Durability study of glass fiber reinforced polypropylene sheet under simulated seawater sea sand concrete environment

Abstract

Glass fiber reinforced polypropylene (GFPP) composite materials have high potentials for civil engineering applications because of their abilities to be reshaped at construction sites and to be recycled and efficiently produced. In the present study, durability of a unidirectional GFPP sheet of 0.3 mm in thickness was investigated under seawater sea sand concrete (SWSC) environment up to six months at 25 and 60 °C, in terms of water uptake behaviour, longitudinal and transverse tensile strength. The results indicated GFPP sheet is very susceptible to the high temperature immersion in SWSC, leading to abnormally higher water uptake of 3.4% at 60 °C. In the same time, the longitudinal tensile strength retention after six month immersion is only 22.7% and 3.3% immersed in 25 and 60 °C SWSC. Immersed in water, GFPP sheet shows much better in the property retention, e.g., 79.3% in the longitudinal tensile strength and 84.0% in the transverse tensile strength at 60 °C for 6 months. At the same time, the saturated water uptake of GFPP sheet in 60 °C water is only 0.69%. Due to poor adhesion between glass fiber and non-polar polypropylene, poor resistance to SWSC corrosion of glass fiber and the rather thin thickness, the durability of the GFPP sheet is not high as expected.