橡胶混凝土的基本力学特性的试验研究

Experimental Study on the Basic Mechanical Properties of Rubber Powder Concrete

用3种粒径(16目、20目、40目),4种掺量(50 L/m3、75 L/m3、100 L/m3、125 L/m3)的橡胶粉设计了12种配合比的橡胶混凝土,开展了橡胶混凝土(rubber powder concrete,RPC)的准静态力学试验,描述橡胶混凝土的受力破坏形态,研究橡胶粉的粒径、掺量对橡胶混凝土抗压强度、抗折强度及折压比的影响情况,确定橡胶粉的最佳粒径及掺量范围。试验结果表明:与普通混凝土相比,橡胶混凝土的破坏表现为延性破坏;随着橡胶粉掺量的增加,橡胶混凝土的7 d、28 d抗压强度和抗折强度逐渐降低;掺40目橡胶混凝土的7 d、28 d折压比总体优于基准混凝土,掺16目橡胶混凝土的7 d、28 d折压比先减小后增大,掺20目橡胶混凝土的7 d、28 d折压比的变化趋势差别较大;掺20、40目橡胶混凝土的韧性要好于掺16目橡胶混凝土;从折压比和韧性的评价指标来看,制备橡胶混凝土时,最佳粒径为40目,掺量应大于100 L/m3。

Rubber powders with a diameter of 40 mesh, 80 mesh, 120 mesh are used in mixing amounts of 15 L/m^3 ,30 L/m^3 ,60 L/m^3 ,90 L/m^3 ,110 L/m^3 to make 12 kinds of rubber powder concrete（ RPC ）. The quasi static mechanical experiment of rubber powder concrete has been carried out to describe the damage forms of the loaded rubber powder concrete, study the effect the rubber powder＇s diameter and mixing amount have on rubber powder concrete＇s pressure-resisting properties, bend-resisting properties and ratio of bending-compressive strength and figure out the best range of rubber powder＇s diameter and mixing amount. The testing results show： compared with ordinary concrete, the failure of rubber powder concrete is ductile ; with the increase of the mixing amount of rubber powder, the rubber powder concrete 7 d and 28 d pressure-resisting strength decreases gradually; with the increase of rubber powder＇s mixing amount, the 7 d and 28 d ratio of bending-compression strength of rubber powder concrete with a diameter of 40 mesh is better than that of ordinary concrete, rubber powder＇s 7 d and 28 d ratio of bending-compression strength decrease at first and increase later on and the change tendency of 7 d and 28 d ration of bending-compression strength of rubber powder concrete with rubber powder of 20 mesh diameter are greatly different ; the toughness of the rubber powder concrete with rubber powder of 20 or 40 mesh diameter is better that that with rubber powder of 16 mesh diameter; judging from the toughness and ratio of bending-compression strength, it is better to use rubber powder of 40 mesh diameter make the mixing amount greater than 100 L/m^3 to make rubber powder concrete.