FIELD: construction. SUBSTANCE: concrete mix is held out in the contractmeter at the given temperature in the period of 15-20 min., is heated with a taken speed up to the temperature by 5 C exceeding the given one and is held out at this temperature during 10- 15 min. Then the mix is cooled up to its initial temperature at which it is again held out during 5-10 min. After the completion of this endurance the cycle of heating and endurance of it at the obtained temperature with the subsequent cooling up to the initial temperature is repeated till the value of the concrete contraction before the next cooling is equal or exceeds the contraction value before the temperature rise. The time passed from the beginning of heating the last cycle is taken for the duration of the preliminary endurance of the concrete. EFFECT: enhanced accuracy and authenticity, ensured express feature and the simplified process of determination. 1 dwg
