Interfacial bonding behavior of steel fibers when using fine glass powder as partial substitution of silica fume/cement
Sihai Bao, Yafang Zhang, Congbo Li, Weijian Zhang, Ke Zeng
Abstract
The objective of this study is to investigate the influence of glass powder (GP) substitution levels on fiber-matrix interfacial behavior. The pullout load-slip response curves were obtained by conducting fiber pullout tests . The interfacial bond behavior of all specimens was quantitatively analyzed in details. From the XRD patterns and SEM images of matrix, the microstructure of all tested series was discussed. The results indicate that GP as partial substitution of cement/silica fume in ultra-high performance cementitious composite can help to improve the interfacial bond behavior. Among all tested series, the specimens with 20 % substitution level exhibited the largest energy absorption capacity . According to micro-properties of the matrix, it is found that the GP substitution level of 15 %–30 %, reduces the number of scattered pores significantly and more flocculent or fluffy C-S-H gels are produced. In addition, by involving meso-mechanics static equilibrium, the evolution of fiber pullout behavior with various GP substitution levels in different stages could be well simulated and predicted.