Long-term strength prediction of concrete with curing temperature

This paper describes a new strength time temperature prediction equation, which utilizes curing temperatures to improve the accuracy of estimates of long-term strength. To develop the model equation, existing data reported in the literature were collected and used. The data were converted into a relative strength ratio based on the strength at 28 days for 8 average curing temperatures in a range of -0.6 similar to 59.7 degrees C. The effect of the diffusion shell, which happens during cement hydration, on the long-term strength as a function of the curing temperature was considered using the rate constant model. Temperature influence factors such as rate constant, limiting strength, and reaction coefficient, which are functions of curing temperature, were incorporated in the new equation. Verification of the proposed model was performed by regression analysis. The results of regression analyses showed that the proposed model has higher reliability than existing model equations. The proposed model has higher accuracy at long-term ages the difference with existing models at an early age is not significant. (c) 2005 Elsevier Ltd. All rights reserved.