Four simply supported reinforced concrete (RC) beams were test experimentaly and analyzed using the extended finite element method (XFEM). This method is used to treat the discontinuities resulting from the fracture process and crack propagation in that occur in concrete. The Meso-Scale Approach (MSA) used to model concrete as a heterogenous material consists of a three-phasic material (coarse aggregate, mortar, and air voids in the cement paste). The coarse aggregate that was used in the casting of these beams rounded and crashed aggregate shape with maximum size of 20 mm. The compressive strength used in these beams is equal to 17 MPa and 34 MPa, respectively. These RC beams are designed to fail due to flexure when subjected to load as a two-point loading. To model the coarse aggregate realistically, the aggregate must distributed randomly according to the gradient and amount actually used in the mix design. This property is not found in the ABAQUS program that resulted in the use of an alternate program to represent the aggregate randomly. Next, the random representation of the aggregate were transfered to the ABAQUS program by using commands and instructions that the program can understand, to draw as a sketch. The comparison between experimental and numerical results showed that the XFEM is a good method used to simulate the non-smooth behavior in RC beams such as discontinuitiy and singularity. While a mesoscale model can be simulated the non-homogeneity in the concrete.
Bubbled slabs can be exposed to damage or deterioration during its life. Therefore, the solution for strengthening must be provided. For the simulation of this case, the analysis of finite elements was carried out using ABAQUS 2017 software on six simply supported specimens, during which five are voided with 88 bubbles, and the other is solid. The slab specimens with symmetric boundary conditions were of dimensions 3200/570/150 mm. The solid slab and one bubbled slab are deemed references. Each of the other slabs was exposed to; (1) service charge, then unloaded (2) external prestressing and (3) loading to collapse under two line load. The external strengthening was applied using prestressed wire with four approaches, wh
... Show MoreThis study conducted an analytical investigation on the behavior of concrete beams with openings reinforced by glass-fiber-reinforced polymer (GFRP) bars. In this study, five proposed beams reinforced by GFRP bars as flexural and shear reinforcement with openings were numerically examined. The variables were the opening orientation (vertical and horizontal) and the number of openings. These openings were located within the flexural zone of the proposed beams. The result shows that the vertical openings had a significant effect over the horizontal openings on reducing the ultimate load and increasing the mid-span deflection compared with the control beam. Moreover, the results showed t
This study conducted an analytical investigation on the behavior of concrete beams with openings reinforced by glass-fiber-reinforced polymer (GFRP) bars. In this study, five proposed beams reinforced by GFRP bars as flexural and shear reinforcement with openings were numerically examined. The variables were the opening orientation (vertical and horizontal) and the number of openings. These openings were located within the flexural zone of the proposed beams. The result shows that the vertical openings had a significant effect over the horizontal openings on reducing the ultimate load and increasing the mid-span deflection compared with the control beam. Moreover, the results showed t
This study investigates the impact of varying glass fiber-reinforced polymer (GFRP) stirrup spacing on the performance of doubly GFRP-reinforced concrete beams. The research focuses on assessing the behavior of GFRP-reinforced concrete beams, including load-carrying capacity, cracking, and deformability. It explores the feasibility and effectiveness of GFRP bars as an alternative to traditional steel reinforcement in concrete structures. Six concrete beams with a cross-section of 300 mm (wide) × 250 mm (deep), simply supported on a 2100 mm span, were tested. The beams underwent four-point bending with two concentrated loads applied symmetrically at one-third of the span length, resulting in a shear span (a)-to-depth (h) ratio of 2.
... Show MoreBackground: It has been well known that the success of mandibular implant- retained overdenture heavily depends on initial stability, retention and long term osseointegration this is might be due to optimal stresses distribution in surrounding bones. Types of mandibular implant- retained overdenture anchorage system and number of dental implants play an important role in stresses distribution at the implant-bone interface. It is necessary to keep the stresses below the physiologic tolerance level of the bone .since. And it is difficult to measure these stresses around bone in vivo. In the present study, finite element analysis used to study the stresses distribution around dental implant supporting Mandible implant retained overdenture Mate
... Show MoreThe influence and hazard of fire flame are one of the most important parameters that affecting the durability and strength of structural members. This research studied the influence of fire flame on the behavior of reinforced concrete beams affected by repeated load. Nine self- compacted reinforced concrete beams were castellated, all have the same geometric layout (0.15x0.15x1.00) m, reinforcement details and compressive strength (50 Mpa). To estimate the effect of fire flame disaster, four temperatures were adopted (200, 300, 400 and 500) oC and two method of cooling were used (graduated and sudden). In the first cooling method, graduated, the tested beams were leaved to cool in air while in the second method, sudden, water splash was use
... Show MoreCurrent design codes and specifications allow for part of the bonded flexure tension reinforcement to be distributed over an effective flange width when the T-beams' flanges are in tension. This study presents an experimental and numerical investigation on the reinforced concrete flanged section's flexural behavior when reinforcement in the tension flange is laterally distributed. To achieve the goals of the study, numerical analysis using the finite element method was conducted on discretized flanged beam models validated via experimentally tested T-beam specimen. Parametric study was performed to investigate the effect of different parameters on the T-beams flexural behavior. The study revealed that a significant reduction in the
... Show MoreThe influence and hazard of fire flame are one of the most important parameters that affecting the durability and strength of structural members. This research studied the influence of fire flame on the behavior of reinforced concrete beams affected by repeated load. Nine self- compacted reinforced concrete beams were castellated, all have the same geometric layout (0.15x0.15x1.00) m, reinforcement details and compressive strength (50 Mpa).
To estimate the effect of fire flame disaster, four temperatures were adopted (200, 300, 400 and 500) oC and two method of cooling were used (graduated and sudden). In the first cooling method, graduated, the tested beams were leaved to cool in air while in the seco
... Show MoreFor more than a decade, externally bonded carbon fiber reinforced polymer (CFRP) composites successfully utilized in retrofitting reinforced concrete structural elements. The function of CFRP reinforcement in increasing the ductility of reinforced concrete (RC) beam is essential in such members. Flexural and shear behaviors, ductility, and confinement were the main studied properties that used the CFRP as a strengthening material. However, limited attention has been paid to investigate the energy absorption of torsion strengthening of concrete members, especially two-span concrete beams. Hence, the target of this work is to investigate the effectiveness of CFRP-strengthening technique with regard to energy absorption of two-span RC
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