Experimental Study On The Behavior Of High Strength Concrete Modified With Rubber Fine Aggregate Before And Under High Temperature

High strength concrete modified with rubber fine aggregate is a new type of green environmental building material. The high temperature performance of the high strength concrete could be enhanced by mixed into rubber (replacing fine aggregate sand with equal volume). For example, the defect of high temperature blasting will be improved by this way.At present, although a great deal of studies have been done for the high for the performance of ordinary concrete modified with rubber fine aggregate(rubber powder) under common temperature at home and abroad, few results are available for the high temperature performance of it. Therefore, from the perspective of building disaster reduction, study on the behavior of high strength concrete, which modified with rubber fine aggregate before and after high temperature, not only has a determined engineering application foreground, but also has theoretical value for the development of concrete technology.This paper references the fineness modulus as an evaluation index of rubber aggregate's fineness level, and a lot of researches have been carried out for the behavior of high strength concrete modified with rubber fine aggregate before and after high temperature, The researches include test of concrete mixture's consistency, test of concrete's apparent density and compressive strength and splitting tensile strength before and after high temperature, etc.The research results shows:? Mixing appropriate low-dosage rubber aggregate can improve the high temperature performance of high strength concrete. Electron microscope has been used to characterize the characterization analysis of hardened rubber cement paste, and to explain the change of concrete's mechanical properties from micro perspective.? Three factors and four levels orthogonal test was used to research the influence of rubber aggregate dosage, rubber aggregate thickness and calcination temperature of high strength concrete to the behavior of concrete. Results show that mixed 1.7% extra-fine rubber aggregate can restrain the high temperature blasting and improve the residual strength of it. But its degree of the influence is much less than the calcination temperature. The regression equations of concrete's strength and rubber aggregate content, fineness modulus and calcination temperature have been established, which has a certain instructive functions for engineering application.?Through single factor contrast experiment, the durability performance of C60 high strength concrete and C60 high strength concrete,which modified with 1.7% extra-fine rubber aggregate under different temperature(ordinary temperature,200?, 400?,600? and 800?), has been studied. The result shows that under normal temperature and more than 600? calcaination temperature the durability of C60 high strength concrete modified with 1.7% extra-fine rubber aggregate is much better than the others. In addition, the appropriate dosage of rubber aggregate can improve the durability of high strength concrete under normal temperature and more than 600? calcaination temperature.