【摘要】 为考察废弃混凝土砂浆组分的接触硬化性能,将与粗集料分离后的砂浆组分磨细,一组磨细粉体直接压制成型,另一组粉体通过加入磨细生石灰和石英砂调整Ca/Si摩尔比为1,在120℃,水固比为5∶1的条件下进行动态水热处理后压制成型.测定成型试块的表观密度、抗压强度、抗折强度、软化系数,以表征粉体的接触硬化性能.结果表明:磨细砂浆组分具有接触硬化性能,一定条件的水热反应可优化这种性能.XRD分析显示,水热反应产物主要为结晶不良的水化硅酸钙;成型试块的抗折强度、抗压强度最高分别为5.7 MPa和16.8 MPa,并具有一定的耐水性,软化系数达到0.7.粗集料种类及水热反应恒温时间对其接触硬化性能有一定影响.更多还原

【Abstract】 In order to investigate the contact-hardening mechanism of the mortar component of demolished concrete,the mortars were separated and ground.One group of the power was directly molded at a certain compression,and the other group was molded after hydro-thermal synthesis at the temperature of 120 ℃ with a water solid ration of 5 by adding ground lime and quartz sand to adjust Ca/Si morel ratio.The apparent density,compressive strength,flexural strength and softening coefficient of the molded specimens were measured immediately.The results have shown that the ground mortar has a contact-hardening property to some extent and after hydro-thermal reaction,this property is obviously improved.The reacting production is amorphous silicate calcium hydration by XRD analysis.The maximum flexible strength and compressive strength are up to 5.7 MPa and 16.8 MPa respectively,and the specimen has a certain water resistance property,of which the softening coefficient can be 0.7.The property of contact-hardening is affected by the styles of the coarse aggregates of the demolished concretes and the constant time of temperature.更多还原