天然砾石骨料在沥青混凝土心墙中的适用性研究

发布时间：2018-03-02 22:24

本文选题：天然砾石骨料　切入点：沥青混凝土心墙　出处：《新疆农业大学》2014年硕士论文　论文类型：学位论文

【摘要】：为研究和探讨天然砾石骨料在沥青混凝土心墙中的适用性，结合新疆五一水库工程，通过黏附性试验，研究了不同岩性天然砾石骨料与纯沥青之间的黏附性能；在沥青中分别加入水泥、消石灰粉、白云岩粉、凝灰岩粉制成不同的沥青胶浆，进行不同岩性天然砾石骨料与不同沥青胶浆的黏附性试验，探讨了增强骨料与沥青黏结力的措施及其效果；采用正交设计试验方法进行天然砾石骨料沥青混凝土配合比设计，选定粗骨料最大粒径为19mm，拟定级配指数、填料用量、沥青用量为三个因素，，每个因素取3个水平值，以马歇尔稳定度、流值、试件的密度、孔隙率为考核指标，优选出最优配合比，并进行压缩试验、渗透试验、小梁弯曲试验、水稳定性试验、真空饱和浸水马歇尔试验和冻融劈裂试验，对天然砾石骨料在沥青混凝土心墙中的适用性进行了分析、评价；讨论了现行水工沥青混凝土试验规程中有关黏附性试验、水稳定性试验存在的若干问题，并依据试验结果提出了建议。所得主要结论如下：（1）五一水库天然砾石骨料主要由三种岩石组成，其中，75%为凝灰岩，呈中性；17%为斑状安山岩，呈酸性；8%为花岗岩，呈酸性。（2）按现行水工沥青混凝土试验规程规定的浸煮时间3min，无法明显区分出酸性骨料与碱性骨料在黏附性上的差别；当延长浸煮时间9min后，不同岩石骨料与沥青的黏附性差异才能较好的体现出来。因此，建议延长黏附性试验的浸煮时间，并提出与延长浸煮时间相匹配的黏结力等级评定的新标准。（3）骨料与沥青胶浆的黏附性不仅与骨料的岩性有关，而且与沥青混凝土中的填料性质有密切关系。不同类型的碱性添加料对不同岩性骨料黏附性的改善效果有所不同。对五一水库的天然砾石骨料而言，在沥青中掺入水泥对黏附性的改善效果最好。（4）优选出的五一水库天然砾石骨料沥青混凝土配合比为级配指数0.36、沥青用量6.4%、填料用量11%；水泥既作为填料又兼做改善骨料与沥青黏附性的措施。天然砾石骨料沥青混凝土相关性能试验结果表明采用水泥作为填料对于天然砾石骨料的黏附性具有明显的改善作用，天然砾石骨料沥青混凝土试验性能均符合规范要求，且可近似地达到白云岩骨料沥青混凝土的性能。（5）现行水稳定性试验不能准确评价水工沥青混凝土的水稳定性，建议进一步开展试验研究工作，探讨、寻求其他辅助方法来综合评价水工沥青混凝土的水稳定性。
[Abstract]:In order to study and discuss the applicability of natural gravel aggregate in asphalt concrete core wall, the adhesion properties between natural gravel aggregate and pure asphalt with different lithologic properties were studied by means of adhesion test in Wuyi Reservoir Project of Xinjiang. Cement, lime powder, dolomite powder and tuff powder were added to asphalt to make different asphalt paste, and the adhesion test of different lithologic natural gravel aggregate to different asphalt mortar was carried out. The measures to strengthen the adhesion between aggregate and asphalt and its effect are discussed, and the proportion of natural gravel aggregate asphalt concrete is designed by orthogonal design method. The maximum particle size of coarse aggregate is 19mm, and the gradation index and filler dosage are determined. The asphalt dosage is three factors, each factor takes three horizontal values, taking Marshall stability, flow value, density of the specimen, porosity as the assessment index, the optimum mix ratio is selected, and the compression test, permeation test, trabecular bending test are carried out. The applicability of natural gravel aggregate in asphalt concrete core wall was analyzed and evaluated by water stability test, vacuum saturated immersion Marshall test and freeze-thaw splitting test. This paper discusses some problems existing in the adhesion test and water stability test of hydraulic asphalt concrete in the current test code, and puts forward some suggestions based on the test results. The main conclusions are as follows:. 1) the natural gravel aggregate of Wuyi Reservoir is composed of three kinds of rocks, 75% of which are tuff, 17% of neutral rock are porphyry andesite, 8% of acid rock is granite, and 8% of acid is granite. (2) the difference in adhesion between acidic aggregate and alkaline aggregate can not be clearly distinguished by the soaking time of 3 mins in accordance with the current test code for hydraulic asphalt concrete, and when the soaking time is extended for 9 min, Therefore, it is suggested that the soaking time of the adhesion test should be prolonged, and a new standard for the evaluation of adhesion grade matching with the extended soaking time should be proposed. 3) the adhesion of aggregate to asphalt mortar is not only related to the lithology of aggregate, And it is closely related to the properties of fillers in asphalt concrete. The effect of different types of alkaline admixtures on the adhesion of different rock aggregates is different. For the natural gravel aggregate of Wuyi reservoir, Adding cement to asphalt is the best way to improve adhesion. The mixture ratio of natural gravel aggregate asphalt concrete selected from Wuyi Reservoir is 0.36 gradation index, 6.4asphalt content and 11filler content. Cement is used as filler as well as as a measure to improve the adhesion between aggregate and asphalt. The experimental results show that cement as filler can improve the adhesion of natural gravel aggregate obviously. The test performance of natural gravel aggregate asphalt concrete is in accordance with the requirements of the specification, and the performance of dolomite aggregate asphalt concrete can be approximately achieved. 5) the current water stability test can not accurately evaluate the water stability of hydraulic asphalt concrete. It is suggested that further research work should be carried out, and other auxiliary methods should be sought to comprehensively evaluate the water stability of hydraulic 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】：2014
【分类号】：TV641.41

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