路面基层矿渣粉稳定全固废混合料力学性能试验研究

Experimental Study on Mechanical Properties of Pavement Base with All Solid Waste Mixture Stabilized by Mineral Powder

摘要:

为提高工业固体废弃物的利用率,以粒化高炉矿渣粉为结合料,研究矿渣粉稳定全固废(钢渣、煤矸石和回收粉)混合料路面基层的力学性能。采用均匀设计法,将钢渣、煤矸石和回收粉的掺量作为因素,7 d无侧限抗压强度、120 d抗压回弹模量以及120 d劈裂强度为目标响应值,设计6组试验配合比(质量比)展开试验,运用JMP软件对试验结果进行回归分析,建立不同材料掺量与三大力学性能指标间的数学模型,并借助Image J软件对混合料劈裂断面图像处理,从细观层面揭示混合料产生力学强度的主要原因。研究结果表明:混合料力学性能随钢渣掺量的增多而提高;回收粉掺量的增加会对混合料前期力学强度产生不利影响,然而,随着养护龄期的增长,后期力学强度随回收粉掺量增加呈现先提高后降低的变化趋势,故其掺量不宜超过35%;通过方差分析得出回归方程拟合程度较高,可为实际工程提供指导。

Abstract:

To enhance the utilization rate of industrial solid waste, a study was conducted on the mechanical properties of stabilized pavement base mixtures using granulated blast furnace slag powder as the binder, with the full solid waste (steel slag, coal gangue, and recycled powder) as the raw material. The uniform design method was employed, with the proportions of steel slag, coal gangue, and recycled powder as factors, and the 7-day unconfined compressive strength, 120-day compressive rebound modulus, and 120-day splitting strength as the target response values. Six sets of test mix ratios (mass ratios) were designed for the experiments, and the test results were analyzed using JMP software. A mathematical model was established between the different material proportions and the three mechanical performance indicators. The mixed material’s splitting fracture surface images were processed using Image J software to reveal the main reasons for the mechanical strength at the micro level. The research results show that the mechanical properties of the mixture increase with the increase in steel slag proportion; the increase in recycled powder proportion has an adverse effect on the initial mechanical strength of the mixture, but the later mechanical strength shows a trend of increasing first and then decreasing with the increase in recycled powder proportion, so its proportion should not exceed 35%. The regression equation obtained through variance analysis has a high fitting degree and can provide guidance for practical engineering.