Experimental Study On Bending Fatigue Performance Of Rubber-modified Recycled Aggregate Concrete For Airport Pavement

In connection with the concrete performance requirements for airport pavement, the mechanical properties、bending fatigue properties and damage mechanism of rubber-modified recycled aggregate concrete were analyzed to provide basis for the application of rubber-modified recycled aggregate concrete in airport pavement.By the standard cube compressive experiment, four-point flexural tensile experiment, it is obtained that the compressive strength of recycled aggregate concrete increased by10.1%compared with normal concrete. While, the compressive strength of rubber-modified recycled aggregate with rubber contents of10%,20%and30%decreased20.5%,33.1%and41.8%respectively. The flexural strength decreased by10.2%,16.4%,21.1%and28.6%for recycled aggregate concrete with rubber contents of0%,10%,20%and30%respectively. The compressive strength, flexural strength and bending elasticity modulus of rubber-modified recycled aggregate concrete decreased with the increase of the fractions of crumb rubber volumes. Combined with the airport pavement design specification, the rubber content not more than20%in rubber-modified recycled aggregate concrete mixture ratio design is suggested.By each group of concrete three point static bending test and collecting test data, it is obtained that the peak deflection, peak strain and ultimate strain of rubber-modified recycled aggregate concrete increased with the increase of the fractions of crumb rubber volumes. The ultimate strain can be increased by3.45times when the crumb rubber volume fraction is20%. Combined with the actual damage form, the rubber-modified recycled aggregate concrete toughness, crack resistance performance is more superior.Through three-point bending fatigue experiment, double logarithm fatigue equation for rubber-modified recycled aggregate is obtained and the ultimate fatigue strength of various of concrete prediction by using Weibull theory to analyze the results, When the rubber content reaches20%, the concrete fatigue life enhancement effect is the most significant. Rubber-modified recycled aggregate concrete in airport pavement can obviously prolong the service life of pavement, show some advantage.