为研究级配对水泥稳定煤矸石路用性能的影响，采用陕西省榆林地区小保当煤矿煤矸石作为研究对象，以逐级填充法和K法为基础，根据7 d无侧限抗压强度(UCS)结果优选出适宜的煤矸石粗细集料比例，并确定骨架密实型水泥稳定煤矸石集料的合理级配范围。在此基础上，进行劈裂强度(SS)、抗压回弹模量(CRM)、抗冻性能和收缩特性试验，并将所确定的级配的上限、中值和下限与规范推荐级配中值(GF)下制备的混合料的相关性能进行对比。研究结果表明，当煤矸石粗集料与细集料含量之比为40％～50％时，水泥稳定煤矸石形成骨架密实结构。水泥剂量为5％(质量分数)时，与GF级配试件相比，设计级配中值(TJ2)试件养护7、28、90 d的UCS分别提高38。03％、40。13％、34。93％(7 d UCS＞3。0 MPa)，养护28 d的耐冻系数提升30。13％，干缩系数减小35。85％。依所设计的级配制备的水泥稳定煤矸石的路用性能优于规范推荐级配。
Grading Optimization and Performance Study of Skeleton-dense Cement-stabilized Coal Gangue
To study the effect of grading on road performance of cement-stabilized gangue,this work utilized the coal gangue from Xiaobaodang coal mine in Yulin,Shaanxi Province as the research object.Based on the grade-by-step filling method and the K method,the optimal ratio of coarse/fine aggregates of coal gangue was determined according to the results of 7 d unconfined compressive strength(UCS),and the appropriate grading range of skeleton-dense cement-stabilized gangue aggregates was then obtained.On this basis,this work carried out relevant tests such as splitting strength(SS),compressive rebound modulus(CRM),frost resistance,and shrinkage characteristics,and made a comparative analysis on the aforementioned performance indexes of the mixtures prepared using the obtained grading range's upper limit,mean value,and lower limit with that prepared using the specification-recommended grading range's mean value(GF).The results showed that a coarse-fine aggregate ratio of coal gangue of 40％-50％could result in a skeleton-dense structure of the cement-stabilized coal gangue.When the cement dosage was 5％,compared with the GF grading specimen,the specimen with the proportion of mean value of the optimized grading(TJ2)exhibited 38.03％,40.13％and 34.93％higher UCSs after curing for 7,28,90 d,respectively(with 7 d UCS＞3.0 Mpa),and a 30.13％higher coefficient of frost resistance after curing for 28 d,as well as a 35.85％lower coefficient of dry shrinkage.It could be concluded that the cement-stabilized coal gangue prepared using the optimized grading is superior to the product with specification-recommended grading in road performance.
万方数据
维普
