Controlling deflection in construction beams
The article by Dr. Mereen H. Fahmi Rasheed et al. is published in The Open Civil Engineering Journal, 2021
In civil engineering, flexural beams are used to control the effect of vibrations that can cause cracks to appear in surfaces (concrete slabs) and beams. This is particularly important in buildings that require high tensile strength and where the use of machinery can cause a lot of vibrations that can disturb structural integrity. One metric to determine the reliability of beams is the deflection value, which should be appropriately low relative to the structure the beams are used in. Engineering codes such as ACI codes include provisions for such values and there are a number of methods to calculate them. Deflection is altered practically by reinforcing the construction materials with concrete or steel.
In this review, engineers from Erbil Technical Engineering College, Erbil Polytechnic University, Erbil, Iraq, report on the effect of applied load intensity, steel reinforcement index amount as a ratio to the balancing reinforcement index (ρ/ρb), concrete strength (fc’ ) and beam width on the depth-span ratio of a beam of different types (simply supported, fixed ended, propped and cantilever). The study is mostly a theoretical work, and can be used as a basis for practical projects where beams are used.
The results in this report demonstrate that the effect of the balancing reinforcement ratio (ρ/ρb) was small on the depth-span ratio, and the required depth of the beam increased with increasing the applied distributed load value and decreased with increasing the concrete strength for all beam types. The findings were consistent for all beam types. The researchers suggest that existing ACI codes should be modified to include other parameters in addition to the balancing reinforcement ration, such as the applied distributed load, concrete compressive strength and cross section width. This helps engineers to control the parameters within the defined ACI limits by accounting for the effect of tension reinforcement area. The study has been published in The Open Civil Engineering Journal.
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