Structural performance of hybrid FRP laminates on concrete beams made with manufactured sand

ABSTRACT

Concrete, a vital material in construction, is facing challenges in enhancing its strength and durability. Researchers are exploring innovative approaches, such as using Fibre Reinforced Polymer (FRP) composites, to improve these properties. Structural flaws are often found during evaluations of existing buildings, especially older ones that may benefit from retrofitting. In this study, Manufactured sand was tested as a replacement for fine aggregate in concrete mixes to strengthen the mixes. The study utilized response surface methodology to predict the strength properties of sustainable Concrete mixes based on compressive strength. The flexure of reinforced concrete beams was evaluated using chopped strand mat (CSM) and glass-fiber reinforced plastic (GFRP) laminates. The study tested five RC beams using a 4-point bending configuration, with one beam serving as the control and the other four strengthened with FRP laminates. The results showed successful improvement in load-bearing capacity with GFRP + CSM laminates. However, thicker FRP sheets were not recommended as they can impact flexural strength. The GFRP + CSM enhanced beam achieved a 107% increase in ultimate load compared to the non-strengthened beams, according to experimental results. The strengthened beam had a greater rise load-carrying capability of 115 kN than the unstrengthen beam.

Keywords
Response surface methodology; Manufactured sand; composite materials; flexure; RC beams; strengthening