Strengthening of reactive powder concrete T-beams with openings

In this research, the response of reactive powder concrete T-beams containing openings is studied. The experimental program involves testing of thirteen simply supported beams. The beams have the same dimensions, flexural and shear reinforcements. In this study, four three parameters have been studied: the shape of an opening (circular and square), a location of openings from the support (Lc/2, Lc/3, and Lc/4), and the internally strengthened around of opening using a deformed steel bar. The experimental results showed that the RPC T-beams with circular openings of diameter (110mm) with different locations (Lc/2, Lc/3 and Lc/4) have a flexural strength less than that solid beam by about (12%,35% and 41%) respectively. While for the RPC T-beams with square openings of dimension (100mmx100mm) with different locations (Lc/2, Lc/3, and Lc/4), the flexural strength is less than that solid beams by (10%,41% and 55%) respectively. In addition, it is found that the use of deformed steel bars as internal strengthening for the region around the openings has a significant effect on the overall behavior of beam. Where the ultimate flexural strength of these strengthened beams containing (circular and square) openings with different location increased by (9% to 66%) in comparison with the related un-strengthened beams with same openings. Also, this T-beams with openings showed increasing in deflection about (66.7% - 202%) compared with T-beam without openings at the same load. While for these strengthened T-beams with openings showed a reduction in deflection about (50% - 192%) compared with un-strengthened T-beam with openings.