Method for rapidly predicting 28-day colloidal mortar compression strength of cement

A technology of compressive strength and prediction method, applied in the fields of water conservancy engineering, civil engineering, and construction industry, can solve the problems of different strength development laws, large prediction deviation, low correlation coefficient, etc., and achieve high homotropic correlation coefficient and high accuracy. , the effect of small workload

Active Publication Date: 2010-12-29
SHENZHEN UNIV
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Problems solved by technology

[0025] In addition, there are also the following problems in the "Quick Test Method for Cement Strength" JC / T738-2004: 1. The hydration process and strength development law of different cement varieties and different grades are different. Using the same prediction formula, there are prediction deviations Larger cases; 2. The correlation coefficient of the regression strength prediction formula is required to be low, above 0.75 is enough, and there are cases where the correlation is low

Method used

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  • Method for rapidly predicting 28-day colloidal mortar compression strength of cement
  • Method for rapidly predicting 28-day colloidal mortar compression strength of cement
  • Method for rapidly predicting 28-day colloidal mortar compression strength of cement

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0082] Check "General Portland Cement" GB 175-2007, it can be seen that the percentage of Portland cement in the total mass of cement is ≥80% and <95%, and then according to the reference material of cement C value (when it is greater than 65%, the C value is 1.3, When 50%-64%, the C value is 1.4, when 35%-49%, the C value is 1.5, and when 35%-49%, the C value is 1.5), and the C value of the cement is determined to be 1.3.

[0083] When placed in the humid heat curing box, the temperature is 24°C, and the results of calculating the weight maturity and strength are as follows:

[0084] Age 4h:

[0085] Age 5.5h:: 1.5h is from 24°C to 55°C, this part is calculated according to the average temperature

[0086]

[0087] Age 9h: Demoulding 0.5h ahead of time and taking out the test piece, this part is calculated based on the laboratory temperature of 20°C, and the constant temperature time of 55°C is 9h-0.5h-5.5h=3h

[0088] M 9 ...

Embodiment 2

[0108] Check "General Portland Cement" GB 175-2007, it can be seen that the percentage of Portland cement in the total mass of cement is ≥80% and <95%, and then according to the reference material of cement C value (when it is greater than 65%, the C value is 1.3, When 50%-64%, the C value is 1.4, when 35%-49%, the C value is 1.5, and when 35%-49%, the C value is 1.5), and the C value of the cement is determined to be 1.3.

[0109] The temperature in the humid heat curing box is 22°C, and the results of calculating the weight maturity and strength are as follows:

[0110] Table 5. Test results of weight maturity and compressive strength of a certain brand P.O32.5R

[0111] Age (h)

Maturity M(℃.h)

lm w

Compressive strength (MPa)

9

481.2

2.68

8.2

24

1874.9

3.27

17.4

27.5

2173.2

3.34

18.2

32

2566.9

3.41

19.9

48

4055.8

3.61

24.6

[0112] C...

Embodiment 3

[0118] Check "General Portland Cement" GB 175-2007, it can be seen that the percentage of Portland cement in the total mass of cement is ≥80% and <95%, and then according to the reference material of cement C value (when it is greater than 65%, the C value is 1.3, When 50%-64%, the C value is 1.4, when 35%-49%, the C value is 1.5, and when 35%-49%, the C value is 1.5), and the C value of the cement is determined to be 1.3.

[0119] The temperature in the humid heat curing box is 25°C, and the results of calculating the weight maturity and strength are as follows:

[0120] Table 7. Test results of weight maturity and compressive strength of a certain brand of P.O42.5R

[0121] Age (h)

Maturity M(℃.h)

lm w

Compressive strength (MPa)

9

485.7

2.69

14.5

24

1879.4

3.27

22.6

27.5

2177.8

3.34

30.5

32

2571.4

3.41

34.5

48

4060.3

3.61

37.3

[012...

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Abstract

The invention relates to a method for rapidly predicting 28-day colloidal mortar compression strength of cement. In the method, an idea of Netherlands weighted maturity (also known as C value maturity) is adopted; a C value of a foreign cement weighting coefficient is referred to; the temperature measuring process is simplified; a group of colloidal mortar test blocks are formed by utilizing the conventional JC/T 738-2004 cement rapid test equipment; the compression strength in different ages is tested in 48 hours under the condition of hydrothermal curing at the temperature of 55 DEG C; a relation of the weighted maturity and the strength is established; and the 28-day strength of the cement is predicted according to the relation. Research shows that the method for rapidly predicting the 28-day colloidal mortar compression strength of the cement is feasible and effective and has high prediction accuracy on the 28-day strength.

Description

technical field [0001] The invention belongs to the fields of construction industry, civil engineering and water conservancy engineering, and relates to the detection technology of the compressive strength of cement mortar. Background technique [0002] The 28-day mortar compressive strength of cement is the most important quality index of general-purpose Portland cement, and is the basis for determining the cement strength grade and concrete quality grade. According to the requirements of CB / T17671-1999, the compressive strength test cycle is long and requires 28 days, seriously affected the cement concrete production, construction quality control and progress. In order to improve the construction speed, save the construction period, ensure the quality of concrete, and make full use of the activity of cement, many engineers and technicians have conducted a lot of research on the method of quickly testing the compressive strength of cement. [0003] According to the data, t...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G01N3/08G01N1/44
Inventor 邢锋罗启灵韩宁旭
Owner SHENZHEN UNIV
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