Research On Cross-section Crack Width Varying With Section Depth Of Reinforced Concrete Beams

Based on the bending test data of the cross-section crack width of 10 reinforced concrete beams, the paper studied that the cross-section crack width varies along with the section depth of beams and how to calculate it. The main results as follows:(1) The height of cross-section cracks heightens with the load increases. When the load up to a certain value, height of cross-section cracks slowly heightens, and even stops. Through the experimental results analyzed, the formula about M/M_u and h_cr/h₀ is(2) The experiment results indicate that The flexural deformation is the very important factor that influences the crack width in normal section of reinforced concrete flexural beams.(3) Based on test result of 10 reinforced concrete beams, the relationship of the average crack width of lateral surface and bottom surface is(4) It is a suggestion that a certain amount of constructional reinforcement is allocated to control the crack and reinforcement mat is collocated in the concrete cover to inhibit the crack development for large concrete cover of reinforced concrete members.(5) According to the theoretical model and analysis of the test results, calculation of the cross-section crack width of reinforced concrete bending members can be done by the formula:where:The formulas above agree well with the test results.