高模量沥青混凝土制备工艺与PR.M的最优掺量研究

Study on Preparation Technology of High Modulus Asphalt Concrete and Optimal Dosage of PR.M

通过选择3种不同粗细集料比例的高模量沥青混凝土(High Modulus Asphalt Concrete,HMAC)级配类型,分别从高温、低温和水稳等方面对级配情况进行评价。结果表明,粗集料增加有助于形成骨架结构从而增强高温性能、冻融稳定性,减少车辙破坏和水损害;细集料的增加形成的绞结作用越强,能量消耗越大,表现出较高的破坏应变。结合室内混合料实验,从试件拌和方法、外掺剂干拌时间、拌和温度、拌和时间来确定施工拌和的施工工艺。采用干法作为拌和方式,其中混合料的拌和时间为石料与高模量剂干拌30 s,加入沥青拌和90 s,加入矿粉后拌和60 s,HMAC混合料拌和温度设定为175℃。故综合选择AC-20-Ⅱ级配进行施工建设,同时分析高模量剂的掺量(PR.M)对混合料的高低温、水稳性能的影响,确定了当掺量为0.5%时,沥青混合料的性能是最优的。

In this paper,three high modulus asphalt concrete(HMAC)gradation types with different coarse and fine aggregate ratios were selected to evaluate the gradation from the aspects of high temperature,low temperature and water stability,respectively.The results showed that the increase of coarse aggregate was conducive to the formation of skeleton structure,thus enhancing the high temperature performance and freeze-thaw stability,and reducing rutting damage and water damage.With the increase of fine aggregate,the stronger the binding effect was,the greater the energy consumption was and the higher the failure strain was.Combined with the indoor mixing experiment,from the specimen mixing method,dry mixing time of the admixture,mixing temperature,mixing time to determine the construction of mixing building construction technology.The dry method was adopted as the mixing method,and the mixing time of the mixture was 30 s dry mixing of stone and high modulus agent,90 s after adding asphalt,60 s after adding mineral powder,and the mixing temperature of HMAC mixture was set at 175℃.Therefore,AC-20-Ⅱgrade was selected comprehensively for construction.At the same time,the influence of the dosage of high modulus agent on the properties of high and low temperature and water temperature of the mixture was analyzed.It was determined that the performance of asphalt mixture was the best when the dosage was 0.5%.