缓凝剂对磷建筑石膏-普通硅酸盐水泥复合体系性能的影响及其机理研究  

Effect of Retarder on Properties of β-Hemihydrate Phosphogypsum-Ordinary Portland Cement Composite System and Its Mechanism

作　　者：马保国[1] 邬磊 陈偏 戚华辉 金子豪 杨琪 MA Baoguo;WU Lei;CHEN Pian;QI Huahui;JIN Zihao;YANG Qi(State Key Laboratory of Silicate Materials for Architectures,Wuhan University of Technology,Wuhan 430070,China)

机构地区：[1]武汉理工大学硅酸盐建筑材料国家重点实验室,武汉430070

出　　处：《硅酸盐通报》2022年第7期2411-2420,共10页Bulletin of the Chinese Ceramic Society

基　　金：河南省重大公益专项(201300311000);湖北省技术创新重大项目(2020BED025)。

摘　　要：磷建筑石膏(β-HPG)力学性能差,凝结硬化快,已有研究表明用普通硅酸盐水泥(OPC)替代部分β-HPG可改善其力学性能,但对此复合体系工作性能的调控作用及机理研究尚不明确。本文探讨了三种缓凝剂对β-HPG-OPC复合体系性能的影响,通过测试凝结时间和抗压强度来表征性能变化,通过分析水化热曲线、电导率曲线、XRD谱和SEM照片来讨论作用机理。研究结果表明,三聚磷酸钠(STPP)对复合体系基本无缓凝作用,蛋白质类SC缓凝剂(SC)和柠檬酸(CA)的缓凝作用均较好,其中SC对初凝时间的延缓作用较好,CA对终凝时间的延缓作用更佳。CA使二水石膏晶体的形貌发生改变,导致体系抗压强度显著降低;SC对二水石膏晶体的粗化作用使体系形成相对致密的微观结构体,对抗压强度影响较小。研究结果将为β-HPG-OPC复合体系工程应用提供重要参考,有助于推进β-HPG在工程中的高附加值利用。β-hemihydrate phosphogypsum(β-HPG)has poor mechanical properties and fast setting and hardening.Previous studies have shown that replacing part ofβ-HPG by ordinary Portland cement(OPC)can improve the mechanical properties of the composite system,but the regulation and mechanism on the workability of this composite system are still unclear.The effects of three retarders on the properties ofβ-HPG-OPC composite system were investigated in this paper.The macro-performance was characterized by setting time and compressive strength test.The mechanism was discussed by hydrating exothermic curve,conductivity curve,XRD pattern and SEM image.The results show that sodium tripolyphosphate(STPP)has no retarding effect on the composite system.Protein SC retarder(SC)and citric acid(CA)have excellent retarding effect on the composite system,among which SC has better retarding effect on the initial setting time,and CA has better delaying effect on the final setting time.The incorporation of CA changes the morphology of dihydrate gypsum,resulting in a significant decrease of compressive strength of the system.The coarsening effect of SC on dihydrate gypsum makes the system to form a relatively dense microstructure,which has little influence on the compressive strength.The research results will provide an important reference for the engineering application of theβ-HPG-OPC composite system,and help to promote the high value-added utilization ofβ-HPG in the engineering.

关 键 词：磷建筑石膏 普通硅酸盐水泥 复合体系 缓凝剂 凝结时间 抗压强度 缓凝机理 

分 类 号：TQ177.37[化学工程—硅酸盐工业]