Experimental Study On Mechanical Properties Of Hybrid Fiber Self-Compacting Recycled Concrete

Hybrid fiber self-compacted recycled concrete makes full use of the advantages of fiber concrete and self-compacted concrete.It not only protects the environment,improves the utilization rate of industrial waste and saves natural resources,but also effectively improves the shortcomings of ordinary concrete such as high brittleness and needs to be vibrated.Therefore,in this paper,recycled aggregates formed by crushing waste concrete are prepared with different types and diverse amounts of fibers at replacement ratios to study its effect on the basic mechanical properties of hybrid fiber self-compacting recycled concrete before and after high temperature.The main contents are as follows:(1)Taking the proportion of basalt fiber as a factor,the experimental study on basalt fiber self-compacted concrete is carried out.The results show that the reasonable amount of basalt fiber can effectively improve the mechanical properties of self-compacted concrete.(2)Taking the replacement rate of recycled aggregate and the proportion of basalt fiber as the factors,the experimental study on basalt fiber self-compacted recycled concrete is carried out.It is found that the mechanical properties of self-compacted concrete with different replacement ratio of recycled aggregate first increase and then decrease with the increase of basalt fiber content.(3)Considering the replacement rate of recycled aggregate,basalt fiber proportion and cellulose fiber content,the influence of these three factors on the mechanical properties of self-compacted concrete is analyzed by orthogonal test.It is found that the order of the influence of various factors on the mechanical properties of hybrid fiber self-compacted recycled concrete is: replacement rate of recycled aggregate > basalt fiber proportion >cellulose fiber content.(4)The mechanical properties of hybrid fiber self-compacted recycled concrete before and after high temperature are compared and analyzed,and the rule of its mechanical properties changing with temperature is obtained.The results show that: fiber self-compacted recycled concrete has stronger high temperature resistance than ordinary self-compacted recycled concrete;with the change of temperature,the residual strength rate of self-compacted recycled concrete with different hybrid fiber content is much higher than ordinary self-compacted recycled concrete.