2005 Volume 16 Issue 1 Pages 67-75
Over 30 years have passed since the expanding material for the concrete is developed in Japan, but it is hard to be said that the expanding material is widely used. In the inside where the durability of the concrete becomes a problem, the expansive concrete is being reexamined as one of the promising techniques which suppress the crack. In the meantime, expanding material has positively been used on the concrete product for the purpose of the chemical pre-stress introduction in order to raise the external pressure strength. Here, methods for coordination on new-model expanding material which added the performance which obtains early age strength was examined for the purpose of reduction of steam curing energy, improvement of mould rate of rotation and the prevention of crack. In addition, it was confirmed that the fast-strong performance of the new-model expanding material was well obtained as a result of applying to actual concrete product. As to this mechanism, it was considered that it was in early hydration heat build-up state of the new-model fast-strong type expanding material and hydration promotion of the alite of the cement.
