关键词: 改性;MgO膨胀剂;砂浆;膨胀性能;强度

Abstract: 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.

Key words: modification;MgO expansive agent;mortar;expansion;strength