Numerical studies on load-carrying capacities of notched concrete beams subjected to various concentrated loads

2004 ◽  
Vol 18 (3) ◽  
pp. 173-180 ◽  
Author(s):  
Zihai Shi ◽  
Masaki Suzuki
Author(s):  
Paolo Foraboschi

Renovation, restoration, remodeling, refurbishment, and retrofitting of build-ings often imply modifying the behavior of the structural system. Modification sometimes includes applying forces (i.e., concentrated loads) to beams that before were subjected to distributed loads only. For a reinforced concrete structure, the new condition causes a beam to bear a concentrated load with the crack pattern that was produced by the distributed loads that acted in the past. If the concentrated load is applied at or near the beam’s midspan, the new shear demand reaches the maximum around the midspan. But around the midspan, the cracks are vertical or quasi-vertical, and no inclined bar is present. So, the actual shear capacity around the midspan not only is low, but also can be substantially lower than the new demand. In order to bring the beam capacity up to the demand, fiber-reinforced-polymer composites can be used. This paper presents a design method to increase the concentrated load-carrying capacity of reinforced concrete beams whose load distribution has to be changed from distributed to concentrated, and an analytical model to pre-dict the concentrated load-carrying capacity of a beam in the strengthened state.


2020 ◽  
Vol 38 (5A) ◽  
pp. 669-680
Author(s):  
Ghazwan K. Mohammed ◽  
Kaiss F. Sarsam ◽  
Ikbal N. Gorgis

The study deals with the effect of using Slurry infiltrated fiber concrete (SIFCON) with the reinforced concrete beams to explore its enhancement to the flexural capacity. The experimental work consists of the casting of six beams, two beams were fully cast by conventional concrete (CC) and SIFCON, as references. While the remaining was made by contributing a layer of SIFCON diverse in-depth and position, towards complete the overall depths of the built-up beam with conventional concrete CC. Also, an investigation was done through the control specimens testing about the mechanical properties of SIFCON. The results showed a stiffer behavior with a significant increase in load-carrying capacity when SIFCON used in tension zones. Otherwise high ductility and energy dissipation appeared when SIFCON placed in compression zones with a slight increment in ultimate load. The high volumetric ratio of steel fibers enabled SIFCON to magnificent tensile properties.


Vestnik MGSU ◽  
2019 ◽  
pp. 22-32
Author(s):  
Farit S. Zamaliev

Introduction. Conducted is to the evaluation of the stress-strain state of the steel-concrete beams with thin-walled section. In recent times, steel-reinforced concrete structures have become widely used in civilian buildings (beams, slabs, columns). Thin-walled section have not found wide application in steel concrete structures, unlike steel structures. Presents the results of numerical studies of beams consisting of concrete, anchors and steel beams. Two investigating of the location of anchors are given. Numerical investigations are presented of steel-concrete beams with thin-walled section based on numerical studies. Testing procedure and test result are given. Results of calculations, comparison of numerical and experimental studies are presented. Materials and methods. For full-scale experiments, steel I-beams with filling of side cavities with concrete were adopted, screws are used as anchor ties, with varied both the lengths and their location (vertically and obliquely). As steel curved C-shaped steel profiles were used steel profiles from the range of the company “Steel Faces”. ANSYS software package was used for computer modeling. A total of 16 steel concrete beams were considered, for which the results of strength and stiffness evaluation were obtained in ANSYS. Results. The data of the stress-strain state of beams on the basis of computer simulation are obtained. The results are used for the production of field samples. Data of computer simulation are compared with the indicators of field experiments. Conclusions. The stress-strain state of steel-concrete structures was studied on the basis of numerical and experimental data. The proposed calculation method gives good convergence with the experimental data. Anchor connections made from self-tapping screws can be used in studies for modeling in steel-concrete beams structures and other anchor devices, ensuring the joint operation of concrete and steel profiles in structures.


2022 ◽  
Vol 1048 ◽  
pp. 333-344
Author(s):  
K. Kumar Arun ◽  
M. Muthukannan ◽  
R. Raja Abinaya ◽  
A. Kumar Suresh

On the demand of reducing the global warming due to cement production which is used as main constituent in the production of concrete and minimizing the environmental impact caused by the waste and its disposal methods, this study was aimed. This study looked in to detail insight view on effective utilization of waste wood ash in the production of geopolymer concrete beams and columns to alternate the conventional reinforced concrete elements in construction industry. Waste wood ash is a waste by product produced in the nearby hotel and factories by burning the waste wood collected from timber industries and the ash are thrown in to land which creates a major environmental pollution. Geopolymer is a novel inorganic eco-friendly binding agent derived from alkaline solution that stimulates aluminosilicate source material (such as metakaolin, fly ash and GGBS). In this research, behaviour of beams in deflection, ductility factor, flexural strength and toughness index and columns in load carrying ability, stress strain behaviour and load-deflection behaviours were examined for three types of concretes (30% WWA – 70% Fly ash Geo-polymer concrete, Fly ash Geo-polymer concrete and Reinforced Cement Concrete). The results showed that inclusion of waste wood ash in geopolymer concrete helped in enhancing the load carrying capacity of beam and column by 42% and 28%. Further, the behaviour of structural elements in stiffness, ductility and toughness were also improved with the replacement of waste wood ash.


2020 ◽  
pp. 002199832097373
Author(s):  
Fares Jnaid

This paper investigates the effects of different parameters on the live load carrying capacity of concrete beams reinforced with FRP bars. The author performed a parametric study utilizing an innovative numerical approach to inspect the effects of multiple variables such as reinforcement ratio, concrete compressive strength, span to depth ratio, FRP type, and bar diameter on load carrying capacity of FRP reinforced concrete beams. This study concluded that unless the span to height ratio is smaller than 8, tension-controlled sections are impractical as they do not meet code requirements for serviceability. In addition, it is recommended to use higher reinforcement ratios when using larger span to depth ratios and/or when using CFRP reinforcing bars. Moreover, larger number of bars with small diameter is more practical than fewer large diameter bars. Furthermore, this research suggests that increasing the concrete compressive strength is associated with a significant increase in the ultimate flexural capacity of FRP reinforced beams.


2018 ◽  
Vol 183 ◽  
pp. 02002 ◽  
Author(s):  
Jacek Selejdak ◽  
Roman Khmil ◽  
Zinoviy Blikharskyy

The article is devoted to an experimental research of the strength of reinforced concrete beams, and its dependence on a simultaneous influence of a corrosion environment and a loading factor. The tests have been carried out upon reinforced concrete specimens of 2100×200×100 mm size, with a regular reinforcement. The beams are of a span equaling to 1,9m with different reinforcing ratio of beams. The acid environment, namely 10 % H2SO4, was taken as a model of an aggressive environment. Reinforced concrete beams have been tested with and without the co-action of the aggressive environment and loading factor. Beams, which underwent a simultaneous action of the corrosive environment and loading, were loaded to a level 0.7 of its load-carrying capacity. The load-carrying capacity in aggressive environment in all the beams of all the series was achieved in 46-60 days. The influence of the simultaneous action of the aggressive environment and loading on the strength of reinforced-concrete beams has been described in the following work. It is necessary to note that the design code of Ukraine does not allow determining load carrying capacity of the beams affected by corrosion with simultaneous influence of loading with adequate accuracy. The analysis of experimental data has been done and the main directions of the design code’s correction have been formulated.


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