公路路面低成本水泥稳定基层材料优化及性能研究

发布时间：2018-01-17 03:24

  本文关键词：公路路面低成本水泥稳定基层材料优化及性能研究　出处：《长沙理工大学》2015年硕士论文　论文类型：学位论文

  更多相关文章： 路面 水泥稳定基层 设计 性能 粉煤灰

【摘要】：公路路面基层作为路面结构的主要承重层,其性能的优劣对整个路面结构的稳定性起着决定性的作用。目前国内外许多研究将大剂量水泥应用到路面基层的稳定改良中,从而改善了基层力学性能,获得了较好的路用效果,但是也出现了许多问题。为响应我国“两型社会”建设,在确保公路路面性能的基础上,借鉴国内外先进的研究方法,针对低剂量水泥及固体工业废渣用于公路基层稳定材料进行研究,旨在一定程度上改善路面基层材料相关性能,降低工程成本及环境污染,并根据实际工程应用对其使用效果及经济效益进行评价,获得主要结论如下:(1)不同配合比的击实试验结果表明,基于相同稳定方法,随着水泥含量的增加,水泥粉煤灰稳定土的最佳含水量与最大干密度均随之增加;5%水泥掺量的纤维稳定土的最佳含水量为17.3%,干密度为1.749g/cm3;水泥粉煤灰稳定碎石的最佳含水量随着粉煤灰掺量的增加而增加,最大干密度呈先增后降趋势。(2)水泥粉煤灰稳定类材料试验表明,在相同的养护龄期条件下,水泥含量与粉煤灰掺量对无侧限抗压强度均有一定的改善;且水泥粉煤灰稳定碎石的抗压强度随着脱硫石膏与粉煤灰复合比例的升高而增加,与1:1复合比例相比,1:2、1:3复合比例的7d抗压强度分别增加5%、10%。劈裂强度试验结果显示,粉煤灰的掺入对其改善效果明显,可增加混合料的劈裂强度。根据破坏形式分析发现,粉煤灰能很好地参与并促进掺加材料之间的火山灰反应,提高整体结构的密实度。(3)纤维水泥稳定土的试验表明,纤维掺量与长度对稳定土的强度有一定的改善,纤维掺量与长度在一定的范围内,可增加基体的抗压及劈裂强度。与纤维掺量为0‰、2‰、4‰相比较,6‰掺量的纤维水泥稳定土具有显著的7d抗压强度优势;结合其破坏形式分析发现,聚丙烯纤维可显著提高稳定土基体的性能。(4)龄期对水泥稳定类材料抗压强度的影响分析发现,养生早期基层材料的强度增长较快,而后期强度增长速率较慢。综合比较分析不同配合比改良基层材料的路用效果及工程经济,粉煤灰及脱硫石膏的掺加,不仅使得混合料的强度等性能满足实际工程需要,而且具有良好的经济效益和环保效应。
[Abstract]:Highway pavement base is the main bearing layer of pavement structure. The quality of its performance plays a decisive role in the stability of the whole pavement structure. At present, many researches at home and abroad have applied large amount of cement to the stability improvement of the pavement base, thus improving the mechanical properties of the base. In order to respond to the construction of "two-type society" in our country, on the basis of ensuring the performance of highway pavement, the advanced research methods at home and abroad are used for reference. In order to improve the performance of pavement base material and reduce the engineering cost and environmental pollution, the low dose cement and solid industrial waste residue used in road base stabilization material were studied in order to improve the performance of road base material to a certain extent. According to the practical engineering application, the application effect and economic benefit are evaluated, and the main conclusions are as follows: 1) the results of compaction test with different mix ratios show that the method is based on the same stability method. With the increase of cement content, the optimum moisture content and maximum dry density of cement fly ash stabilized soil increased. The optimum water content and dry density of fiber stabilized soil with 5% cement content are 17.3g / cm ~ (-3) and 1.749 g / cm ~ (-3) respectively. The optimum moisture content of cement fly ash stabilized macadam increased with the increase of fly ash content, and the maximum dry density increased first and then decreased. Under the same curing age, the content of cement and the content of fly ash can improve the unconfined compressive strength. The compressive strength of cement fly ash stabilized macadam increased with the increase of the ratio of desulphurized gypsum and fly ash, and compared with the ratio of 1: 1 / 1, the compressive strength of cement fly ash stabilized macadam increased by 1: 2. The compressive strength of 1: 3 composite ratio for 7 days increased by 5% and 10% respectively. The results of splitting strength test showed that the addition of fly ash had obvious effect on its improvement. According to the analysis of the failure form, the fly ash can participate in and promote the pozzolanic reaction between the materials. The experiment of improving the compactness of the whole structure shows that the fiber content and length have certain improvement on the strength of the stabilized soil, and the fiber content and length are in a certain range. The compressive strength and splitting strength of the matrix can be increased. Compared with the fiber content of 0 鈥，

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