纤维水泥稳定碎石室内拌和工艺试验研究

发布时间：2018-05-02 21:55

本文选题：纤维水泥稳定碎石(FCSM) + 纤维分散性　；参考：《公路》2017年11期

【摘要】：掺加纤维可有效改善水泥稳定碎石(CSM)基层材料的抗裂性并提高其强度。在依托室内物理试验研究纤维水泥稳定碎石(FCSM)路用性能的工作中,重要环节之一是如何提高纤维在混合料中拌和分散均匀性,这将显著影响测试试件的性能稳定性。为此,通过拌和工艺试验,分析了影响纤维拌和分散效果的主要因素及其作用机理,获得了合理的FCSM室内拌和工艺,并通过强度稳定性试验分析进行了印证,从而提出了FCSM拌和工艺效果的辅助判定方法。结果表明,纤维分散均匀性易受集料干湿状态影响:干拌时,搅拌片产生的空气流动易使纤维飘浮在干燥集料表面并逐渐聚集结团;湿拌时,干纤维易吸附于湿混合料的表面。对拌和效果影响而言,投料次序影响更为显著,而延长拌和时间虽能起到提高纤维分散效果的作用,但拌和达到一定时间之后其效果增加并不明显。合理的FCSM室内拌和工艺应首先将全部集料与水泥进行干拌15s后再洒水搅拌15s,然后撒入纤维终拌60s。材料的强度变异系数可表征试件性能的稳定性,可将其作为FCSM拌和效果的辅助判定方法。成果可为FCSM路用性能室内物理试验研究工作奠定基础。
[Abstract]:The addition of fiber can effectively improve the crack resistance and strength of cement stabilized macadam (CSM) base material. In the research of road performance of fiber cement stabilized macadam (FCSM) based on indoor physical test, one of the important links is how to improve the uniformity of fiber mixing and dispersion in the mixture, which will significantly affect the performance stability of the test specimens. In this paper, the main factors affecting the effect of fiber mixing and dispersing and its mechanism are analyzed through mixing process test, and a reasonable FCSM indoor mixing process is obtained, which is verified by strength stability test. A method for determining the effect of FCSM mixing process is put forward. The results show that the dispersion uniformity of the fibers is easily affected by the dry and wet state of the aggregate: the air flow produced by the agitating sheet makes the fibers float on the surface of the dry aggregate and gradually agglomerate, and the dry fiber is easily adsorbed on the surface of the wet mixture when wet mixing. For the effect of mixing effect, the effect of feeding order is more significant, and prolonging mixing time can improve the effect of fiber dispersion, but after mixing for a certain time, the effect increase is not obvious. The reasonable FCSM indoor mixing process should first dry mix all aggregates with cement for 15 seconds, then sprinkle water for 15 s, then sprinkle the fiber into the finished mixing for 60 s. The strength coefficient of variation of the material can be used to characterize the stability of the properties of the specimen, and it can be used as an auxiliary method to judge the mixing effect of FCSM. The results can lay a foundation for the indoor physical test of FCSM road performance.
【作者单位】：深部岩土力学与地下工程国家重点试验室(中国矿业大学);中国矿业大学力学与土木工程学院;盐城市公路管理处;
【基金】：江苏省公路科学研究计划项目,项目编号2014Y02G
【分类号】：U414

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