The Mechanical Properties Of PVA-steel Hybrid Fiber Reinforced Polymer Emulsion Cementitious Plate

Fiber reinforced polymer cementitious composite is a new type of cement-based composite materials which combines fine-grained concrete with high performance fiber and polymer emulsion.It can significantly improve the brittleness of ordinary cementitious material,and its strength,toughness,tensile resistance,bending resistance and crack resistance are obviously superior to ordinary cementitious materials.At present,fiber reinforced polymer cementitious composite have not been popularized and used in practical engineering.One of the most important factors is the production cost of the fiber.Although the performance of fiber reinforced polymer cementitious composite is excellent,it is expensive and can not be widely used.Therefore,two kinds of PVA fibers are used in this paper--large diameter PVA fiber made in Japan(B-PVA)and small diameter PVA fiber made in China(S-PVA).B-PVA fiber can significantly improve the mechanical properties of cement-based composite plate,but because of its expensive price,it can not be widely used.While the improvement of S-PVA fiber is not significant,but because of its low prices,it is expected to be used in the architectural structure of the future.In this paper,the compression test、 tensile test and three point bending test were carried out with the volume content of S-PVA and B-PVA and the content of polymer styrene butadiene emulsion as variables.The S-PVA fibers,after the surface oil treatment,mixed with steel fibers and styrene butadiene emulsion was tried to narrow the gap between the mechanical properties of S-PVA fiber specimens and B-PVA fiber specimens,discussing the effect of PVA type,PVA volume content and the content of styrene butadiene emulsion on the strength,ductility,toughness and fracture mode of cement-based composite plate containing steel fiber.It is found that the addition of styrene butadiene emulsion will greatly reduce the compressive strength of the test block.The addition of PVA fiber also reduces the compressive strength but not obviously,and the addition of steel fiber can enhance the compressive strength of the test block..The principle researches are as follows:(1)The main conclusions of cement-based composite plates’ three point bending tests are as follows: The improvement of the S-PVA fiber to cracking strength is limited.When the volume content of the fiber is more than 1.2%,the cracking strength of cement-based composite plates is not increased with the increase of the volume content of the fiber,and there is also no obvious effect on the ultimatestrength.With the increase of volume content of S-PVA fiber,the ductility,crack number and toughness of cement-based composite plates first increased and then decreased.B-PVA fiber has a certain effect on the cracking strength and ultimate strength of cement-based composite plates.With the increase of volume content of B-PVA fiber,the ductility,crack number and toughness of cement-based composite plates also increase first and then decrease.The styrene butadiene emulsion not only improves the strength of the cement-based composite plates,but also has a great help to the ductility and toughness of the cement-based composite plates under the joint action of PVA fiber and steel fiber.(2)The main conclusions of cement-based composite plates’ uniaxial tensile tests are as follows:When the content of styrene butadiene emulsion is low and constant,the cracking stress,ultimate stress and ultimate strain of the cement-based composite plates are improved because of the addition of S-PVA fibers,but the ultimate stress increasing with the increase of S-PVA fiber volume content is limited.B-PVA fibers show a similar pattern to S-PVA fibers.The styrene butadiene emulsion increases the tensile strength of the cement-based composite plates,and also increases the ultimate strain of the cement-based composite plates because of the synergistic effect with the PVA fiber,which greatly improves the cracking mode of the cement-based composite plates.(3)The comparison between S-PVA fiber and B-PVA fiber cement-based composite plates shows that:with the help of proper styrene butadiene latex and steel fiber,after amino silicone oil treatment,the bending and tensile properties of S-PVA fiber specimens are not significantly different from those of B-PVA fiber specimens.A practical fiber reinforced polymer cementitious composite material which can give consideration to strength,ductility,toughness and cost is obtained.