Abstract: 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.

Key words: low clinker slag cement;particle size;ettringite;electrical resistivity