关键词: 石膏矿渣水泥;改性磷石膏;孔溶液;水化热;水化产物

Abstract: Gypsum slag cement was produced by mixing modified phosphogypsum ( 5％-25％ in mass ) , Portland cement clinker (15％in mass)and slag(60％-80％in mass).The compressive strength, heat of hydration , pH value of pore solution and hydration products of the gypsum slag cement were investigated .The results show that the compressive strength of the gypsum slag cement at 3 d and 7 d decreased with the incorporation of phosphogypsum .When the content of phosphogypsum reached 10％and 15％, the compressive strength at 28 d and 90 d surpass that of the ordinary portland cement .The pH value of the pore solution increased with the increase of age from 3 d to 90 d.At the same age , the pH value of the pore solution decreased , the occurring time of the exothermic peak increases , with the increase of phosphogypsum .The hydration products at the age of 28 d are mainly ettringite and calcium silicate hydrate , and the amount of hydration products reach the most with 15％of phosphogypsum .

Key words: gypsum slag cement;modified phosphogypsum;pore solution;heat of hydration;hydration product