天然砾石骨料界面与沥青胶浆粘附性能研究

发布时间：2018-08-22 07:31

【摘要】：沥青混凝土因具有极佳的防渗性能被广泛应用于沥青混凝土心墙坝中。在工程实践中水工沥青混凝土得到了迅速发展,但在材料研究方面还显得不够完善。进行沥青混凝土配合比设计时,为保证骨料与沥青的粘附性及心墙的防渗安全可靠性,沥青混凝土骨料一般都选用了碱性岩石破碎的碎石。但人工破碎岩石成本高,且带来一定的环境问题,而在新疆地区,天然砾石骨料分布范围广、可就地取材、方便经济。由于天然砾石骨料岩性复杂,酸碱性不宜判断,用天然砾石骨料配制的沥青混凝土粘附性能能否达到碱性破碎骨料的要求,仍需进一步的研究和试验论证。本文主要从天然砾石骨料界面和沥青胶浆两方面考虑,分别分析了天然砾石骨料酸碱性的判定方法,研究了不同沥青胶浆的物理力学性能,在此基础上进一步研究了砾石骨料界面与沥青胶浆的粘附强度,以骨料界面与沥青胶浆的拉伸强度这一力学性能作为评价二者粘附性优劣的直接指标,结论如下:(1)在工程实践中,应该首先采用岩相法对砾石骨料的酸碱性进行初步判定,再采用SiO2含量法和碱值法进行综合判定。碱度模数法不建议采用。(2)填料浓度在很大程度上影响沥青胶浆的性能,相同试验条件下,填料浓度越大,沥青胶浆的针入度越小,软化点越高,拉伸强度越大;填料级配也会影响沥青胶浆的性质,填料级配越细,沥青胶浆的针入度越小,软化点越高,拉伸强度越大。(3)保证填料级配相同,在相同的骨料界面上,水泥沥青胶浆比石灰石粉沥青胶浆有更强的粘附性,且在48h浸水作用以后,水泥沥青胶浆与花岗岩骨料界面的拉伸强度仍然大于石灰石粉沥青胶浆与花岗岩骨料界面的拉伸强度,水泥沥青胶浆有更强的抵抗水损害作用的能力。花岗岩骨料界面与沥青胶浆的拉伸强度也随填料浓度的增加而增大。(4)试验研究和工程实践均已证明以水泥为填料不仅可以有效提高沥青与骨料的粘附性,还可以很好的改善沥青混凝土的施工和易性,提高心墙沥青混凝土的变形能力。
[Abstract]:Asphalt concrete is widely used in asphalt concrete core dam because of its excellent impermeability. Hydraulic asphalt concrete has been developed rapidly in engineering practice, but it is not perfect in material research. In order to ensure the adhesion between aggregate and asphalt and the safety and reliability of core wall, asphalt concrete aggregate is generally selected alkaline rock crushed stone in the design of asphalt concrete mix ratio. However, the cost of artificial rock crushing is high, and it brings some environmental problems. In Xinjiang, natural gravel aggregate is widely distributed and can be obtained locally, which is convenient for economy. Because of the complex lithology of natural gravel aggregate, it is not suitable to judge acid and alkalinity. Whether the adhesion property of asphalt concrete prepared with natural gravel aggregate can meet the requirement of alkaline crushed aggregate still needs further study and test. In this paper, considering the interface of natural gravel aggregate and asphalt mortar, the methods of judging the acidity and basicity of natural gravel aggregate are analyzed, and the physical and mechanical properties of different asphalt mortar are studied. On the basis of this, the adhesion strength between gravel aggregate interface and asphalt mortar is further studied. The mechanical properties of aggregate interface and asphalt mortar are taken as the direct indexes to evaluate the adhesion between them. The conclusions are as follows: (1) in engineering practice, we should first use lithofacies method to determine the acidity and basicity of gravel aggregates, and then use SiO2 content method and alkali value method to comprehensively judge the acidity and basicity of gravel aggregates. The alkalinity modulus method is not recommended. (2) the concentration of filler greatly affects the performance of asphalt mortar. Under the same experimental conditions, the greater the filler concentration, the smaller the penetration of asphalt mortar, the higher the softening point and the greater the tensile strength; Filler gradation will also affect the properties of asphalt mortar. The finer the filler gradation, the smaller the penetration of asphalt mortar, the higher the softening point, and the greater the tensile strength. (3) ensuring the same filler gradation, at the same aggregate interface, The cement asphalt paste has stronger adhesion than limestone powder asphalt mortar, and after 48 hours of soaking, The tensile strength of the interface between cement asphalt mortar and granite aggregate is still higher than that between limestone powder asphalt mortar and granite aggregate, and cement asphalt mortar has stronger ability to resist water damage. The tensile strength of the interface of granite aggregate and asphalt mortar also increases with the increase of filler concentration. (4) it has been proved by experiment and engineering practice that cement as filler can not only improve the adhesion of asphalt to aggregate effectively. It can also improve the construction and easiness of asphalt concrete and improve the deformation ability of core wall asphalt concrete.
【学位授予单位】：新疆农业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U414

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