1. Assistant Professor, College of Civil Engineering, Hunan Univ., Changsha 410082, P.R. China (corresponding author).
2. Master, College of Civil Engineering, Hunan Univ., Changsha 410082, P.R. China.
3. Associate Professor, College of Civil Engineering, Hunan Univ., Changsha 410082, P.R. China.
4. Professor, State Key Laboratory of Silicate Materials for Architectures, Wuhan Univ. of Technology, Wuhan 430070, P.R. China.