Research on the Short-Time Deflection of Concrete Beams Reinforced with 500MPa Steel Bars
Fourteen concrete beams reinforced with 500MPa longitudinal steel bars were tested under two-point symmetrical concentrated static loading to investigate their deflection characteristics. And the formula for short-time stiffness specified in the code for design of concrete (GB50010-2010)were evaluated using the experimental results and available test data of 74concrete beams reinforced with 500MPa longitudinal steel bars. The results show that the deflection behavior of beams with 500MPa longitudinal steel bars is essentially similar to that of beams reinforced with conventional steel reinforcements. It is also shown that the formula for short-time stiffness under service loads specified in GB50010-2010 is applicable for flexural members reinforced with 500MPa longitudinal steel bars. Comparisons of the test results with the calculated values for the short-time deflection according to GB50010-2010 show that the code method can be used to estimate the short-time deflection for beams reinforced with 500MPa longitudinal steel bars, but that the method is somewhat less accurate for beams with light reinforcement ratio and low-strength concrete.