废轮胎橡胶粒在水泥浆体内之接口问题

探讨粉碎后之废轮胎橡胶颗粒表面改质方法,以强化其与水泥浆间作用力的问题.使用之改质剂有氢氧化钠溶液、含硫量较高之润滑油与甲苯.粉碎之橡胶颗粒依其粒径大小分为三群.试体除做抗压、抗拉与抗剪等强度测试以了解物理及机械性质外,并以金相显微镜实时观测水化过程中橡胶与水泥结合情况.实验结果发现,以氢氧化钠处理过之橡胶颗粒与水泥泥之结合最好,此乃因强化其表面亲水性,有利于与水泥作用.反之以甲苯处理之橡胶结果最差,因其表面之亲水性较小.以润滑油处理之橡胶所得试体之性质较不稳定,此与含硫量与处理过程有关.文中并提出以显微镜做线上实时观测试体表面水化变化以做为试体制作改进之参考依据.此方法可降低试体制作之庞大人力与材料费用.

Rubber Tire Particles in Cement Paste

The surface of powdered tire rubber was modified to enhance its adhesion to cement paste in this study. Sodium hydroxide solution, waste lubrication oil, and toluene etc. were used as adsorbed agents to modify the surface of the powder. Rubber particles were divided into three groups according to their particle sizes. Specimens with various amounts of rubber and different particle sizes were prepared to evaluate their physical properties. Microscopy was used to observe the structure of the specimens. Flexural, compressive and tensile strengths of the specimens were also measured in the experiments. Experimental results show that the saturated solution of sodium hydroxide is the most efficient agent among the three modification agents in enhancing the adhesion of rubber particle to cement paste. It is suggested that the adsorption of sodium hydroxide on the rubber surface will enhance the hydrophilic characteristics of surface. Lubrication oils with sulfur compounds, which carry free electron pairs, are expected to be useful in modifying the rubber surface to increase the interaction force between rubbers and cements. However, compositions and amounts of sulfur compounds within the lubrication oils were out of control in our experiments therefore no consistent results were gotten. As a surface modification agent in our experiments, toluene was less useful. The adsorption of toluene on the rubber surface will enhance its hydrophobic characteristics and will reduce the interaction force between rubbers and cements. It is believed that the interaction force between rubbers and cements dominates the mechanical properties of these specimens and the modification of rubber surface should be a main topic to be studied.