Experimental Study On The Mechanical Properties Of Rubber Mortar

As a new type of building material,rubber concrete(mortar)has been tested and theoretically studied by domestic and foreign scholars on its mechanical properties,working performance and durability since its appearance.The results show that rubber concrete(mortar)has the characteristics of low strength and high toughness compared with base concrete(mortar).But,there are still some imperfections in the above research results.The axial and three point bending tests of rubber mortar prism are carried out in this paper.The effects of rubber content,rubber particle size and strength of mortar matrix on the peak load,the displacement of load point corresponding to the peak load and the load displacement curve under the peak load are studied in this paper.The main contents are as follows:(1)According to the ?Code for design of masonry mortar mix ratio?the mix ratio of base mortar and rubber mortar specimens is given in the form of tabular form.Rubber is added to the premixed mortar by means of equal volume replacement of sand.The calculation process of the mixing method of rubber particles is given,which lays the foundation for the development of the follow-up test and the analysis of the test results.(2)The axial compression test of rubber mortar prism was carried out.The influence of rubber particle size on the mechanical properties of rubber mortar specimens was studied,and the reasons were analyzed.The effect of the change of rubber particle size on the energy dissipation capacity of rubber mortar specimens and the damage form of axial pressure is studied through the analysis of the load displacement curve shape and the area of the lower package.The failure process of each specimen is compared and analyzed.(3)Based on the axial compression test of rubber mortar prisms,the stress-strain curves of each group of specimens were analyzed.The effect of the change of rubber particle size on the peak stress,peak strain and modulus of elasticity was studied.The peak stress and peak strain of each specimen were compared and analyzed.According to the stress-strain curve of the specimen,a suitable mathematical expression of constitutive relation model is selected,and the variation of formula parameters with the particle size of rubber is studied by regression analysis.(4)The test of three point bending of rubber mortar was carried out.The influence of rubber particle size on the peak load,the mid span displacement and the load area of the load displacement curve of the specimen is studied.The influence of rubber particle size on the load displacement curve morphology of rubber mortar specimens is also analyzed.Finally,the whole process of damage and fracture of typical specimens is analyzed based on the image of crack growth recorded in the loading process.(5)The effects of rubber content and mortar matrix strength on the flexural properties of rubber mortar were studied.By comparing the peak load,the mid span displacement and the load displacement curve under the peak load and the load displacement curve,the influence of the rubber content and the strength of the mortar matrix on the above results is systematically analyzed.The schematic diagram of peak load,mid span displacement and the area of the curve under the change of rubber content and matrix strength are given.