Experimental Study On Bending Behavior Of C40Concrete Beams At Early Age

Comparing with the entire expected useful life, the early age period of concrete is transitory, but most engineering accidents occur at this period, and the performance of concrete at the early age has a significant impact on the performance of late concrete. The mechanical properties of the study of concrete members at the early age have important theoretical significance and value of engineering applications.To this end, the paper studied the performance of flexural RC and SRC beams in the same maintain condition within28days based on compressive, tensile strength and elastic modulus of early C40concrete blended with early strength admixture. Based on the test of concrete at the early age, the article works as follows:(1) the bending tests for14C40concrete beams mixing with early strength agent which are loading in two points are conducted. Deflection and section strain at all levels of loads are obtained as well as crack development diagrams and load deflection curves under monotonic loads. On the basis of which, the impacts of loads and ages on bearing capacity and the impacts of prophase loaded on later bearing capacity are researched.(2) firstly, cross-section bearing capacity of steel reinforced concrete beam and reinforced concrete beam is deduced; then, comparsions between different theoretical calculation formulas as well as experimental results and analytic ones are conducted. Lastly, formulas for the bearing capacity of early age concrete beam are put forward.(3) concrete block tests:the uniaxial compression test on9blocks is conducted. On the basis of which, stress-strain curves of each age as the constitutive relations of finite element analysis which will be conducted later are obtained. Nonlinear finite element analysis of the beam specimens are carried out using the ABAQUS software, including carrying capacity and deformation. The analysis results are in compliance with the test results.