磷石膏基胶凝材料和骨料制备C40高性能混凝土研究  

Research on preparation of C40 high performance concrete by phosphogypsum based cementitious material and aggregate

作　　者：马雪婷 丁庆军[2,3] 黄绍龙 李进辉[3] 刘晨曦 金帆 曹杰荣 曹玉贵 MA Xueting;DING Qingjun;HUANG Shaolong;LI Jinhui;LIU Chenxi;JIN Fan;CAO Jierong;CAO Yugui(Sanya Science and Education Innovation Park,Wuhan University of Technology,Wuhan 430000,China;bSchool of Materials Science and Engineering,Wuhan University of Technology,Wuhan 430000,China;Wuhan Textile University,Wuhan 430000,China;Hubei University,Wuhan 430000,China)

机构地区：[1]武汉理工大学三亚科教创新园,湖北武汉430000 [2]武汉理工大学材料科学与工程学院,湖北武汉430000 [3]武汉纺织大学,湖北武汉430000 [4]湖北大学,湖北武汉430000

出　　处：《混凝土》2024年第2期162-167,172,共7页Concrete

基　　金：三亚崖州湾科技城科技专项资助(SCKJ-JYRC-2022-15);国家自然科学基金(52378235)。

摘　　要：磷石膏基胶凝材料和骨料制备混凝土,可为高消纳磷石膏固废提供新思路;然而将磷石膏同时作胶凝材料和骨料制备混凝土的研究鲜有报道。为此研究了磷石膏基胶凝材料组成、骨料级配、砂率和水胶比对混凝土性能的影响规律,并通过XRD和SEM微观测试初探其机理。结果表明:采用5%的P·O 42.5级水泥、30%的磷石膏、65%矿粉制成的胶凝材料时,外掺0.5%NaOH+5%水玻璃和1%NaAlO_(2)复合激发剂,控制胶凝材料用量600 kg/m^(3),磷石膏破碎砂替代40%河砂,砂率41%,水胶比0.34,可制备出工作性能良好,初凝时间大于25 h,3 d、28 d及60 d抗压强度分别大于20.0 MPa、48.0 MPa和55.0 MPa,绝热温升低于35℃,60 d膨胀率大于180με的大掺量磷石膏基C40低温升微膨胀高性能混凝土。混凝土胶凝材料主要水化产物为AFt和C-S-H凝胶,胶凝浆体可穿透磷石膏骨料表面空隙,产生机械嵌锁作用使磷石膏骨料与胶凝浆基体结合更加紧密。The preparation of concrete by phosphogypsum based cementitious material and aggregate can provide a new idea for the high consumption of phosphogypsum solid waste.However,there are few reports on the use of phosphogypsum as cementing material and aggregate in the preparation of concrete.The effects of the composition,aggregate grading,sand rate and water-binder ratio on the properties of concrete based on phosphogypsum were studied,and the mechanism was investigated by XRD and SEM.The results show that when the cementing material made of 5%P·O 42.5 cement,30%phosphogypsum and 65%mineral powder is added with 0.5%NaOH+5%sodium silicate and 1%NaAlO2 composite activator,the dosage of cementing material is controlled by 600 kg/m^(3).Phosphypsum crushed sand replaces 40%river sand with sand rate of 0.41 and water-binder ratio of 0.34.The preparation has good working performance,initial setting time is greater than 25 h,compressive strength is greater than 20.0 MPa,48.0 MPa and 55.0 MPa for 3 d,28 d and 60 d,and adiabatic temperature rise is lower than 35℃.High volume phosphogypsum based C40 low-temperature micro-expansion high performance concrete with a 60 d expansion rate greater than 180με.The main hydration products of concrete cementing materials are AFt and C-S-H gels.The cementite can penetrate the surface void of phosphogypsum aggregate and produce mechanical interlock effect to bind phosphogypsum aggregate and cementite matrix more closely.

关 键 词：磷石膏 胶凝材料 骨料 混凝土 性能 

分 类 号：TU528.01[建筑科学—建筑技术科学]