Study On Mix Proportion Design Of Ultra-high Performance Concrete Based On CPM Model And Specific Strength

The paper proposes a new design method of UHPC ,according to the specific strength method proposed by Professor Pu-Xin-cheng and CPM medol; The influence of the different proportion of mineral micro-power on pozzolanic effect and the packing density is also analyzed; The thesis mainly carries on research of the packing density to simulate pozzolanic effect and composite pozzolanic effect; and carries on the fitting between these quantities and packing density through the mathematical instrument; obtains the corresponding formula, confirms its relativity; Finally, the paper proposes the design method and the procedure of concrete, and confirmes the design method through a designing example, simultaneously, discusses its serviceability. The major research accomplishments were summarized as follows:(1) When doped, under the same content, activity index and contribution value of packing density of various active mineral micro-power are close related, the bigger contribution value of packing density is, the higher activity index is, corresponding, the pozzolanic effect is bigger, and the numerical analysis had proven the rationality of the packing density of mineral micro-power simulating the pozzolanic effect.(2) When co-doped, in certain curing conditions and certain content of mineral micro-power, the variation law of contribution rate of pozzolanic effect with content and type of active mineral micro-power is similar with the variation law of contribution value of packing density with content and type of mineral micro-power. And changing tendency of the contribution value of packing density could approximately simulate the variation of the contribution rate of pozzolanic effect; The variation law of the contribution rate of composite pozzolanic effect with content and type of various active mineral micro-power is similar with the variation law of the contribution rate of composite packing density with content and type of active mineral micro-power, and changing tendency of the contribution rate of composite packing density may approximately simulate the variation of the contribution rate of the composite pozzolanic effect.(3) when co-doped, in certain curing conditions and certain content of mineral micro-power, the relevance between the contribution rate of pozzolanic effect and the contribution value of packing density of mineral micro-power is good, the confident fitting formula may be established; the contribution rate of pozzolanic effect could be calculated through the contribution value of packing density, and thus obtains the compressive strength under different proportion of UHPC.(4) The paper realizes the goal of guiding the design of UHPC using the CPM model and the specific strength method,and proposes the design principle and the design step; the design method is simple and direct, and it is easy to realize computerizing of mix design.