水泥粉煤灰稳定砖、混凝土再生碎石试验

Test of Brick and Concrete Recycled Aggregate Mixtures Stabilized by Cement and Fly Ash

为研究水泥粉煤灰稳定砖、混凝土再生碎石作为公路材料的适用性能,通过砖、混凝土再生碎石压碎值试验,设计了15组不同配比水泥粉煤灰稳定砖、混凝土再生碎石混合料,测试其击实特性和力学性能,分析砖、混凝土骨料掺比对级配碎石压碎值和击实指标的影响规律,以及水泥剂量和龄期对混合料力学性能的影响规律。结果表明:混合料压碎值满足最低等级公路要求时砖再生碎石掺量约为38%;随着砖再生碎石掺量增加,混合料的最佳含水率和最大干密度分别呈近似线性增大和减小趋势,相同水泥掺量混合料的无侧限抗压强度和间接抗拉强度基本呈线性减小的趋势,并建立了无侧限抗压强度和间接抗拉强度的关系模型。给出了不同等级公路水泥粉煤灰稳定砖、混凝土再生碎石的建议配比方案,为工业废渣利用提供了借鉴。

In order to study the applicable performance of brick and concrete recycled aggregate mixtures stabilized by cement and fly ash in roads construction,15 groups of mixtures with different ratios of cement and fly ash are designed,through brick and concrete recycled aggregate mixtures crushing value tests,to test their compaction characteristics and mechanical properties and to analyze the influencing law of brick and concrete recycled aggregate mixing ratio on the compaction value and compaction index of graded aggregates,as well as the influencing law of cement admixture and age on the mechanical properties of the mixtures.The results show that the crushing value to meet the requirements of the minimum grade highway brick recycled aggregates blending is about 38%.With the increase of brick recycled aggregates blending,the optimal moisture content and maximum dry density of the mixture are showing approximately linear increasing and decreasing trends respectively.The unconfined compressive strength and indirect tensile strength of the same cement blending mixture are basically linear showing decreasing trend,and the relationship model of unconfined compressive strength and indirect tensile strength is established.The proposed proportioning scheme of cement fly ash stabilized brick-concrete recycled aggregates for different grades of highway is given,which provides a reference for the utilization of industrial waste residues.