratios in the same age. In order to realize the technical characteristics, the invention aims at realizing the test method for measuring the chloride ion permeability resistance of the cement paste by using an electric flux method, which comprises the following steps: S1, manufacturing a cement paste test piece; s2, pretreating a cement paste test piece; S3, clamping a cement paste test piece; s4, measuring the current and the actual electric flux passing through the cement paste test piece; and S5, calculating an electric flux conversion value of the cement paste test piece. Preferably, in the step S3, the cement paste test piece is clamped on a concrete durability comprehensive tester. Preferably, in the measuring process in S4, a UV direct current constant voltage is applied to two ends of the cement paste test piece, the current of the cement paste test piece subjected to vacuum water saturation pretreatment within t hours is measured, the actual electric flux passing through the cement paste test piece after being electrified for t hours under the UV direct current constant voltage is obtained, and finally the electric flux conversion value of the cement paste test piece after being electrified for t hours under the UV direct current constant voltage is obtained through a conversion formula. Preferably, the voltage value of the UV direct current constant voltage is 0V-60V, and the electrifying time t is 6h. Preferably, the voltage value of the UV direct current constant voltage is 6V, 10V, 15V, 20V and 30V. Preferably, the cement paste test piece is electrified for 6 hours of actual electric flux under UV direct current constant voltageAnd the concrete durability comprehensive tester is used for testing to obtain the concrete durability comprehensive tester. Preferably, the electric flux conversion formula in S5 is: ; in the formula