矿渣砂-水镁石纤维沥青混合料性能研究

Study on properties of slag sand and brucite fiber asphalt mixture

选用等质量的水镁石纤维及矿渣砂替代石灰岩机制砂以制备矿渣砂-水镁石纤维沥青混合料,并评价该混合料的高温抗车辙、低温抗开裂及抗水损害等路用性能,及探究矿渣砂的合理掺量。在深入研究矿渣砂与水镁石纤维等原材料特性的基础上,进一步研究它们共同应用于沥青混合料中的技术可行性与潜在优势;通过配合比设计,确定不同矿渣砂及水镁石纤维掺量组合下混合料的最佳油石比;通过开展高低温及水稳定性等室内试验,评价矿渣砂-水镁石纤维沥青混合料的路用性能。研究结果表明:不同时期生产的矿渣砂级配差距较大,使用时需先进行分档筛分再重组,以满足级配要求;矿渣砂不含有毒物质,不会对环境及人体身心健康造成危害;水镁石纤维能够改善矿渣砂沥青混合料的酸性环境,增强沥青与矿料之间的黏附能力;矿渣砂的掺入,会降低沥青混合料高低温性能及水稳定性能,掺量越大,则降低幅度越大;水镁石纤维的掺入,能改善矿渣砂沥青混合料的路用性能,当矿渣砂掺量为20%,水镁石纤维掺量为0.4%时,沥青混合料的水稳定性能与常规AC-13C沥青混合料的相当,而其高低温性能则明显优于常规AC-13C沥青混合料的。因此,使用矿渣砂等质量替代石灰岩机制砂,并添加水镁石纤维制备沥青混合料具备可行性和实用价值。

The slag sand-fiber asphalt mixture was prepared by using magnesite fiber and slag sand instead of limestone machine-made sand.The pavement performance of the mixture was evaluated,and the reasonable content of slag sand was explored high temperature rutting resistance,low temperature cracking resistance,and water damage resistance was measured.Based on the study of raw materials such as slag sand and brucite fiber,the characteristics of slag sand and brucite fiber and the feasibility of their joint application in asphalt mixture were evaluated.The optimum oil stone ratio of the mixture with different slag sand and brucite fiber content was determined.The road performance of slag sand-fiber asphalt mixture was evaluated by laboratory tests of high and low temperature and water stability.The grading of slag sand produced in different periods is very different,and it needs to be adjusted after grading and screening to meet the grading requirements.The slag sand does not contain toxic substances and will not cause harm to the environment and human physical and mental health.Brucite fiber can improve the acidic environment of slag sand asphalt mixture and enhance the adhesion ability between asphalt and ore.With the addition of slag sand,the high and low temperature stability and water stability of asphalt mixture are reduced to different degrees,and the greater the amount of addition,the more significant the decrease.With the addition of brucite fiber,the related road performance of slag sand asphalt mixture is improved.The water stability of asphalt mixture containing 20%slag sand and 0.4%brucite fiber is equivalent to that of conventional AC-13C asphalt mixture,and the high and low temperature performance is better than that of conventional AC-13C asphalt mixture.It is feasible to use slag sand as fine aggregate instead of limestone sand to prepare hydrogypsum fiber asphalt mixture,which has considerable economic and environmental benefits.