废旧陶瓷内养护混凝土性能研究分析

Research and Analysis on Performance of Concrete Curing in Waste Ceramics

摘要:

针对空心板铰缝混凝土收缩易开裂的问题，探索利用废弃陶瓷作为内养护材料，以提升其抗裂性能，实现废弃物资源利用。为此，以不同替代率将废弃陶瓷粗骨料替代天然花岗岩粗骨料，制备自密实混凝土试件，并测试其工作性、抗压强度、干燥收缩及新旧混凝土黏结劈拉强度。研究结果表明，当废弃陶瓷替代率不大于20%时，混凝土工作性能满足规范要求，28 d抗压强度因内养护作用而略高于普通自密实混凝土，干燥收缩显著降低，且新旧混凝土界面劈拉强度提升22.5%；当废弃陶瓷替代率超过30%后，因骨料表面釉质影响界面黏结，导致混凝土力学性能下降。综合结构性能、环保与经济性要求，20%废弃陶瓷替代率为最优方案，可在保证强度的同时有效抑制混凝土收缩，适用于空心板铰缝工程。

Abstract:

In response to the issue of shrinkage-induced cracking in concrete of hollow slab hinge joints, the use of waste ceramics as an internal curing material is explored to enhance its crack resistance and realize the utilization of waste resources. Therefore, the self-compacted concrete specimens are prepared by replacing natural granite coarse aggregates with waste ceramic coarse aggregates at different substitution rates. And the workability, compressive strength, drying shrinkage and bond splitting tensile strength between old and new concrete are tested. The results show that when the replacement rate of waste ceramics does not exceed 20%, the working performance of concrete meets the specification requirements. Due to the internal curing effect, the 28-day compressive strength is slightly higher than that of ordinary self-compacting concrete, the drying shrinkage is significantly reduced, and the split tensile strength at the interface between new and old concrete increases by 22.5%. When the replacement rate of waste ceramics exceeds 30%, the interfacial bonding is affected by the glaze on the surface of the aggregates, resulting in a decline in the mechanical properties of the concrete. By synthesizing the structural performance, environmental protection and economic requirements, a 20% replacement rate of waste ceramics is the optimal scheme, which can effectively suppress the shrinkage of concrete while ensuring its strength and is suitable for hollow slab hinge joint engineering.