Tikrit Journal of Engineering Sciences (Mar 2019)
Repairing of Reactive Powder Concrete T-Beams Containing Web Opening by CFRP Strips
Abstract
In modern buildings, transverse openings are often used for the purpose of supplying and service pipes. The presence of the openings in the concrete beams leads to the formation of cracks around the openings due to the stresses concentration in a small area above and below the opening. The repairing, maintenance, and upgrading of structural members, are one of the most pivotal problems in civil engineering applications. In this research, an experimental work is conducted to study the behavior of the reinforced RPC T-beams that contain openings and to repair this beams using CFRP strips. The Experimental program of the present study includes two parts, the first part includes testing of seven reinforced reactive powder concrete RPC T-beams, which casted and tested, one beam is without opening as a reference beam and the rest, were provided with an opening. These beams are divided into two groups. The first group was used to study the effect of the openings shape (circular and square) and the second group was used to study the effect of the openings locations, which consists of three locations (Lc/2, Lc/3 and Lc/4). These are measured from the support center to the openings center. The second part includs repairing all beams in the first part using carbon fiber polymer. The test results indicated that the presence of openings in the beams web caused a reduction in the reinforced RPC T-beams ultimate load carrying capacity with about (10-55)%. Also leads to an increase in deflection compared to the control beam before repairing at the same loading. Studying the shape effect showed that the beams with square openings have average ultimate load carrying capacity lower than 36% compared with the control beams, While beams which contain circular openings have average ultimate load carrying capacity lower than 29%. From the test results, it could be concluded that the presence of the openings in the shear region led to a decrease in ultimate load carrying capacity about 38% to 49% for opening of opening at (Lc/3 and Lc/4) respectively. While the presence of openings in the flexural region led to a decrease in the ultimate load carrying capacity rate of 11%. As far as the part of the study related to repairing, it was found that the average ultimate load carrying capacity for repairing beams was 103% compared with the not repaired beams.
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