A Study on Chemical Ageing of Composite Ribbed GFRP Bars under Load

Here we explored the chemical durability of glass fiber-reinforced polymer (GFRP) bars under load. Three batches of ribbed GFRP bar specimens were fabricated using binder matrices: ED-22+isomethyltetrahydrophthalic anhydride (iso-MTGFA), ED-22+Ethal-450 and NPPN-631+ iso-MTGFA. As the reinforcing filler, we used an EC17 glass roving (for all the specimen batches). The specimens of each batch were aged in a 1 N alkaline NaOH solution at 60 °C for 2000 hrs. The ageing was performed under a 300 MPa load (30% of the failure stress). The tensile strength of the specimens from each batch following ageing was measured. The tensile test results demonstrated that that the strength loss of the specimens following chemical ageing was 58.9% for batch 1 based on ED-22+iso-MTGFA, 6.6% for batch 2 based on ED-22+Ethal-450, and 33.6% for batch 3 based on NPPN-631 + iso-MTGFA. The specimens of batch 2 based on ED-22+Ethal-450 exhibited the greatest resistance to the NaOH alkaline solution (a strength loss of 6.6%).