废砖粉改性MgO膨胀剂及其对砂浆性能的影响  

Modification of MgO Expansive Agent by Waste Brick Powder and Its Effect on Performance of Mortars

作　　者：唐族娟 邓敏 莫立武[1] 吕利明 刘光辉 

机构地区：[1]国家"江苏先进生物与化学制造协同创新中心",南京210009 [2]南京工业大学材料科学与工程学院材料化学工程国家重点实验室,南京210009

出　　处：《硅酸盐通报》2017年第12期3958-3963,共6页Bulletin of the Chinese Ceramic Society

基　　金：国家自然科学基金重点项目(51461135003);国家科技支撑计划课题(2011BAE27B01);国家重点研发计划(2016YFB0303601)

摘　　要：采用白云岩和废砖粉为原料,研究了煅烧制度对废砖粉改性MgO膨胀剂的影响(方镁石和贝利特为主要煅烧产物,故简称PB),并测定了PB对砂浆变形和强度的影响。结果表明,在950~1050℃内,煅烧制度对PB中MgO含量无明显影响,提高煅烧温度或延长保温时间均有助于降低PB的f-CaO和石英含量,增加β-C2S含量。掺PB砂浆试件的膨胀率随PB掺量的增加而增大,随着养护龄期的延长而增大。延长PB的保温时间或提高煅烧温度均使掺PB砂浆60 d之前的膨胀减缓。掺PB砂浆试件的抗压强度随PB掺量的增大而降低,随着养护龄期的延长,抗压强度降低百分数趋于减小。掺20%PB砂浆试件的28 d抗压强度降低百分数均小于10%;掺950℃煅烧1h制备的PB砂浆试件在60 d之前具有最大的膨胀率并且抗压强度降低百分数最小。MgO expansive agent（ MEA） was modified with dolomite and waste brick powder at different calcination systems（ The main products arepericlase and belite,which is referred to as PB）. The effect of PB on deformation and strengths of mortars was studied. Results show that calcination systems has no influence on MgO content in 950-1050 ℃,but increasing calcination temperature or extending holding time may reduce the content of f-CaO and quartz in PB. The expansion of mortars containing PB increases with increasing of the content of PB or curing age. The mortars containing PB produced at higher temperature for longer residence time expands at a relatively lower rate before 60 d. The compressive strength of mortars with PB decreases with increase of the content of PB. The reduction percentage of compressive strength of mortars decreases with extending curing age. The reduction percentage of compressive strength of mortars containing 20 wt% PB is less than 10% in 28 d. The mortars containing PB calcined at 950 ℃ for 1 h have the greatest expansion and the minimal reduction in strengths before 60 d.

关 键 词：改性 MGO膨胀剂 砂浆 膨胀性能 强度 

分 类 号：TU528[建筑科学—建筑技术科学]