硫酸钙晶须和秸秆纤维改性沥青及其路用性能研究
发布时间：2019-05-13 22:12
【摘要】：伴随着交通量及车辆荷载的增加,沥青路面的病害问题日益凸显,在荷载和环境的综合作用下路面容易出现各种形式的损坏(如车辙、拥包、松散、推移、开裂等)。从沥青混合料入手,改善其路用性能也成为当下的研究热点。本文提出了硫酸钙晶须和秸秆纤维复合改性沥青。将硫酸钙晶须(calcium sulfate whisker,CSW)和秸秆纤维作为复合改性剂加入基质沥青中,研究复合改性后沥青的技术性质及沥青混合料的路用性能。首先采用XRD、SEM及实验室常规分析手段,对CSW的物相、形貌等基本技术性质进行测试,并对秸秆纤维的吸油性、吸水性、热稳定性等进行测试,结果表明所选CSW及秸秆纤维均满足沥青改性剂的基本要求。用机械搅拌法制备CSW改性沥青,测试改性沥青技术指标,结果表明:在CSW掺量0-8wt%范围内,70#沥青和90#沥青针入度、延度均有所下降,软化点均升高,70#沥青针入度指数PI从-1.3793增加至-0.7834,│VTS│从1.4311一直降低到0.4139,90#沥青PI从-1.4773增加至-0.8397,│VTS│从2.1341一直降低到0.4434,CSW可以改善沥青的粘滞性、温度稳定性、温度敏感性,降低了塑性。用机械搅拌法制备CSW和秸秆纤维复合改性沥青,测试改性沥青技术指标,结果表明:在CSW0-6wt%,秸秆纤维0-0.5wt%范围内,随改性剂掺量的增加,沥青锥入度降低、抗剪强度增加,10℃、15℃延度最大降幅分别为61%、40.5%,软化点从49.1℃增加到62.3℃,温度敏感性系数从0.0337一直降到0.0279,│VTS│从2.1339一直降到0.3536,复合改性可以改善沥青的粘滞性、温度稳定性、温度敏感性。通过RTFOT和PAV实验发现复合改性剂对沥青耐老化性有一定的改善作用。选取SAC-16沥青混合料,用VCADRF法对拟用矿料进行级配检验,通过马歇尔法对沥青混合料进行配合比设计。进一步分析硫酸钙晶须和秸秆纤维复合改性沥青混合料的性能,通过车辙实验,发现复合改性沥青混合料动稳定度DS最高增幅为34%,抗车辙性有较为显著的提升;通过间接拉伸实验,发现在一定掺量范围(CSW0-4%,秸秆纤维0-0.5%),复合改性沥青混合料劈裂强度、劲度模量最大增幅分别为29%、40%,低温抗裂性有所改善;通过冻融劈裂实验,发现冻融劈裂强度比TSR由83.2%增加到93.2%,水稳定性亦得到改善;用灰关联分析法,综合评价了复合改性剂掺量对混合料路用性能的影响程度,选取了最优掺配比例为CSW掺量4wt%,秸秆纤维掺量0.5wt%。
[Abstract]:With the increase of traffic volume and vehicle load, the disease problem of asphalt pavement is becoming more and more prominent. Under the combined action of load and environment, pavement is prone to various forms of damage (such as rut, wrapping, loose, moving, cracking, etc.). Starting with asphalt mixture, improving its road performance has become a hot research topic at present. In this paper, the composite modified asphalt of calcium sulfate whisker and straw fiber was proposed. Calcium sulfate whisker (calcium sulfate whisker,CSW and straw fiber were added as composite modifiers to the matrix asphalt. The technical properties of the modified asphalt and the road performance of the asphalt mixture were studied. Firstly, the phase and morphology of CSW were tested by XRD,SEM and conventional laboratory analysis, and the oil absorption, water absorption and thermal stability of straw fiber were tested. The results show that the selected CSW and straw fiber meet the basic requirements of asphalt modifier. CSW modified asphalt was prepared by mechanical mixing method, and the technical index of modified asphalt was tested. the results showed that the penetration and ductility of 70 # asphalt and 90 # asphalt decreased and the softening point increased in the range of 0 脳 8wt% of CSW. 70 # asphalt penetration index PI increased from-1.3793 to-0.7834, 鈮，
本文编号：2476222
[Abstract]:With the increase of traffic volume and vehicle load, the disease problem of asphalt pavement is becoming more and more prominent. Under the combined action of load and environment, pavement is prone to various forms of damage (such as rut, wrapping, loose, moving, cracking, etc.). Starting with asphalt mixture, improving its road performance has become a hot research topic at present. In this paper, the composite modified asphalt of calcium sulfate whisker and straw fiber was proposed. Calcium sulfate whisker (calcium sulfate whisker,CSW and straw fiber were added as composite modifiers to the matrix asphalt. The technical properties of the modified asphalt and the road performance of the asphalt mixture were studied. Firstly, the phase and morphology of CSW were tested by XRD,SEM and conventional laboratory analysis, and the oil absorption, water absorption and thermal stability of straw fiber were tested. The results show that the selected CSW and straw fiber meet the basic requirements of asphalt modifier. CSW modified asphalt was prepared by mechanical mixing method, and the technical index of modified asphalt was tested. the results showed that the penetration and ductility of 70 # asphalt and 90 # asphalt decreased and the softening point increased in the range of 0 脳 8wt% of CSW. 70 # asphalt penetration index PI increased from-1.3793 to-0.7834, 鈮，
本文编号：2476222
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