聚酯纤维增强型水泥稳定砂砾基层抗裂性试验研究

发布时间：2018-03-08 23:04

本文选题：聚酯纤维　切入点：水泥稳定砂砾　出处：《新疆大学》2014年硕士论文　论文类型：学位论文

【摘要】：半刚性基层一直是我国高速公路及城市道路建设中最常用的基层类型，，其中水泥稳定类基层又因其强度高、板体性好等特点而被广泛使用。作为西部最常用半刚性基层，由于水泥稳定砂砾固有干缩湿涨、低温收缩以及抗弯曲变形能力差等性质，不可避免的会产生开裂变形。微裂缝一旦在基层中产生，在环境和荷载因素作用下，会向上扩展而使沥青路面产生反射裂缝，反射裂缝也是我国西部地区危害路面安全的最主要病害之一。首先，本文探究了半刚性沥青路面的裂缝形成机理，并总结了路面裂缝常用预防措施。针对新疆地区常用的水泥稳定砂砾半刚性基层，提出通过掺加聚酯纤维来提高其抗裂性。按照规范要求，对混合料的骨架密实型级配进行合成级配设计，并按照丙法对水泥稳定砂砾进行电动击实试验，得出最大干密度和最佳含水量。试件在保证压实度的前提下采用静压成型，在标准条件下养护规定龄期。然后通过无侧限抗压强度、抗弯拉强度和弯拉回弹模量试验及收缩试验，探究聚酯纤维对水泥稳定砂砾的强度和抗变形能力的影响规律。最后，分析了现有半刚性基层抗裂性的评价指标和方法，总结了各评价方法的差异性。通过对纤维水泥稳定砂砾进行多指标评价，找出纤维长度和掺量的最佳组合。试验证明，聚酯纤维在水泥稳定砂砾中充分发挥了增强、增韧和阻裂作用，聚酯纤维水泥稳定砂砾抗裂效果较好。
[Abstract]:Semi-rigid base is the most commonly used base course in expressway and urban road construction in our country, and cement stabilized base is widely used because of its high strength and good plank etc. It is used as the most commonly used semi-rigid base in the west of China. Due to the inherent dry shrinkage and moisture rise of cement stabilized gravel, low temperature shrinkage and poor ability to resist bending deformation, cracking and deformation will inevitably occur. Once microcracks occur in the base, under the action of environment and load factors, The asphalt pavement will expand upward to produce reflective cracks, which are also one of the most important diseases that endanger the road safety in the western part of China. First of all, this paper probes into the crack formation mechanism of semi-rigid asphalt pavement, and summarizes the common preventive measures of pavement crack, aiming at the cement stabilized gravel semi-rigid base course commonly used in Xinjiang area. It is proposed to improve the crack resistance by adding polyester fiber. According to the specification, the composite gradation design of the framework dense gradation of the mixture is carried out, and the electric compaction test of cement stabilized gravel is carried out according to the C method. The maximum dry density and optimum moisture content are obtained. The specimen is formed under static pressure on the premise of ensuring compaction, and the age of the specimen is maintained under standard conditions. Then, through the unconfined compressive strength, The effects of polyester fiber on the strength and deformation resistance of cement stabilized sand gravel were investigated by means of flexural tensile strength and flexural elastic modulus test and shrinkage test. Finally, the evaluation indexes and methods of crack resistance of semi-rigid base are analyzed, and the differences of each evaluation method are summarized. The optimum combination of fiber length and content is found. The test results show that the polyester fiber can strengthen, toughen and prevent the crack in cement stabilized gravel, and the effect of polyester fiber cement stabilizing sand gravel is better.
【学位授予单位】：新疆大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U416.21

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