改性硅灰、粉煤灰对超高性能混凝土(UHPC)性能的影响  

Influence of Modified Silica Fume or Fly Ash on the Performance of Ultra-high Performance Concrete(UHPC)

作　　者：王东明 张世宇 姚苏皖 邹定华[1,2] WANG Dong-ming;ZHANG Shi-yu;YAO Su-wan;ZOU Ding-hua(School of Materials Science and Engineering,Henan Polytechnic University,Jiaozuo 454000,China;Henan Key Laboratory of Materials on Deep-Earth Engineering,Henan Polytechnic University,Jiaozuo 454000,China)

机构地区：[1]河南理工大学材料科学与工程学院,河南焦作454000 [2]河南理工大学河南省深地材料科学与技术重点实验室,河南焦作454000

出　　处：《混凝土与水泥制品》2021年第11期1-5,11,共6页China Concrete and Cement Products

基　　金：国家自然科学基金资助项目(U1604117)。

摘　　要：为降低超高性能混凝土(UHPC)黏度、提高工作性,采用硅烷(γ-缩水甘油醚氧丙基三甲氧基硅烷、十二烷基三甲氧基硅烷)对辅助胶凝材料(硅灰、粉煤灰)进行改性制备了自分散颗粒,并研究了其对UHPC工作性、抗压强度及微观结构的影响。结果表明:自分散颗粒降低了UHPC的黏度,提高了工作性;不同自分散颗粒对UHPC工作性的影响有较大差别,其中,粉煤灰和十二烷基三甲氧基硅烷制备的自分散颗粒效果最好;自分散颗粒抑制胶凝材料的早期水化,降低UHPC早期抗压强度;不同自分散颗粒对UHPC的28 d抗压强度影响也各不相同,采用粉煤灰和十二烷基三甲氧基硅烷制备的自分散颗粒提高了UHPC的28 d抗压强度,其他自分散颗粒降低了28 d抗压强度。In order to reduce viscosity and promote workability of fresh ultra-high performance concrete(UHPC),self-dispersing particles were prepared by using supplementary cementitious materials(fly ash and silica fume)modified by silanes(γ-glycidoxypropyltrimethoxysilan and dodecyltrimethoxysilane),and the workability,compressive strength and microstructure of UHPC were investigated.The results show that viscosity of fresh UHPC decreases,and the workability increases when self-dispersing particles are employed.The influence of different self-dispersing particles on workability is quite different.Self-dispersing particles prepared from fly ash modified by dodecyltrimethoxysilane show the highest effectiveness.Early age hydration of cementitious materials is inhibited by self-dispersing particles and compressive strength of UHPC decreases.Different self-dispersing particles have different effects on the 28 d compressive strength of UHPC.Self-dispersing particles prepared from fly ash and dodecyltrimethoxysilane increase the 28 d compressive strength of UHPC,while other self-dispersing particles reduce the 28 d compressive strength of UHPC.

关 键 词：超高性能混凝土 辅助胶凝材料 自分散颗粒 工作性 抗压强度 硅灰 粉煤灰 

分 类 号：TU528[建筑科学—建筑技术科学]