再生粗骨料混凝土改性增强技术试验研究

Experimental study on modification and reinforcement technologyof recycled coarse aggregate concrete

针对建筑垃圾随意堆放危害生态环境和人类健康的问题,对以建筑拆卸的混凝土块为原料制备的再生粗骨料混凝土的改性增强,可加大建筑垃圾再利用率并减少其产生的不良影响。分别采用物理和化学试验研究再生粗骨料混凝土改性增强特性,包括用微波加热混凝土试块进行改性及将水玻璃溶液浸泡改性后的再生骨料制备再生混凝土。通过混凝土立方体抗压强度测试,对比分析了微波加热改性混凝土以及水玻璃改性混凝土的力学性能。利用低场核磁共振技术(LF-NMR)分析了再生粗骨料改性混凝土的孔隙率及孔隙分布。结果表明:微波加热改性混凝土的抗压强度降低,而适宜浓度的水玻璃溶液浸泡可增强再生粗骨料强度,降低混凝土孔隙率。研究结果可为再生粗骨料混凝土改性增强技术的进一步发展提供参考。

Aiming at the problem that the random stacking of construction waste endangers the ecological environment and human health,the modification and reinforcement of recycled coarse aggregate concrete prepared from concrete blocks disassembled from buildings were put forward to increase the reuse rate of construction waste and reduce its adverse effects.The modification and strengthening characteristics of the recycled coarse aggregate concrete were studied by physical and chemical tests,including microwave heating concrete test block and soaking the recycled aggregate modified by water glass solution to prepare recycled concrete.Through the concrete cube compressive strength test,the mechanical properties of microwave heating modified concrete and water glass modified concrete were compared and analyzed.The porosity and pore distribution of recycled coarse aggregate modified concrete were analyzed by low field nuclear magnetic resonance(LF-NMR).The results showed that the compressive strength of microwave heating modified concrete was reduced,and the appropriate concentration of water glass solution can enhance the strength of recycled coarse aggregate and reduce the porosity of concrete.The research results can provide a reference for the further development of modified reinforcement technology of recycled coarse aggregate concrete.