Research Of The Effect On Steel Fiber And Rubber Powder On The Mechanical Characteristics And The Durability Of The Desert Sand Concrete

This thesis studies the mechanics property of two kinds of desert sand concrete by using the method of orthogonal experiment, in which desert sand, steel fiber and rubber powder and fly ash as a variable. It designs two sets of scheme, one mixed with steel fiber and fly ash, the other mixed with rubber powder and fly ash. And analyzes the compressive strength and splitting strength of concrete after the test and works out the optimal set. Then studies the frost resistance and wear-resisting strength of the optimal set of concret. It concludes that1.Through orthogonal experiment, it works out the optimal mix proportion of the steel fiber desert sand concrete and rubber powder desert sand concrete. The factors of Steel fiber is respectively that20%desert sand,15%dosage of fly ash,1.5%steel fiber.3%rubber powder in rubber powder group,20%desert sand,15%dosage of fly ash. This combination showed good workability and mechanical properties. It can provide reference for concrete with high durability of desert sand.2. Orthogonal experiment results show that the compressive strength and splitting strength of desert sand concrete mixed with steel fiber are significantly higher than the baseline group. The strength of the rubber powder is slightly below the baseline group, but it can satisfy the preparation of the concrete strength.3. The three groups of the grinding impact of the concrete experimental study shows that the wear-resisting strength of the reference concrete, steel fiber desert sand concrete and rubber powder desert sand concrete is17.07kg/m2/h,18.7kg/m2/h,22.61kg/m2/h, compared with the baseline group of concrete, the wear-resisting strength of two variety of concrete increased by9.56%and32.44%respectively, the wear-resisting strength of the desert sand concrete mixed with fiber and rubber powder are improved, the rubber powder group raise higher, steel fiber group improved lower.4.The three groups of concrete antifreeze test showed that at the beginning of the cold, the relative dynamic modulus of elasticityof the concrete of J, X group drop low, the improvement of the steel fiber to the frost resistance of concrete is not obvious. With the increase of freeze-thaw cycle, fiber enhancement effect began to emerge, to the end of the test looping150times, relative move of steel fiber modulus decreased slower than baseline group. Antifreeze performance of rubber powder group has steadily falling and is better than the other two kinds of concrete. Until the end of300experiments, relative loss modulus is Px> PG> PJ.5. From the index of the durability of freezing-thawing and resisting impact grinding can work out that:Respectively add fiber and rubber powder and mineral admixture to the desert sand concrete can improve the frost resistance and wear-resisting strength of the concrete. Improvement effect of steel fiber is poor, but the improvement effect of rubber powder on the properties of two kinds is obvious.