Research On The Mechanical Properties Of Chopped Basalt Fiber Reinforced Rubber Concrete And The Structure Analysis Of Composite Pavement

Chopped Basalt Fiber Reinforced Rubber Concrete(shortfor CBFRC) is adding chopped basalt fiber to the rubber concrete, through the composite function with rubber particles, to effectively reduce the elastic modulus of concrete and reinforce the compressive strength and flexural strength, provides the possibility for shock absorption and noise reduction on the cement concrete pavement.The CBFRC cube compressive strength, axial compressive strength, static compressive elastic modulus, bending strength and other mechanical properties are studied in this paper. At the same time the structure of CBFRC-RCC composite pavement are put forward and the vehicle stress finite element are analyzed. The main research contents are as follows:(1) With the increasing content of rubber particles, concrete cube compressive strength and axial compressive strength decrease gradually. When the rubber particles content in 0 ~ 20%, the strength decreases slowly, then decreases quickly. When the rubber particle content reached 50%, the strength cannot meet the performance requirements of road pavement mechanics. At the same time, the incorporation of rubber particles also improves the failure pattern, and enhances its toughness obviously.(2) With the increasing content of rubber particles, the static compressive elastic modulus reduces gradually. When the rubber particles content in 0 ~ 30%, the strength decreases slowly, then decreases quickly. The formula between static compression elastic modulus and compressive strength are proposed, which is based on the experimental results. Rubber particles content is in 0 ~ 50%, concrete Poisson ratio increases from 0.1823 to 0.2125.(3) After 0.2% chopped basalt fiber mixed with rubber concrete, the compressive strength, axial compressive strength, elastic modulus and Poisson’s ratio are almost coincident with the raw rubber concrete, which show that the influence on the concrete is relatively small.(4) With the increasing content of rubber particles, the flexural strength decreases gradually, and with the increasing content of chopped basalt fiber, the flexural strength have obvious improvement.(5) The ratio k(known as the brittleness coefficient) of the cube compressive strength and flexural strength, which is called k(known as the brittleness coefficient), decreases with the increasing content of rubber particles and the content of chopped basalt fiber can further reduce the ratio.(6) Simulated by the finite element analysis software, the variation of CBFRC-RCC composite pavement structure under the vehicle stress: 1) the increasing of the elastic modulus decreases the adjacent plate bottom stress and increases the plate bottom stress; 2) when the composite pavement slab total thickness increases, the lower plate bottom stress decreases, but the upper stress increases with the decreasing of the upper and lower shelves relatively thickness; 3) the upper and lower slab bottom stress decreases with the increasing of the subgrade surface equivalent elastic modulus(Et).(7) According to the influence on the composite pavement stress, in the design of the CBFRC-RCC composite pavement, the following measures could be taken to reduce the plate bottom stress: 1) appropriately increasing the upper CBFRC’s elastic modulus and decreasing the lower RCC’s; 2) when the composite pavement slab total thickness is certain, can increasing the upper CBFRC’s thickness and decreasing the lower RCC’s; 3) appropriately increasing the subgrade surface equivalent elastic modulus(Et).