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根据水泥混凝土中粗集料的作用,引入了集料填充比参数来表征粗集料的级配组成结构与集料颗粒之间的关系。以粒子干涉理论和颗粒填充理论为基础,参考体积法设计思想,提出了水泥混凝土粗集料嵌锁骨架结构级配组成设计方法,并编制了设计软件。根据试验工程水泥混凝土设计要求,应用设计软件确定了粗集料级配组成和嵌锁密实水泥混凝土设计配合比,并进行了混凝土性能试验验证。试验结果表明:应用设计软件直接确定的嵌锁骨架结构粗集料级配组成,比《公路水泥混凝土路面施工技术规范》(JTG F30—2003)推荐的级配范围下限偏粗,整体骨架结构更好;嵌锁密实水泥混凝土的坍落度为25 mm,满足10～30 mm的工作性设计要求;28 d弯拉强度为7.9 MPa,大于配制弯拉强度7.7 MPa,满足设计强度要求;应用快冻法试验得出的混凝土最大抗冻循环次数为250次,抗冻耐久性指数为49.2%,满足寒冷地区200次抗冻循环的要求。
According to the role of coarse aggregate in cement concrete, the parameters of aggregate filling ratio were introduced to characterize the relationship between aggregate composition and aggregate composition of coarse aggregate. Based on particle interference theory and particle filling theory, with reference to the design idea of volumetric method, a design method of compositional gradation of the embedded structure of the cement aggregate coarse aggregate was put forward and the design software was prepared. According to the design requirement of experimental cement concrete, the design mix of coarse aggregate gradation and interlocking cement concrete design was determined by design software, and the concrete performance test was carried out. The test results show that the coarse aggregate gradation of the interlocking skeleton structure determined directly by the design software is thicker than the lower limit of the grading range recommended by the Technical Code for Construction of Highway Cement Concrete Pavement (JTG F30-2003), and the overall skeleton structure is more The slump of embedded concrete is 25 mm, which meets the design requirement of 10-30 mm. The flexural strength at 28 d is 7.9 MPa, which is larger than the flexural strength at 7.7 MPa, which meets the design requirements. The maximum number of freeze-thaw cycles for concrete obtained by the freeze-thaw method was 250 times, and the anti-freeze durability index was 49.2%, meeting the requirements of 200 freeze-thaw cycles in cold areas.