Basalt Textiles/Grids for Strengthening Existing Concrete Structures: Research and Applications

Basalts fiber is a green, healthy and environmental fiber material, which has emerged in recent years as a new member of the non-metallic fiber family. Basalt fibers can be made in the continuous forms of uni-directional dry fiber sheets, fiber textiles or grids (which are pre-impregnation with resins) to provide flexibility for different applications. This presentation provides a summary of the authors’ recent efforts in using linear elastic basalt fiber textiles/grids together with ductile engineering cementitious composites (ECC) to form a tension-stiffening material for the structural strengthening of existing concrete structures. The combined use of basalt textile/basalt fiber-reinforced polymer (BFRP) grids and ECC facilitates improved moisture resistance, fire resistance as well as the debonding capacity as compared to the conventional externally bonded FRP methods. The research work introduced here included the direct tensile behaviour of BFRP grid-reinforced ECC coupons and BFRP-ECC flexurally strengthened RC beams, BFRP-ECC shear strengthened RC beams and BFRP-ECC confined RC columns. The flexural performance of fire-damaged RC slabs strengthened with BFRP textile-reinforced ECC was also investigated. Some practical applications of the above mentioned BFRP-ECC technology in the strengthening of existing infrastructures, particular the in bridge structures, are herein reported.