再生混凝土粉制备轻质高延性地聚合物力学性能研究  

Study on the mechanical properties of lightweight engineered geopolymer composite preparedby recycled concrete powder

作　　者：孙留存 于龙 刘斌 SUN Liucun;YU Long;LIU Bin(China Green Development Investment Group,Beijing 100020,China)

机构地区：[1]中国绿发投资集团有限公司,北京100020

出　　处：《新型建筑材料》2025年第3期36-41,共6页New Building Materials

基　　金：上海市科学技术委员会自然科学基金项目(22dz1203104)。

摘　　要：利用再生混凝土粉(RCP)替代偏高岭土,结合硅灰共同作为前驱体,以粉煤灰漂珠作为轻质骨料,通过无水偏硅酸钠和水玻璃的激发作用,引入聚乙烯纤维作为增强材料制备轻质高延性地聚合物(LWEGC)。结果表明,RCP替代率不超过50%,即使粒径增大至100目,LWEGC仍具有理想的力学性能,其密度在1100~1200 kg/m^(3),抗压强度在20 MPa左右,抗拉强度在2.5MPa左右,拉伸应变达4.5%以上。0.7%的极低纤维掺量可以使得地聚合物体系产生优异的拉伸应变硬化性能。RCP的替代减弱了纤维-基体界面粘结,导致强度降低,但有利于促进多缝开裂能力。RCP的替代改变了地聚合产物种类,生成了水化硅铝酸钙(C-A-S-H)凝胶。This paper developed a lightweight engineered geopolymer composite(LWEGC),which was synthesized by using recycled concrete powder(RCP)to replace metakaolin and silica fume as the precursors,fly ash cenosphere as the lightweight aggregate,and polyethylene fiber as reinforcement,under the activation of anhydrous sodium metasilicate and waterglass.The results showed that the replacement of RCP with no more than 50%doping,even if the particle size increased to 100 mesh,can still achieve ideal mechanical properties.The density was kept in the range of 1100~1200 kg/m^(3),the compressive strength was up to 20 MPa,the tensile strength was more than 2.5 MPa,and the tensile strain was more than 4.5%.The extremely-low 0.7%fiber content was sufficient for the current geopolymer system to produce excellent tensile strain-hardening property.The replacement of RCP weakened the fiber-matrix interfacial bonding,thereby compromising the mechanical strength,but promoting the multi-cracking ability.The replacement of RCP changed the type of geopolymerization product,forming calcium silica-aluminate hydrate(C-A-S-H)gels.

关 键 词：再生混凝土粉 轻质 高延性地聚合物 聚丙烯纤维 力学性能 

分 类 号：TU528[建筑科学—建筑技术科学]