In recent years, the use of blast furnace slag material is being focused as environmental loading reduction and sustainable construction. However, in general, autogeneours shrinkage of the concrete using much amount of GGBFS is large in compared to normal concrete, therefore risk of cracking should be cared. On the other hand, strength development speed of concrete at early stage will be decreasing as the dosage of GGBFS increases, even under steam curing condition. It can be considered these points will be significant disadvantage in both productivity and quality of precast concrete. So in this study, early strength type expansive agent and setting accelerator were used in combination. As a result, it was confirmed that compressive strength at early stage is obviously increased. And steam curing temperature can be reduced about 10 degrees, and also, 600×10-6 of restraint expansion was obtained.
The Influence of Curing Temperature on Hydrated Products of Blast Furnace Slag Cement and Its Porosity at the Early Stage of Hydration
