Experimental Study On Basic Mechanical Properties Of Waterborne Epoxy-based Polymer Concrete

As a porous,heterogeneous and porous inorganic brittle material,concrete is prone to micro-cracks under the influence of external loads and surrounding environment,which leads to local damage of the structure.This reduces the strength and stiffness of the concrete structure,shortens the service life of the concrete and affects the overall safety of the concrete structure.Sex.Therefore,it is of great significance to find a new cement-based material which can improve the working performance of concrete,improve the safety performance of building structures and prolong the service life of concrete.Epoxy resin has been widely used in civil engineering because of its high bonding,tensile,bending strength and cushioning properties.However,traditional epoxy resin is insoluble in water and can only dissolve in organic solvents such as aromatic hydrocarbons,ketones,alcohols and ethers.These solvents are highly volatile and have high relative cost.They are wasteful in resource utilization and natural environment.As a result,water-borne epoxy resin emerged as the times require,and gradually become the focus of research on clean materials.Waterborne epoxy resin is a kind of epoxy resin dispersed in physical or chemical form such as particles and colloids.It has a stable dispersion system.Unlike epoxy resin,waterborne epoxy resin can cure in a humid environment.When polymer is mixed with cement-based materials such as cement mortar and concrete,the mechanical properties of the concrete materials after mixing,such as early strength,toughness,impact resistance,waterproof and deformation ability,will be greatly enhanced.In this paper,the main research contents of waterborne epoxy-based polymer concrete are as follows:1.Adding different content of waterborne epoxy emulsion in ordinary concrete,preparing five different concrete specimens,and then testing the basic mechanical properties of concrete,such as compressive strength,tensile strength,bending strength and modulus of elasticity,and compared with the basic mechanical properties of ordinary concrete.It is concluded that when the amount of polymer is 10%,the basic mechanical properties of concrete can be improved very well.The test also shows that the incorporation of waterborne epoxy emulsion improves the flexibility coefficient of concrete material and promotes the transformation of concrete to flexible materials.2.From microcosmic mechanism,it is expounded that after adding waterborne epoxy emulsion to ordinary concrete,polymer can be interlinked with cement hydration products under the action of hydration heat of cement,so that the membrane structure can be synthesized.Polymer film will permeate and fill the gap between cement paste interface and aggregate particles,and change the structural form of cement paste in concrete structure.At the same time,scanning electron microscopy(SEM)was used to observe the micro-morphology of concrete specimens mixed with polymer,and the mechanism of the change was analyzed and discussed.3.The change of flexural bond strength between new and old concrete and the bond strength between polymer and concrete are studied after adding waterborne epoxy emulsion.By comparing with the pre-established ordinary concrete test group,it is found that the bonding performance of concrete mixed with polymer will be much lower than that of ordinary concrete.Observing the pull-out test phenomena of polymer concrete and steel bar,we find that the slip of steel bar in ordinary concrete is smaller in pull-out test,which indicates that the bond strength between steel bar and ordinary concrete is much higher than that between waterborne epoxy polymer concrete and steel bar.