2019 Volume 73 Issue 1 Pages 52-58
This paper discusses the influence of calcium nitrite and diethanol-propanolamine （DEIPA） on the strength and the hydration reaction of high volume slag cement （HVBFSC） containing 60％ blast furnace slag （BFS）, 5％ anhydrite and 30％ ordinary Porltand cement （OPC）. By adding of combination with calcium nitrite and DEIPA, the compressive strength of HVBFSC mortars are increased in each curing time. In this case, the initial hydration of BFS is accelerated and on the hydration of OPC is also promoted at late stage in the hydration of HVBFSC. The effect of calcium nitrite and DEIPA on the early hydration of HVBFSC is analysis by modified Tomosawa Motel of hydration. By adding of DEIPA or combination of DEIPA and calcium nitrite, diffusion coefficient in modified Tomosawa model is increased, water can be moved easily through the hydrated layer formed surround BFS compared with the case of no addition. Hydrated products are not changed by addition of these additives and CH, CSH and AFt and small amounts of AFm are produced. By adding of calcium nitrite and DEIPA, AFt is mainly produced.
