Generalized Equivalent Stress Block Model Considering Varying Concrete Compressive Strength and Unit Weight

摘要

In this study, a generalized equivalent Stress Block Model has been proposed that is applicable to all types of concrete, including lightweight and high-strength concrete (HSC). First, available stress-strain models for concrete were verified through an extensive database. Then, the coefficients used in the proposed stress blocks were formulated based on a nonlinear regression analysis of the values determined from the layer-by-layer integral evaluation approach. The hypothesis underlying this integral approach is that the magnitude and location of the resultant force in the equivalent stress distribution are the same as those in the actual distribution. The extreme compressive fiber strain ofO. 003 and the factor ofO. 85 used to compensate for the difference between the in-place strength and the cylinder strength were assumed, as was done for normalweight and/or normal-strength concrete (NSC). The reliability and safety of the proposed stress blocks were confirmed through comparisons with the flexural capacities measured from approximately 175 normalweight and 80 lightweight concrete (IMC) beams, and approximately 100 normalweight concrete (NWC) columns.