不同激发剂对废弃混凝土再生砖强度的影响研究

Study on the influence of different activators on the strength of waste concrete recycled brick

为实现废弃混凝土的资源化利用,以废弃混凝土机械破碎得到的再生微粉(<0.16 mm)及再生细骨料(0.16~4.75 mm)作为研究对象,利用XRF、SEM、XRD等方法对其物理性能、化学成分、颗粒形貌、物相组成等进行了测试分析。采用压制成型方法,利用废弃混凝土再生材料制备再生砖,选用Ca(OH)2、CaSO4·2H2O、CaCl23种激发剂提高再生砖的强度。试验结果表明:CaSO4·2H2O对再生砖强度提升效果最好,当CaSO4·2H2O掺量为5%,再生细骨料及再生微粉总用量为75%时,制备的再生砖28 d抗压强度能达到MU20等级要求。

In order to realize the recycling utilization of waste concrete,recycled micro powder(<0.16 mm)and recycled fine aggregate(0.16~4.75 mm)obtained from mechanical crushing of waste concrete were studied.XRF,SEM,XRD and other analysis and testing methods were used to study its physical properties,chemical composition,particlemorphology and phase composition.By pressing molding method,the waste concrete recycled material was used to prepared the recycled brick.Ca(OH)2,CaSO4·2H2O and CaCl2 were selected as activators to improve the strength of the recycled brick.The results show that CaSO4·2H2O has the best effect on the strength improvement of the regenerated brick.When CaSO4·2H2O is added in 5%,and the total amount of recycled fine aggregate and recycled fine powder is 75%,the strength of the regenerated brick can reach MU20 grade in 28 days.