Behavior of Recycled Aggregate Concrete Slab–Column Connection Strengthened by NSM GFRP Bars

Abstract

The mixture which contains self-compacting concrete (SCC), and recycled aggregates (RA) has a high workability and good handling which is used in heavy reinforcement locations. The application of glass fiber-reinforced polymer (GFRP) bars as an environmental substitute in construction helps for decreasing natural resource exhaustion and waste. On the other hand, the bars provide high strength, low ductility, and resistance to corrosion material when compared to steel bars. The combination of SCCRA with a GFRP reinforced concrete members develop an innovative RC member with highly functional characteristics. The structural behavior of slabs cast from self-compacting reinforced concrete mixed with recycled aggregates (SSRCRA) and reinforced with glass fiber-reinforced polymer (GFRP) bars by near-surface mounted (NSM) techniques have been investigated in this study. The research highlights the effect of number and the diameter of GFRP bars on the performance of SSRCRA slabs. Five SCC-RA slabs with dimensions of (1200 ×1200 ×100) mm, reinforced with different diameters and configurations GFRP bars are cast and tested. All specimens are exposed to a static load until failure. The results illustrate that SSRC slabs strengthened with NSM GFRP bars display superior performance compared to conventional concrete slabs, with significant improvements in ductility and load capacity. Particularly, this research demonstrates that increasing the number of GFRP bars enhances the load capacity by 31% and improves the ductility by 63% compared with control slab. Also, increasing of diameter of GFRP bars from 6 to 10 mm resulted in a reduction of the failure area and rising of load capacity with controlled deflection response. Overall, strengthening the SCC-RA slabs with NSM-GFRP bars leads to enhance stiffness, ductility, and structural performance.