Behaviours of reinforced concrete beams under low temperatures

Reinforced concrete (RC) structure applied in the Arctic engineering and low temperature environment keeps increasing. This paper, experimentally, analytically, and numerically investigated the ultimate strength behaviour of the RC beams under different low temperatures. This paper firstly reported the experimental studies on mechanical properties of the steel reinforcements and normal weight concrete under different low temperatures. Empirical formulae were developed to incorporate the influences of the low temperature on the mechanical properties of the steel reinforcements and concretes. The ultimate strength behaviour of the RC beams under low temperature were studied through twelve quasi-static tests. The influences of the low temperatures and flexural reinforcing ratio on the ultimate strength behaviours of RC beams have been analysed and discussed. Analytical models were developed to predict the resistances corresponding to first crack, steel yielding, and ultimate resistances of the RC beams under low temperatures. Finite element model (FEM) was also developed to simulate the ultimate strength behaviour of the RC beams under low temperature. The accuracies of the analytical models and FEM simulations were checked through validations of the predictions by different models against the test results.