UV accelerated aging and sewage sludge ash particle effects on mode I interlaminar fracture properties of glass fiber/epoxy composites

Fiber-reinforced polymer composites under severe environmental conditions including humidity, high temperatures and UV radiation have been recently used in space, automotive, construction, wind turbines and marine industries. Glass fabric-reinforced epoxy composites (GFRPs) have high sensitivity to moisture and temperature of ultraviolet (UV) accelerated aging that resulted in a reduction of mechanical and toughness properties. This paper attempts to modify GFRPs by incorporating sewage sludge ash (SSA) waste particle, to enhance the composite resistance against UV aging. The behavior of interlaminar fracture toughness of mode I for aged and unaged specimens was investigated using a double-cantilever beam (DCB) test with the effect of SSA particle inclusion. The results revealed that the deterioration of interlaminar fracture toughness values was owing to expose to 1000 h of UV accelerated aging. However, these values were improved with the incorporation of SSA. The fracture toughness of mode I reached to peak value due to SSA inclusion of 10% (wt) with an increment of 14.3%, compared to the aged unfilled composite, which this peak value was decreased due to UV aging by 1.7% compared to the corresponding unaged composite. The degradation level of delamination energy was increased at high SSA content to reach 26.8% for aged GFRP specimen with SSA content of 20% (wt) compared to the corresponding unaged specimen. The mass variation of DCB composites was decreased gradually because of 1000 h of UV aging and the minimum weight loss was 1.25% obtained at SSA inclusion of 5% (wt). The water absorption of the composites was slightly increased with the inclusion of SSA particle. SEM and optical images were taken to observe the adhesion behavior within the glass/SSA/epoxy system.