Experimental Study On The Influence Of Concrete Masonry Creep And Volumetric Stress

Temperature change and the drying shrinkage has Produced strain,and produced stress to deformation is constrained.When the tensile stress exceeds the tensile strength of the material structure,masonry will crack.Due to creep effect and stress relaxation,reducing the temperature and drying the shrinkage internal stress.Creep of masonry has big effect on the wall,but the masonry code in our country has not been included the relevant parameters,so its basic values with reference to foreign literature.Firstly,this paper study on ordinary concrete brick masonry in different stress creep.In the test,divided into two groups according to the vertical stress :0.15fm(QT1?QT2)and 0.3fm(QT3?QT4).Each group has two specimens.Laying a unloaded specimen(QT5)in the same condition test the strain of drying shrinkage and temperature.Through the results of research on masonry creep test,we get masonry creep with the stress increases.Contrary,creep coefficient decrease with the increase of stress.Secondly,This chapter proposed by Thomas F G index functional model,Dirichlet series model and hyperbolic-power function type model for fitting experimental data.In prediction model,we can get the final parameters,such as creep coefficient.Thirdly,assuming that the shrinkage are exponential functions,creep model of exponential function was obtained using the regression equation of experimental data,explicit equation for the dry shrinkage stress and the stress relaxation coefficients of the reinforced masonry members considering creep was derived by using the aging theory.The influence of the drying shrinkage stress of masonry with the reinforcement ratio and the restraint coefficient of reinforced masonry members was analyzed.Finally,Exponential functions explicit equation for the dry temperature stress and the stress relaxation coefficients of the masonry members considering creep was derived by using the aging theory.The influence of the temperature stress and the stress relaxation coefficients of masonry was analyzed.