【作者】 刘至飞；

【导师】 文进； 吴少鹏；

【作者基本信息】 武汉理工大学 ， 建筑材料与工程， 2010， 硕士

【摘要】 温拌沥青混合料是一种节能环保型的新型沥青混合料,其拌和和压实温度与传统的热拌沥青混合料相比低10-60℃,同时又具有与热拌沥青混合料相当的路用性能。温拌沥青混合料是沥青行业又一项很有前景的新兴材料。与热拌沥青混合料相比,温拌沥青混合料技术增加了建设成本,这成为制约温拌沥青混合料应用的一个重要因素。本文在总结现在已有的温拌沥青混合料技术原理基础上,总结发现4A沸石的结构特性使得其能作为温拌助剂。基于以上考虑本文合成了4A沸石并就4A沸石对沥青混合料的温度制度及路用性能的影响进行了研究。本文首先以粉煤灰为原料,用碱熔融-水热法制备了含结晶水的4A沸石。本研究采用正交试验详细分析了SiO2/Al2O3, Na2O/SiO2, H2O/Na2O、陈化时间、晶化时间等实验参数对合成沸石失水量的影响,从而优化得到了较佳的合成条件。结果表明：以粉煤灰合成含结晶水的4A沸石的最佳工艺参数为：n(Si02)/n(Al203)=1.9, n(Na2O)/n(SiO2)=2.0, n(H2O)/n(Na2O)=50,陈化温度为65℃,陈化时间为3h,晶化温度为90℃,晶化时间为4h。在制备4A沸石的基础上,评价了合成沸石对沥青混合料路用性能的影响。研究了不同合成沸石掺量对沥青混合料空隙率的影响,确定了合成沸石的最佳掺量及其降温的幅度。以马歇尔浸水稳定度及冻融劈裂强度比表征了混合料抗水损害能力；通过三点弯曲试验评价了混合料的低温抗开裂能力；通过间接拉伸疲劳试验方法对比了各种沥青混合料在抗疲劳性能方面存在的差异；并采用车辙试验评价了沥青混合料的高温抗车辙变形能力。结果表明：掺加0.3%含结晶水的4A沸石,能降低拌和和压实温度20℃左右,并具有与热拌沥青混合料相当的路用性能,说明制备的4A沸石是一种温拌助剂。最后,对合成沸石温拌助剂的原理和节能环保效益进行了分析。结果表明：合成沸石的结晶水能改善沥青混合料在低温的的压实性能,因此合成沸石能降低混合料的拌和和压实温度。温拌沥青混合料降低了能源消耗及有害气体的排放,具有显著的社会效益。更多还原

【Abstract】 Warm mix asphalt (WMA) is a new kind of asphalt mixtures with energy saving and environmental protection. Warm mix asphalt is mixed and compacted at temperatures in the range of 10 to 60℃lower than typical hot mix asphalt, without compromising the performance of the asphalt pavements. Warm mix asphalt technology has the potential for being one of the most important breakthroughs for the asphalt industry. Compared with hot mix asphalt, the construction costs of warm mix asphalt are more expensive because of the warm mix asphalt technologies, which has became a key problem restricting the progress of warm mix asphalt concrete. Based on the existing principle of the warm mix asphalt technologies in this paper, it was found that the structural characteristics of zeolite 4A make it to a potential warm mix asphalt additives. Hence, the zeolite 4A was synthesized and the effect of zeolite 4A on the temperature parameters and performance of asphalt mixture were analyzed.Zeolite 4A containing crystal water was synthesized from coal fly ash by fusion with sodium hydroxide prior to hydrothermal reaction. The influence of some factors was investigated by orthogonal then the synthesis conditions were optimized. The results indicate that the best technological conditions of synthesizing zeolite 4A containing crystal water with coal fly ash are the mole ratio of SiO2/Al2O3 is 1.9; the mole ratio of Na2O/SiO2 is 2.0; the mole ratio of H2O/Na2O is 50; under the aging temperature of 65℃, the optimum aging time is 3h; under the crystallization temperature of 90℃, the optimum crystallization time is 4h.Based on the synthesis of 4A zeolite, the effect of zeolite 4A on the performance of asphalt mixture was analyzed. The influences of zeolite 4A volume of voids were researched and the dosage and decreased temperatures were identified. Water damage resistance property was evaluated adopting Marshall Water Submerged Stability test and Freeze-Thaw Split test; adopting bending test the lower-temperature cracking resistance of asphalt mixture was evaluated; indirect tension fatigue tests were also carried out and adopting rutting test the higher-temperature deformation resistance of asphalt mixture was evaluated. The results indicate that the mixing and compaction temperatures of warm mix asphalt with 0.3%zeolite 4A containing crystal water was 20℃lower than the traditional hot mix asphalt without sacrificing the quality of the pavement performance, indicating synthetic zeolite is a warm mix asphalt additives.At last, a comprehensive analysis of the principle of the zeolite 4A as warm mix asphalt additives and the energy-saving environmental benefits were performed and the results show that the compaction properties of asphalt mixtures at low temperature can be improved by the crystal water of zeolite 4A, which can be used to produce warm mix asphalt. With energy saving and environmental protection, warm mix asphalt has significant social benefits.更多还原