Study On Hygrothermal Ageing Of Glass And Basalt Fiber Based FRP Composites

Steels rust easily during the service of steel-concrete structures, which resultsin the performance degradation of the concrete, reduces safety of the structures,especially causes catastrophic accidents. The light-weight,high-strength and durableFRP composites are applied on the modern structures and considered to improve thedurability of structures and bearing performance effectively. As a new kind of structuralmaterial for Civil Engineering, it is not comprehensive to understand the long-termperformance degragation law and machanism of FRP composites in Civil Engineering,which affects the application in Civil Engineering of FRP safely, econamically and reliably.The long-term performance of Basalt Fiber Reinforced Polymer(BFRP)、Glass FiberReinforced Polymer and resin matix in distilled water or alkali solution is studied in thispaper by means of accelerated aging test and the specific contents and conclusions include:Water absorption and diffusion of resin matix in distilled water and alkali solutionconforms the Fick model. The higher the tempreture is, the bigger the equilibrium waterabsorption is. The erosion of water and chemical substances such as alkali to resin matixresults in the decline in mechanical properties. Water absorption makes resin matix plastic,which lowers the glass transition tempreture.Water absorption and diffusion of GFRP in distilled water conforms the Fick model.The higher the tempreture is, the bigger the equilibrium water absorption is. Waterabsorption and diffusion of BFRP in distilled water and alkali solution conforms theTwo-stage model. The higher the tempreture is,the more water sheets absorb. The hotand humid environment reduces the adhesion property between fiber and resin andmakes resin swell and degradate, which results in the decline of the machanical properties.At last, the influence of coating on water absorption and mechanical properties ofresin matix and FRP is studied in the paper. The result shows that the coating will lowerthe water absorption and improve the hygrothermal durability of FRP.