Effect of Aggressive Environment on the Shear Strength of Hemp and Fiberglass Composite Joints

Abstract

Natural fiber composites (NFC) are growing due to the low cost, lightweight and environmentally friendly. In using the NFC in a structure, NFC is often being connected bonded with other materials such as fiberglass reinforced polymer composites. Adhesively bonded composites joint is suitable for connecting dissimilar materials. The paper investigates the effect of ageing in different ageing media on the shear strength of hemp fiber reinforced unsaturated polyester composites bonded to glass fiber reinforced unsaturated polyester composites joints. The joints were immersed in an aggressive environment (distilled water, alkaline/NaOH solution, acid/vinegar solution, and salt solution) up to 15 days. The results showed that after ageing for 7 days, the shear strength increased by 16%, 16% and 18%, respectively for aging media of distilled water, salt solution and acid solution, whereas aging in alkali solution (NaOH) for 7 days, the shear strength decreased by 29%. After aging time of 15 days in distilled water, salt solution alkaline solution (NaOH) the shear strength decreased by 21, 5 and 72%, while aging in acidic solution, the shear strength is still higher about 15% than the unaged specimens