1. Materials Technology Division, Railway Technical Research Institute, Tokyo, Japan.
2. Institute of Industrial Science, The University of Tokyo, Tokyo, Japan.
3. Infrastructure Technology Research Department, Technology Center, Taisei Corporation, Yokohama, Japan.
4. Concrete and Construction Materials Group, Kajima Technical Research Institute, Kajima Corporation, Tokyo, Japan.
5. Department of Civil Engineering, The University of Tokyo, Tokyo, Japan.