محمود عدالتی

Most engineering projects specializing in buildings have structural study that take into account structural variable response and instantaneous deformations and frequently overlook long-term deformations, which, show a significant change and increase in deformation due to creep and shrinkage according to studies. As a result, this research concentrated on long-term deformations. Therefore, this thesis examined numerical models to investigate the structural response of simply supported beams models in two parts by considering finite elements procedure. The first part of models is (40 * 60) cm beam strengthen with reinforcing CFRP bars for a time 30, 60,90,180, 360, 420, 720, 1080, 1440 and 1800 days The span of beam is determined as 4 meters. The second part of the thesis considered three beam models with the dimensions of (150*300) mm, (200*350) mm, (300*450) mm for 5m span strengthened with reinforcing CFRP bars. Both parts of model were investigated for (30, 60, 90, 180, 360,420, 720, 1080, 1440 and 1800) days the effects of two concentered loads. Displacement, stress and strain are considered as structural indicator. The results show that the maximum value recorded about strain 57.3% and displacement 71% after 1800 days indicating the structural members continues to deform due to long term deflection creep and shrinkage.Second part of the thesis investigated the behavior of concrete beam with different cross section area. The results showed the maximum displacement in a beam with 300*450mm section. It was increased by 2.5% and 2.6% in the beams with 150*300 mm and 200*350 mm section after 5years, while the ratio will be increased at half time of loading between 300*450mm and 200*350 mm beams.