Concrete strength evaluation method

Abstract

The invention provides a concrete strength evaluation method which comprises the following steps: fitting the relationship between the strength and the age of a concrete test cube under the standard curing condition; carrying temperature match curing on the concrete test cube by simulating the temperature procedure of construction site concrete, and actually measuring the actual strengths of the concrete at multiple test ages; calculating equivalent ages according to the test ages by combining assumed activation energy parameter values in the pilot calculation process, and substituting the equivalent ages into the fit relationship between the strength and the age to obtain calculated strength values; using a least square method to calculating the error between the actual strengths and thecalculated strengths, and carrying out regression analysis to obtain the activation energy parameter value which enables the error to be the minimum; and calculating the strength value of the construction site concrete based on the fit relationship according to the activation energy parameter value and temperature monitoring data of the construction site concrete. Strength evaluation in the method takes individual characteristics and operating environments of materials into account, thereby improving the universality.

Description

technical field [0001] The invention belongs to the field of concrete quality monitoring and relates to a method for evaluating concrete strength. Background technique [0002] At present, the on-site evaluation of the strength performance of concrete materials mainly adopts the same condition curing method. Due to the limited size of the test piece and the influence of human operation, the compressive strength of the concrete formed at the construction site is quite different from the actual strength of the concrete member. Especially for mass concrete, the maximum internal temperature of mass concrete can reach 60°C or even higher, and the high temperature lasts for a long time. Therefore, in the early stage of mass concrete hardening, the concrete is essentially a high-temperature hardening process, which is equivalent to a "quasi-steam curing" state. As far as the relationship between cement hydration rate and temperature is concerned, the higher the temperature, the f...

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Problems solved by technology

[0012] Generally speaking, the equivalent age method has improved the evaluation accuracy compared with the Sauer formula, but the operation is more complicated, and concrete and mortar test blocks need to be formed, and the setting time of the mortar at each curing temperature needs to be measured separately. Setting too frequently, for example, when curing at 60°C, the setting time of the mortar test block is much earlier than that at normal temperature, so its use is greatly restricted and its operability is not strong

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