Shear behavior of high-volume fly ash self-compacting concrete (HVFA-SCC) T-beams strengthened with carbon fiber reinforced polymer (CFRP)

Fly ash from coal combustion waste was utilized in this study as a key component in self-compacting concrete (SCC), specifically high-volume fly ash self-compacting concrete (HVFA-SCC) with 50% fly ash content, strengthened using carbon fibre reinforced polymer (CFRP) wrap-type sheets. The HVFA-SCC T-beams had dimensions of 120 mm web width × 240 mm web height, 80 mm flange thickness, and 440 mm flange width, with a total length of 3000 mm. There were three types of beams made in this study. The first type was HVFA-SCC T-beam without CFRP. The second type was strengthened by CFRP with the width of 100 mm and the spacing of 150 mm. The third type was the HVFA-SCC T-beam strengthened by CFRP with the width of 250 mm and the spacing of 300 mm. The beams were tested under monotonic two-point loading. The result showed that all beams were failure controlled by flexural failure. There was no shear failure occurred because the shear capacity of the beams exceeded the flexural capacity of the beams. These results confirm that the structural failure of the tested beams was governed by a flexural-controlled failure mechanism, rather than by shear. This is due to the actual concrete compressive strength exceeded the design compressive strength, increasing the concrete shear strength, leading to flexural failure in the beam