开级配大粒径沥青碎石OLSM-25材料组成设计

Design of Materials Composition for Open- graded Large Stone Asphalt Mixes （ OLSM - 25 ）

为了解决半刚性基层沥青路面、旧水泥混凝土路面沥青加铺层结构以及刚性基层沥青路面共同存在的沥青面层反射裂缝问题，以及半刚性基层沥青路面的水损害问题，提出了采用开级配大粒径沥青碎石混合料（Open—graded Large Stone Asphalt Mixes，OLSM）作为裂缝缓解层的方法，以国内外OLSM参考级配为基础，应用变I法原理设计OLSM-25级配，结合空隙率（15％～20％）要求，提出OLSM-25推荐级配范围；以OLSM-25推荐级配的上限、中值、下限为1#～3#试验级配，采用析漏与飞散试验、大型马歇尔试验，综合稳定度、流值、空隙率、毛体积密度四个指标，最终确定1样～3群级配OLSM-25混合料的最佳沥青用量，为OLSM-25的配合比设计提供了参考依据。

In order to solve the problem of reflective cracking in the semi - rigid base asphalt pavement, the asphalt overlay on old concrete pavement and the rigid base asphalt pavement, as well as the water damaged problem of the semi - rigid base asphalt pavement, a method of using Open - graded Large Stone asphalt Mixes （ OL- SM） as the crack alleviating layer is proposed in the paper. On the basis of domestic and foreign reference gradation of OLSM, by using of the variable I principle, the gradation of OLSM - 25 is designed, and the recommended gradation range of OLSM-25 is put forward combined with the requirements of the porosity （15% to 20% ）, The upper, middle, and lower limit of recommended by using of the leakage and dispersion test, the value, porosity and bulk density, the optimum gradation range of 0LSM -25 are taken as 1#- 3# test gradations, large - scale Marshall test, and the four indicators of stability, flow asphalt content of 1 # -3 # gradations are ultimately determined, which provide a reference for the gradation design of OLSM -25.