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。
Mixing fiber can effectively improve the crack resistance and strength of the cement stabilized macadam （CSM） base material. How to improve the uniformity of fiber in mixture is one of important steps in the pavement performance of fiber-cement stabilized macadam （FCSM） experiment, which will significantly impact the performance of the test specimen stability. The main factors affecting the dispersion effect of fiber and its mechanism are analyzed by mixing process test. The reasonable FCSM mixing process is obtained and verified by strength stability test, the auxiliary judgment method for FCSM mixing process is put forward. The results show that the dispersion of fiber is apt to be affected by the dry and wet state of the aggregates. The air flow caused by the stirring film is apt to float the fiber on the surface of the dry aggregate and gradually accumulate the agglomerates when the dry mixing. The dry fiber is apt to adsorbed by the surface of the wet mix. The order of feeding has remarkable effect for mixing effect. The effect of fiber mixing can be improved by prolongation of the mixing time, but this effect can be ignore after a certain time. In the reasonable FCSM mixing process, all of the aggregate should be dry mixed 15s with cement, then sprinkle water for 15s, sprinkle into the fiber for 60s in the end. The coefficient of variation of the strength of the material can be used to characterize the stability of the specimen, which can be used as an auxiliary judgment method for FCSM mixing effect. The results has laid the foundation for the research of FCSM road performance indoor physics experiment.
出处
《公路》
北大核心
2017年第11期19-24,共6页
Highway
基金
江苏省公路科学研究计划项目,项目编号2014Y02G
