Investigation of Rubber Aggregate and Polymer Modified Concrete Pavement Wearing Layer Material
|School||Wuhan University of Technology|
|Keywords||Rubber aggregates Polymer emulsion Pavement wearing layer materials Strength Stress-strain properties Abrasion resistance Impact performance|
The increasing quantity of scrap rubber results in environmental pollution, and public security. Two kinds of polymer modified rubber aggregate concrete pavement wearing layer materials were developed in this paper, their fabrication and curing styles were optimized preliminarily, their mix proportions were optimizing designed, their mechanical properties, stress-strain relationship, abrasion resistance, and impact performance of this material were studied.It is found that the suitable preparing style beatifying to the strength development of rubber aggregate and polymer modified concrete is vibrated on vibrating table for 30 seconds, then keeping wet with plastic film for 7 days, and then keeping in nature condition. In addition, Styrofan D623 styrene-butadiene emulsion is a suitable polymer modifying agent for the concrete.The optimum mix proportion of rubber aggregate and polymer modified porous concrete is:1# aggregate:2# aggregate=9:1; polymer emulsion by 16%; replacement ratio of 1# rubber aggregate by 18%,2# rubber aggregate by 14%. The results indicate that:with the increases of rubber aggregate and polymer emulsion, the polymer modified rubber aggregate porous concrete gains higher flexural strength and compressive strength. The energy absorption capacity of polymer modified porous concrete is enhanced, and the toughness, abrasion resistance, impacting resistance of the polymer modified porous concrete are improved remarkably also.The optimum mix proportion of rubber aggregate and polymer modified compacting concrete is:1# aggregate:2# aggregate:3# aggregate=4:1:2, adding polymer emulsion by 20%; replacement ratio of 1# rubber aggregate by 20%,2# rubber aggregate by 15%. With the increases of rubber aggregate and polymer emulsion, the mechanical properties of the rubber aggregate and polymer modified compacting concrete are improved remarkably. Both limit stress and limit strain increase, the toughness, abrasion resistance, impacting resistance of polymer modified porous concrete are improved remarkably also. The SEM observation of rubber aggregate and polymer modified concrete indicate that:cement hydration degree can not be affected by the presence of polymer emulsion; continuous membrane structure is formed by dehydration polymer emulsion in concrete interior, which adheres to the surface of cement hydration products, concrete aggregate and rubber aggregate. In addition, in the special system of cement-rubber aggregate-polymer emulsion, the bonding strength between rubber aggregate and cement paste, rubber aggregate and concrete aggregate have been improved effectively, so the strength and toughness of the concrete have been improved remarkably.