基于不同粒径分布的低熟料矿渣水泥水化特征和孔结构特性

低熟料矿渣水泥(LSC)是一种水泥熟料用量低,主要由粒化高炉矿渣和石膏组成的水硬性胶凝材料.本文研究水泥不同粒径分布(对应比表面积分别为358 m2/kg、450 m2/kg和516 m2/kg)对低熟料矿渣水泥的抗压强度、电阻率和水化热、水化产物、孔结构的影响.结果表明,当比表面积从358 m2/kg增加到450 m2/kg可以提高低熟料矿渣水泥浆体的抗压强度,当从450 m2/kg增加至516 m2/kg时,强度提高甚微.低熟料矿渣水泥主要的水化产物是钙矾石和水化硅酸钙,增加水泥细度导致放热速率明显加快,电阻率变化曲线的下降段持续时间明显缩短,因而会产生更多的钙矾石.水泥细度增加,浆体的凝胶孔的体积分数增大,大孔减少,进一步提高浆体的密实度.

Characteristics of Hydration Products and Pore Structure of Low Clinker Slag Cement Based on Different Size Distribution

Low clinker slag cement (LSC) is a hydraulic cementitious material which consist mainly of granulated blastfurnace slag, calcium sulphateand sometimes contain a little additional constituents and low amount of cement clinker.The purpose of this paper was investigating the influence of cement fineness on the hydration process and microstructural, mechanical and physical properties of LSC paste.The compressive strength, heat of hydration and electrical resistivity, hydration product and pore structure, were studied on the LSC pastes with specific surface area of 358 m2/kg, 450 m2/kg and 516 m2/kg, respectively.The results show that the compressive strength of LSC paste can be improved by increasing the cement fineness from 358 m2/kg to 450 m2/kg.But the strength can not be obviously improved when the cement fineness was further increased from 450 m2/kg to 516 m2/kg.The main hydration products are ettringite and hydrated calcium silicate.Both of heat release rate and electrical resistivity were accelerated when the cement fineness was increased.This indicates that the hydration rate of LSC paste was improved with the increase of cement fineness.The volume fraction of gel pore was increased with the increase of cement fineness for the hardened LSC pastes.