SU1695229A1 - Method for checking the process of hardening of concrete articles at heat treatment - Google Patents

Description

(21) 4755332/33 (22) 11/02/89 (46) 11/30/91. Bul

(71) Kursk Polytechnic Institute

(72) V.V. Bredikhin, S.I. Merkulov and V.G. Starodubtsev

(53) 620.1 (088.8)

(56) USSR author's certificate

Ns 343221, cl. G01 N33 / 38, 1970.

USSR author's certificate Ns 643803, cl. G 01 N 33/38. 1975. (54) METHOD OF CONTROL OVER THE EXTENSION OF STRENGTH OF CONCRETE PRODUCTS UNDER HEAT TREATMENT

(57) The invention relates to the production of concrete and reinforced concrete products in precast concrete plants. The purpose of the invention is to improve the accuracy of control. The temperature of the concrete is measured in the upper and middle sections along the height of the product. The time from the moment of mixing of the concrete mixture to the time of measuring the temperature of the concrete is determined. A differential exponent of the degree of maturity of concrete is determined, and an increase in the strength of concrete products is judged by the relative strength of concrete,

This invention relates to the manufacture of concrete and reinforced concrete products in precast concrete plants.

The purpose of the invention is to improve the accuracy of control.

The method is carried out as follows.

During the entire heat treatment process of a concrete product, the temperature of the concrete is measured in the upper and middle sections along the height of the product. The temperature difference between the upper and middle sections of the product is determined and the time from the moment of mixing of the concrete mixture to the time of measuring the temperature of the concrete is determined. Calculate the differential rate (AH) degree of maturity of concrete by the formula

AH-CAT,

where K is constant for a particular type of cement, taking into account its dispersion;

AT is the temperature difference between the upper and middle sections of the product;

At is the time from the moment of mixing the concrete mixture to the moment of measuring the temperature of the concrete;

t is the time taken to measure the temperature of the concrete.

Then calculate the relative strength of concrete ROTH (t).

ROTU):

J

No

fax) z2

Z

J

Jz

Sya

where X is an indicator of the degree of maturity of concrete;

Z - concrete strength at 28 day old;

And X is a differential indicator of the degree of maturity of concrete;

t is the heat treatment time; 6. - The basis of natural logarithms.

The integrals summarize if the differential maturity degree of concrete has a positive value, and subtract if the differential maturity degree index of concrete has a negative value.

Yu Yu

Claims (1)

The invention The method of monitoring the increase in strength of concrete products during heat treatment, including measuring the temperature of the bud at certain points in time, determining the time until the temperature of the concrete is measured, determining the maturity of the concrete, calculating the relative strength of the concrete judged by increasing the strength of concrete products, which is due to the fact that, in order to increase the accuracy of control, the temperature of concrete is measured in the upper and middle sections along the height of the product, the time from This concrete mixture until the temperature of the concrete is measured, the differential maturity value of the concrete is determined, the relative strength of the bfton is calculated by the formula fax)  . lk ; v Jz) where X is an indicator of the degree of maturity of concrete; Z - concrete strength at 28 days of age; AH is a differential indicator of the 10 degree of maturity of concrete; t is the heat treatment time; c is the base of the natural logarithms, while the integrals summarize if the differential index of the degree of ripeness of concrete has a positive value, and subtract if the differential indicator of the maturity of concrete has a negative value. fax)  . lk ; v Jz)