Study On The Properties Of Fiber Toughening Polymer Cement Concrete

The concrete near the bridge joints is crisp, unable to warp, easy to crack and non-durable. It's a tricky problem for the bridge builders. So it's necessary to do a further study on the impact of the polymer and the fiber on the mechanical properties, the permeability and shrinkage properties of the polymer cement concrete of the concrete, which is very important for improving the ductility and durability of the concrete.The results show that, the workability of the concrete is improved by the adding of polymer, the bleeding of concrete id reduced, the slump of the concrete is improved as the polymer is added. The polymer added in the concrete is not gathered in the pores of the concrete, most of it wraps outside of the cement particles, which reduces the volume density of the concrete and prolongs the setting time.As the polymer is mixed in, he elastic modulus of set cement is reduced by network skeleton formed by polymer, which reduces the compressive strength of concrete but improves the deformation ability and the compression toughness of the concrete. Polymer solidified on the surface of the aggregates improves the toughness of the connection between aggregates in the concrete, which result in the improving of the interface structure, the flexural strength, the shrinkage performance and the bend ductility of the concrete. Parts of the polymer solidify in pores of concrete, which reduces the quantity and the pore diameter and results in the reducing of the permeability of concrete.In this paper,the influences of the vinal and steel fiber on the toughness of the concrete are researched, it's found that SBR polymer latex improves the binding power between the vinal and the concrete, the vinal are snapped as the concrete cracking. The bend ductility of the concrete is little improved. While the steel fibers are added in, the bearing capacity and deformability are improved obviously. The steel fibers are pulled out while the concrete is cracking. So the toughness of the concrete is improved as the increase of the steel fibers.Besides, the influences of unit amount of cement, water-cement ratio and defoamer on the performance of the polymer cement concrete are also discussed in this paper and some valuable conclusions are gained.