Research On Theory Of Concrete Framework Design

Based on centroplasm theory of Wu ZhongWei and continuous compact coordinate theory of Liu ChongXi, professor Wang LiJiu devises concrete framework model, that is coarse aggregate are accumulated most closely with some coordination form by mechanical mixing, vibrating and gravity and form the concrete structural frame, then the mortar is used to fill up the air gap, bond and strengthen the coarse aggregate and make a whole body with strength. In the theory of structural framework model, concrete is composed of coarse aggregate, mortal and interfacial transition zone, that is, concrete strength comes from coarse aggregate, mortar and interfacial transition zone.Research on concrete framework design theory based on the theory of concrete framework, devises frame-mortar ratio, that is the mass ratio of coarse aggregate and mortar, and physical meaning of which reflects the contribution ratio of framework and mortar to concrete integral strength, substitutes structural parameter frame-mortar ratio for technology parameter water-cement ratio, overcoms the limitation of conventional theory of concrete mix, and improves the concrete design.The essence of concrete framework theory is to deduce the cement dosage of unit volume concrete from frame-mortar ratio, unit water dosage and deviated function of cement-sand ratio.So, this thesis mainly includes four parts:Firstly: It is deduced that the relational theoretical formula between concrete strength and frame-mortar ratio based on framework concrete strength theory, and the specific mathematical model is obtained by test regression.Secondly: The conception of equivalent strength of hydraulic cement mortar is presented. The study establishes the deviated function of cement-sand ratio, focuses influence factors of the function on shape characteristic parameter sphericity of fine aggregate, geometrical average grain size and median diameter from analyzing the test result, and then asertains the cement-sand ratio of framework concrete.Thirdly: Researching the influence of shape and size of coarse and fine aggregate on concrete workability, the author quantified expresses the influence factor of aggregate upon water dosage with average sphericity of aggregates and geometrical average grain size of solid particles.Finally: According to the theory of concrete framework design, the research designs the framework concrete and compares the mechanical property of framework concrete to that of conventional concrete by testing.By testing, compression strength and elastic modulus of framework concrete satisfy designing requirement and it is also more economic because of less cement.The three basic parameters are established by considering the material character and creating math model and they make the framework design theory of concrete more systemetical, functional and scientific.