Flexural Response and Failure Analysis of Solid and Hollow Core Concrete Beams with Additional Opening at Different Locations

Abstract

It is essential to make openings in structural concrete elements to accommodate mechanical and electrical needs. To study the effect of these openings on the performance of reinforced concrete (RC) elements, a numerical investigation was performed and validated using previous experimental work. The effect of the position and dimension of the opening and the beam length on the response of the beams, loads capacities, and failure modes was studied. The simulated RC beams showed different responses, loads capacities, and failure modes depending on the position and dimension of the opening. The transversal near support opening (TNSH) and longitudinal holes (LH) showed lower effects on the load capacities of the beams than the transversal near center opening (TNCH). The supreme reduction percentages of the load capacity (µu%) for beams with TNCH and TNSH were 37.21% and 30.34%, respectively (opening size = 150 × 150 mm2). In addition, the maximum µu% for beam with LH was 17.82% (opening size = 25% of the beam size). The TNSH with a width of less than 18.18% of the beam shear span (550 mm) had trivial effects on the beam’s load capacities (the maximum µu% = 1.26%). Although the beams with combined LH and TNCH or LH and TNSH showed different failure modes, they experienced nearly the same load reductions. Moreover, the length of the beam (solid or hollow) had a great effect on its failure mode and load capacity. Finally, equations were proposed and validated to calculate the yield load and post-cracking deflection for the concrete beams with a longitudinal opening.

Numerical Simulation of the Bearing Capacity of Variotropic Short Concrete Beams Reinforced with Polymer Composite Reinforcing Bars

“…In this regard, the results obtained by us in the design characteristics, which do not affect the change in concrete along the height of the variotropic section, compare favorably in the direction of acquiring advantages in relation to works such as [ 1 , 2 , 3 , 4 , 5 , 6 ]. Further, it should be noted that, in the aspect of comparing the approach to the differentiation of concrete over the section of the element, the work was performed for the first time and correlates only with studies [ 77 , 78 ], which were taken as the basis for numerical experiments.…”

“…This is in contrast to [ 3 ], where, due to activation by electric heating, the deflection of the bending elements increased. In [ 6 ], the deflection of reinforced concrete beams was regulated using additional holes in different places of solid and hollow elements. In this case, an increase in beam deflection was also observed [ 6 ].…”

“…In [ 6 ], the deflection of reinforced concrete beams was regulated using additional holes in different places of solid and hollow elements. In this case, an increase in beam deflection was also observed [ 6 ]. An important factor of the study is the possibility, due to the proposed technology of imparting a variotropic structure, to reduce the deflection of bending elements with fiberglass reinforcement (glass composite and basalt composite), which, in turn, significantly increases the deflection in comparison with steel reinforcement [ 8 , 28 ].…”

“…At the same time, precast concrete is still one of the most popular types of building products due to the fact that, in the factory, it is possible to clearly control the production process. Additionally, world science in the field of building materials science is developing new ways to improve compositions, recipes, technologies, design solutions and methods for calculating and designing building elements made of heavy concrete [ 1 , 2 , 3 , 4 , 5 , 6 ].…”

Experimental and Numerical Study on Flexural Behavior of Concrete Beams Using Notches and Repair Materials

“…In higherstrength concrete, beam brittle failure is caused by shear force and the development of a diagonal crack. The different types of openings reduce the stiffness of reinforced cement concrete (RCC) beams [8]. Dong et al (2002) [9] suggested that the load carrying capacity and stiffness of pre-cracked RC beams can be increased by providing carbon fiber-reinforced polymer (CFRP) at the tension side of the beam; the failure of the concrete cover and the debonding between the CFRP fabric and the concrete should also be investigated.…”