Drop-weight impact loading of polypropylene fiber reinforced concrete wall after one-year drying shrinkage

Abstract

Recent progress in finite element analysis aids the simulation of seismic vibration of an entire reinforced concrete (RC) building structure and indicates that drying shrinkage cracks affect seismic resistance performance. Polypropylene fiber-reinforced concrete (PFRC) is a promising material since the fibers will reduce the cracks and strains under drying shrinkage. This paper attempts to quantify the vibration characteristics of PFRC walls by means of a drop-weight test and finite element analyses. Four wall specimens having the same geometry and bar arrangement are prepared. After a one-year drying shrinkage period, the walls are subjected to impact loading of a constant collision velocity of 5 m/s, using a steel drop weight of 398.8 kg. Shear cracks are observed in the restrained wall made of plain concrete, while cracks are insignificant in the PFRC wall. Three-dimensional (3D) nonlinear finite element analyses are conducted to simulate all behaviors from drying shrinkage cracking up to the time of impact loading, and to estimate the vibration characteristics. The analysis results indicate that the polypropylene fiber content reduces the elongation of the natural period by an average of 13.7%.