Experiment Research On Rubber Expansion Concrete

The passage proposes to add expanding agent in rubber concrete, which formsrubber expansion concrete. It will doubly improve the behavior of concrete. Theaddition of expanding agent can compensate for the shrink of concrete and reduce itscracking inside in the early stage. The rubber concrete itself has preferable crackingresistance. After adding expanding agent, the cracking resistance of concrete increasesdramatically, forming high-cracking-resistance concrete. In addition to thecompensation of expanding agent for shrink, expanding agent will also densify thecement structure, which can increase the strength of concrete, making up for thedecrease of it due to the addition of rubber. Besides, the accretion of both rubber andexpanding agent can improve the durability of concrete like freeze-thaw cycleresistance and impermeability. As a result, the research on properties of rubberexpansion concrete, especially on durability offers a new idea for high performanceconcrete. And it makes great contributions to enlarge the application of rubberexpansion concrete as well as prolong the service life of concrete in practical project.Since it is the elementary research, the passage research on the free expansionperformance of rubber expansion concrete, basic mechanical properties, crackingresistance, freeze-thaw cycle resistance and impermeability. The content and result isas follows:（1） It researches the free expansion performance of rubber expansion concrete.Based on rubber concrete, it researches on the effect of expansion of concrete aftereach addition of0，5%,10%,15%volume fraction, with certain amount of expandingagent added in the rubber concrete. The result shows that the addition of rubberimproves the expanding effect of expanding agent and the expanding level goes upwith the increase of rubber.（2） According to the two different ways of addition methods, the first method isusing expanding agent instead of cement and the other one is adding expanding agentdirectly. It researches the basic mechanical properties of rubber expansion concrete. Inthe first method, it researches on the compressive, flexural, tensile splitting strengthunder the circumstances of different additions of rubber (0,5%,10%,15%), with theaccretion of expanding agent of0,4%,6%,8%,10%. The result shows that rubber playsthe dominant role in the effect of compressive, flexural, tensile splitting strength, andexpanding agent plays a secondary role. The strength of concrete decreases with the increase amount of rubber added and the strength varies with different amount ofexpanding agented inside. Under the influence of complex factors, the peak point ofeach proportion differs. In the second method,4groups of contrastive experiments areset to compare the compressive and flexural strength of ordinary concrete, rubberconcrete, expansion concrete and rubber expansion concrete in7days and28days.The result shows that the addition of expanding agent improves the compressive andflexural strength of rubber expansion concrete, simultaneously reduces thecompression flexure ratio.（3） In the research of durability, firstly mortar is chosen as research target tocompare the cracking resistance of ordinary mortar, mortar with expanding agent,mortar with rubber, mortar with both rubber and expanding agent. Then, it researcheson the impermeability and freeze-thaw cycle resistance of concrete with bothexpanding agent and rubber. And compare the two properties of concrete with bothexpanding agent and rubber with ordinary concrete, concrete with expanding agent,concrete with rubber. The result shows that concrete with both expanding agent andrubber has better cracking resistance, impermeability and freeze-thaw cycle resistancecompared to the other three kinds of concrete.