The heat of hydration of cement causes the internal temperature rise at early age, particulary in massive concrete structures such as a mat-slab of nuclear reactor building or a dam or a large footing. As the result of the temperature rise and restraint of foundation, the thermal stress enough to induce concrete cracks can occur. Therefore, the prediction of the thermal stress is very important in the design and construction stages in order to control the cracks developed in massive concrete structures. And, more creep and shrinkage take place at elevated temperatures in young concrete. Thus the effect of creep and shrinkage must be considered for checking the stability and serviceability(crack, durability and leakage).
The objective of this study is largely two folded. Firstly, it is to develop a finite element program which is capable of simulating the temperature history in mass concrete. Secondly, it is the apply a finite element program to analyze the behavior of reinforced concrete structures considering creep and shrinkage at working loads and temperature rise.
It is shown that the analytical results of this study is in good agreement with experimental data available in the literature. But the temperature history in the outer parts of the structure do not fit well with experimental data due to the change ambient temperature, while the temperature history in the inner parts is in good agreement due to the adiabatic condition. In relation to the creep and shrinkage analysis, a 3-point bending beam is analyzied under the assumption of plane stress condition. Comparision with experimental data in the literature shows good agreement in the load-point deflection. The final deflection calculated by ACI model seems to be larger than that by BP model.
