The Effect of Curing Temperature on High-Strength Concrete Used in Precast Factories

The use of high-strength concrete in precast factories is a common solution to attain larger spans and columns with a higher load bearing capacity. Taking into account the cost for transforming the mold turnover in the precast line, it is economical to alter the concrete composition and the amount and size of reinforcement to attain the higher requirements. In collaboration with a precast factory, a test program was carried out to reveal the influence of concrete composition and curing temperature on material properties. The goal of the project was to predict the strength evolution of the material, using conventional maturity functions. Therefore, different concrete compositions were used, varying from concretes normally used on construction site, to high-strength concrete. Different curing temperatures were considered. The paper presents the evolution of the compressive strength in time, taking into account different parameters as well as the evaluation of existing maturity functions. Among others, the maturity functions of Plowman, of Kee, of Freiesleben-Hansen and Pedersen and of Carino are investigated. Especially the model, proposed by Carino predicted the strength evolution adequately.