Test Research On The Mechanical And Fracture Property Of HPC

On the basis of improving significantly the performance of concrete, HPC is made under strict quality control conditions, which apply modern concrete construction technology and choose high-quality raw materials. Though HRC has been studied and applicatde widely, systematic and comprehensive research for its mechanical property is insufficient; Few studies on HRC with variety of admixtures, even less studies on fracture property of HPC. Through a large number of experiments,this paper studies the basic mechanical property and fracture property of HPC adding different variety, in the case of single doped and blending of a variety of admixture (fly ash,silica powder and polypropylene fibers). The main contents include:(1)This paper has analyzed preparation theory of HPC, and determined the mix proportion of HPC by overall calculation method.The influencing rule of fly ash, silica powder and polypropylene fibers on the performance of HPC was obtained though the test of slump and slump spread.(2)With 3d,7d,28d,90d as the age, the law of effects of the fly ash, silica powder and polypropylene fibers on the strength of HPC is obtained, though the test of cubic compression strength and splitting tensile strength.(3)With 28d as the age, the law of effects of the fly ash, silica powder and polypropylene fibers on the axial compressive strength and elastic modulus of HPC is obtained, though more convenient and accurate method of elastic modulus. Simultaneously, the formula of elastic modulus is obtained, taking the volume weight and cubic compression strength of concrete as variables, according to the regression analysis of test data.(4)With 28d as the age of concrete specimens, the flexural strength and flexural modulus are studied, and the law of effects of the fly ash, silica powder and polypropylene fibers on flexural strength and flexural modulus of HRC is obtained by three-point loading experiment. (5)With 28d as the age of concrete specimens, the fracture performance of HPC is studied by three-point bending beam test, with a set of specimens which size is 100mm×100mmm×515mm and pre-crack depth is 40mm. The influnce law of the fly ash, silica powder and polypropylene fibers on the fracture property of HPC is obtained though effective crack length, fracture toughness, critical crack opening displacement and limit crack opening displacement as evaluation indexes.