不同粒径橡胶集料混凝土工程特性试验

用橡胶颗粒取代砂子,对橡胶集料混凝土进行工作性测定及单轴抗压试验、抗水渗试验、抗氯离子渗透试验、冻融循环试验。结果表明:存在最不利橡胶颗粒粒径0.63～1.25 mm,使混凝土流动性最差;混凝土抗压强度随橡胶颗粒粒径减小而下降,但掺入小粒径橡胶颗粒有助于保证混凝土完整性;存在最优取代粒径0.165～0.315 mm,使混凝土电通量、渗水高度、质量损失率、相对动弹性模量损失率分别为普通混凝土的53.15%、52.35%、16.35%、51.79%;利用耐久性最优配合比制备的橡胶集料钢筋混凝土简支梁起裂荷载高于普通钢筋混凝土简支梁,但极限荷载有所降低,降幅约为6.10%。

Experiments of engineering characteristics for crumb rubber concrete with different rubber grain sizes

Rubber particles of different sizes were used to replace sand in the concrete which was exposed to workability test, uniaxial compression test, water permeability test, chloride penetration resistance test and freeze-thaw test. The results demonstrate that the fluidity of the crumb rubber concrete is minimized at the rubber particle sizes from 0. 63 to 1. 25 mm. The compressive strength of the concrete degrades as the rubber particle size decreases, while the introduction of small rubber particles has a positive effect on the concrete integrity. There exists an optimized particle size in the range from 0. 165 to 0. 315 mm, in which the electric flux, seepage height, mass loss rate and relative dynamic elastic modulus loss rate are 53. 15%, 52. 35%, 16. 35% and 51. 79% respectively of those for conventional concrete. Additionally, the prepared simply supported beam of crumb rubber concrete according to the ratio for optimized durability has a crack initiation load higher than that of a simply supported beam made of conventional reinforced concrete, but its ultimate load is 6. 10% lower than that of the latter.