高掺矿物掺合料对复合胶凝材料强度、水化热和孔结构的影响

Effect of High Content Admixture on Strength,Hydration Heat and Pore Structure of Cementious Materials

现代混凝土用胶凝材料早期强度高,水化速度快,水化热高,制备混凝土体积稳定性不良。采用“低用量低比表面积水泥熟料,高掺量高比表面积矿物掺合料”的技术路线制备高掺量矿物掺合料复合胶凝材料。对其胶砂力学性能进行了研究,采用等温量热法对其水化放热进行了研究,通过MIP法对其微观孔结构特征进行研究。结果表明胶砂试件强度在早期强度降低不多的情况下,长龄期条件下强度能够持续增长,相应的水化热放热量和放热速率均有所降低,且随水化龄期的发展,从3 d到180 d,净浆的孔结构发生了显著变化,微孔(<20 nm)增长显著,大孔(>200 nm)数量明显减少。复合胶凝材料净浆的孔结构随龄期发展,大于200 nm的大孔数量减少明显,小于20 nm的微孔数量增长明显。

The volume stability is not good for the cementious materials used owned high early age strength,high hydration speed and high hydration heat.A new type cementious material on the technical route of"low dosage and low specific surface area clinker,high content and high specific surface area mineral admixture"was studied.The mechanical performance of the mortar specimen using the same fluidity mortar and the hydration heat with direct method and the microscopic pore structure with the method of MIP were studied.Results show that the early strength of mortar specimen reduced and the long term strength can grow.At the same time,the amount of the hydration heat and the speed were reduced.The pore structure of the low clinker cementious materials become more reasonable along with the development of the hydration ages.The macro-porous lager than 200 nm decreases obviously from 3 d to 180 d and the porous less than 20 nm increases greatly.