الفهرس | Only 14 pages are availabe for public view |
Abstract Reinforced concrete deep beams have many applications in buildings, bridges, offshore structures and foundations. The strain distribution along the depth of a section in a deep beam is non-linear. Therefore, The Bernoulli-Navier’s hypothesis for beams cannot accurately predict the behavior of deep beams since the assumption of ‘plane sections remain plane’ does not apply and therefore, the theory overestimates the flexure strength which is unacceptable. The main objective of the present experimental investigation was to study the difference in behavior between shallow and deep beams. The main studied variable was the span to depth ratio of the beam. An experimental program was conducted on seven simply supported reinforced concrete beams. All tested beams had the same width (b= 150 mm), span (L= 1400 mm) and longitudinal reinforcement ratio (μ= 0.35%). The span to depth ratio (L/d) was between 5.2 and 1.2. All beams were tested using mid span concentrated static loading. In the experimental results, the failure of beams with a span to depth ratio (L/d ≥ 3.4) occurred by flexure while beams with a span to depth ratio (L/d ≤ 2.5) failure occurred by shear. Also, it showed that the range between shallow and deep beams was between (L/d = 5.2) and (L/d = 3.4). Tested beams were theoretically analyzed using the strut and tie model and the results were compared to the experimental ones. ACI 318-14 method predicted better results than other models. However, it did not consider the effect of web reinforcement. |