LONG-TERM DEFLECTION PREDICTION OF REINFORCED CONCRETE BEAMS

Three high-strength lightweight aggregate concrete beams were tested for long-term deflections. By comparison with the test results of 3 beams in this paper and 31 beams in other references, it is found that the design methods in corresponding standards and other existing models are not consistent with the test results. Based on equivalent bending moment method, section curvature induced by shrinkage and creep is analyzed. A simplified approach to evaluate creep and shrinkage effects in cracked concrete beams is presented, which considers creep and shrinkage deflections separately. With a clear physical concept and a simple formulation, the values obtained by the proposed method are found to be in good agreement with the test results and improvement is observed in comparison with the other existing methods.