UHPC力学性能的多指标分级

Classification of material performance is a fundamental work for establishment of the structural design mythology. In order to explore reasonable performance classification for Ultra-high Performance Concrete (UHPC), three group tests were carried out with the steel fiber volume fraction as the main parameter, including the uniaxial tensile strength tests of UHPC with the equal compressive strength, the tensile performances tests of UHPC (initial cracking strength, tensile strength and peak tensile strain), and comparison tests of UHPC splitting tensile strength, bending tensile strength and uniaxial tensile strength. The experimental results show that there is no simple and linear relationship between UHPC tensile strength and compressive strength, UHPC should not be classified by single indicator of the compression strength, but should consider both compression and tension properties; with the increase of fiber fraction volume, the enhancement degree of the UHPC initial cracking strength, tensile strength and peak tensile strain are not the same, the tensile performances of UHPC should not be classified only by the tensile strength, but these three tensile properties indicators; there is no simple and linear relationship among the splitting tensile strength, bending tensile strength and the uniaxial tensile strength for UHPC, the tensile strength should be tested by the uniaxial tensile test. Based on the experimental study, the multi-indicators classification method considering fiber reinforcement is proposed. According to the statistical analysis results of a large number of literature data, the detailed classification and corresponding multi-indicators of UHPC mechanical properties are recommended.