Preparation And Flexural Properties Of The Layered Fiber Reinforced Cementitious Materials Composite Plate

The fiber reinforced cementitious material is a new kind of cement-based composite material,which has high tensile strength and good crack resistance.It overcomes the weakness of brittle failure of cement-based materials,which makes it widely used in civil engineering field.However,there are many different types of fibers with different properties.The effect of different fibers on the strengthening and improving effect of cement matrix is quite different.From the research of many scholars,we can find that the enhancement of the one type of fiber reinforced cementitious materials is single and limited.Compared with one type of fiber reinforced cementitious materials,the performance of hybrid fiber reinforced cementitious materials has remarkable improvement.But the ingredient and composition of the matrix is not the same in different fiber reinforced cementitious materials.Consequently,the fibers are not able to make full use of its enhancements if the several kinds of fibers mix together in hybrid fiber reinforced cementitious materials.By analyzing the advantages and disadvantages of different fiber reinforced cementitious material,this paper made steel fiber reinforced cementitious materials and PVA fiber reinforced cementitious materials composite the layered fiber reinforced cementitious materials composite plate by layer pouring to take full advantage of the two materials and realize advantageous complementarities.In this paper,the flexural properties of the layered fiber reinforced cementitious materials composite plate was studied.And the layered fiber reinforced cementitious materials composite plate compared with other type of hybrid fiber reinforced cementitious material in performance and cost.The study obtained the following results:(1)The effects of fiber length and cement strength on the tensile properties of PVA fiber reinforced cementitious materials were investigated.The results show that:The effect of the length of the PVA fiber and the strength of the cement is not independent,which together act to enhance the performance of PVA fiber reinforced cementitious material.The PVA fiber reinforced cementitious materials with the best strain hardening ability can be obtained when the PVA fiber and cement strength match each other.(2)Comparison the basic mechanical properties of PVA fiber reinforced reinforced cementitious materials and steel fiber reinforced cementitious materials,PVA fiber reinforced reinforced cementitious materials is a kind of high ductile fiber reinforced cementitious composites which has the behavior of achieve strain-hardening and multiple cracking.But its compressive strength and mortar fluidity is poor.The compressive,tensile and flexural strength of steel fiber reinforced cementitious materials is good.But its ductility is inferior to PVA fiber reinforced cementitious materials.And its number of cracks is small and the strain softens in the tensile test.(3)This paper proposed the idea and the production process of the layered fiber reinforced cementitious materials.And the effects of the thickness of the material layer and the position of the load location on the flexural properties of the layered fiber reinforced cementitious materials were investigated by four-point bending test.We found that the position of load location has an important effect on the bending resistance of the layered fiber reinforced cementitious material.When PVA fiber reinforced cement-based materials was under tension and steel fiber reinforced cement-based material was under pressure,the two materials can take full advantages and realize advantageous complementarities.Comparing the thickness of different material layers,it is found that the thicker the steel fiber reinforced cementitious material layer is,the higher the strength is,and the better the ductility with the thicker PVA fiber reinforced cement base material layer is.(4)By comparing the bending properties and the cost of the layered fiber reinforced cementitious material with the other fiber reinforced cementitious material,we found that the layered fiber reinforced cementitious material has obvious advantages in both mechanical properties and cost.