各因素对煅烧高硅磷石膏基水泥强度的影响

Impact of various factors on compressive strength of calcined high-silicon phosphogypsum-based cement

以磷石膏为研究对象,在磷石膏中加入粉煤灰和活性炭进行煅烧,制备成一种新型高强复合胶凝材料。通过正交实验研究煅烧温度、保温时间、活性炭掺量和水硬系数(HM)对抗压强度的影响,找出最优强度的条件。结果表明,当煅烧温度为1 200℃,保温时间为30 min,活性炭掺量为10%,HM值为1.3时,煅烧高硅磷石膏基水泥可以获得较高的早期和后期强度。试样在煅烧过程中,形成了C2S、C3S和C3A等活性矿物,在水化28 d后,形成了C-S-H凝胶、氢氧化钙和钙矾石等水化产物。

A new type of high-strength composite cementitious materials was prepared by calcining phosphogypsum with fly ash and activated carbon. This study explored the effects of temperature,retention time,activated carbon and hydraulic modulus（ HM） on compressive strength of calcined high-silicon phosphogypsum-based cement by orthogonal experiments. The results show that the early and later compressive strength of calcined high-silicon phosphogypsum-based cement are the highest when calcination temperature is 1 200℃ and retention time is 30 min,with 10% activated carbon and 1. 3 HM. A lot of active minerals,such as dicalcium silicate,tricalcium silicate,tricalcium aluminate are formed during the calcination. After hydration for 28 days,there are a large quantity of C-S-H Gel,calcium hydroxide and ettringite in the hydration products.