For lack of laboratory and field performance data on stabilization of reclaimed asphalt pavement （RAP） aggregate and stabilized soil （S） for road bases and subbases construction, the influences of RAP/S ratio, cem...For lack of laboratory and field performance data on stabilization of reclaimed asphalt pavement （RAP） aggregate and stabilized soil （S） for road bases and subbases construction, the influences of RAP/S ratio, cement and fly ash content, modifying agent （MA） on the compact, unconfined compressive strength, indirect tensile strength and water stability of the CIR mixtures were investigated. The experimental results showed that the maximum dry density and the optimum moisture content of the mixture changed significantly with the RAP/S ratio and cement-fly ash content. Unconfined compressive strength, indirect tensile strength and water stability were improved significantly by the addition of MA, and the water stability was improved by nearly 20% on average. Scanning electron microscopy（SEM） images indicated that MA accelerated the hydration of cement-fly ash system. Needle-like AFt and fibrous C-S-H gel were observed in the mixtures, which resulted in the cementation effect among the CIR mixture particles and a more compact microstructure. All these could be the cause of high strength of the CIR mixtures with MA.展开更多
为了研究水泥与泡沫沥青对冷再生混合料性能的影响及作用机理,通过力学性能试验、路用性能试验分析了泡沫沥青用量和水泥掺量对冷再生混合料力学特性与路用性能的影响,基于数字图像处理技术、扫描电子显微镜(scanning electron microsco...为了研究水泥与泡沫沥青对冷再生混合料性能的影响及作用机理,通过力学性能试验、路用性能试验分析了泡沫沥青用量和水泥掺量对冷再生混合料力学特性与路用性能的影响,基于数字图像处理技术、扫描电子显微镜(scanning electron microscope,SEM)微观图像测试和工业计算机体层摄影(computed tomography,CT)无损检测技术,揭示了泡沫沥青的分散性状及水泥对泡沫沥青冷再生混合料的强度影响机理。结果表明:增大水泥掺量有助于提高泡沫沥青冷再生混合料的力学性能、高温稳定性与水稳定性,但过多的水泥不利于泡沫沥青冷再生混合料的低温性能,推荐水泥掺量控制为1%~1.8%较为适宜。泡沫沥青在冷再生混合料中呈独特的“点焊”分布,泡沫沥青分散面积与劈裂强度(ITS)之间有良好的二次函数关系。水泥对泡沫沥青冷再生混合料强度的影响机理在于,水泥水化产物形成的簇状嵌挤的加筋结构,提高了冷再生混合料的界面黏结强度,同时掺加水泥改善了泡沫沥青冷再生混合料的空隙级配,并维持冻融循环作用空隙级配的稳定。展开更多
基金Funded by the High-Tech Research and Development Program (863 National Program) of China(No.2009AA11Z106)
文摘For lack of laboratory and field performance data on stabilization of reclaimed asphalt pavement （RAP） aggregate and stabilized soil （S） for road bases and subbases construction, the influences of RAP/S ratio, cement and fly ash content, modifying agent （MA） on the compact, unconfined compressive strength, indirect tensile strength and water stability of the CIR mixtures were investigated. The experimental results showed that the maximum dry density and the optimum moisture content of the mixture changed significantly with the RAP/S ratio and cement-fly ash content. Unconfined compressive strength, indirect tensile strength and water stability were improved significantly by the addition of MA, and the water stability was improved by nearly 20% on average. Scanning electron microscopy（SEM） images indicated that MA accelerated the hydration of cement-fly ash system. Needle-like AFt and fibrous C-S-H gel were observed in the mixtures, which resulted in the cementation effect among the CIR mixture particles and a more compact microstructure. All these could be the cause of high strength of the CIR mixtures with MA.
文摘为了研究水泥与泡沫沥青对冷再生混合料性能的影响及作用机理,通过力学性能试验、路用性能试验分析了泡沫沥青用量和水泥掺量对冷再生混合料力学特性与路用性能的影响,基于数字图像处理技术、扫描电子显微镜(scanning electron microscope,SEM)微观图像测试和工业计算机体层摄影(computed tomography,CT)无损检测技术,揭示了泡沫沥青的分散性状及水泥对泡沫沥青冷再生混合料的强度影响机理。结果表明:增大水泥掺量有助于提高泡沫沥青冷再生混合料的力学性能、高温稳定性与水稳定性,但过多的水泥不利于泡沫沥青冷再生混合料的低温性能,推荐水泥掺量控制为1%~1.8%较为适宜。泡沫沥青在冷再生混合料中呈独特的“点焊”分布,泡沫沥青分散面积与劈裂强度(ITS)之间有良好的二次函数关系。水泥对泡沫沥青冷再生混合料强度的影响机理在于,水泥水化产物形成的簇状嵌挤的加筋结构,提高了冷再生混合料的界面黏结强度,同时掺加水泥改善了泡沫沥青冷再生混合料的空隙级配,并维持冻融循环作用空隙级配的稳定。
