scholarly journals Width and Edge Beam Effects on the Ultimate Behaviour of RC Bridge Overhangs

2019 ◽  
Vol 61 (2) ◽  
pp. 131-152
Author(s):  
José Javier Veganzones ◽  
Costin Pacoste ◽  
Raid Karoumi
Keyword(s):  
Bearing Capacity ◽  
Experimental Tests ◽  
Shear Capacity ◽  
Critical Section ◽  
Effective Width ◽  
Ultimate Capacity ◽  
Loading Process ◽  
Arch Effect ◽  
Shear Distribution ◽  
Transition Area

Abstract The bearing capacity of RC overhangs under concentrated loads can be dependent on the width of the slab. The goal of this paper is to investigate the effect of different widths using tests from the literature and non-linear FE-simulations as a reference. Shear force redistributions along the loading process and the shear concrete capacity are analysed. The shear effective width and the influence of an edge beam are also addressed. The results show that the bearing capacity of RC overhangs increase with the width until a transition area is reached and the increase flattens. An increased shear distribution sideways and posterior redistributions under the loading process are enabled. The shear capacity of concrete increases with the width and for loads close to the root an arch effect is observed. The edge beam contributes to a further increase of the ultimate capacity for wide enough overhangs. The effect of the width and the edge beam is not only quantitative but also qualitative since the failure mode and the critical section are influenced. Existing formulation for shear effective widths should be revisited. Experimental tests used for this purpose should consider wide enough specimens to capture the real behaviour of a bridge overhang slab.

scholarly journals Flexure shear capacity of prestressed hollow core slabs

2021 ◽  
Vol 14 (5) ◽  
Author(s):  
Bruna Catoia ◽  
Arthur Lima Rocha ◽  
Marcelo de Araújo Ferreira
Keyword(s):  
Bearing Capacity ◽  
Concrete Strength ◽  
Reduction Factor ◽  
Shear Capacity ◽  
Critical Section ◽  
Experimental Comparison ◽  
Hollow Core ◽  
Shear Cracks ◽  
Prestressing Force ◽  
Additional Reduction

ABSTRACT: Provided that the anchorage capacity is guaranteed at the supports, the bearing capacity of hollow core slabs depends on the shear capacity of the pretensioned concrete webs, wherein the critical section is in a region between h and 2h from the support. For line loads acting within 2h to 6h from the supports, especially for shallow slabs 150 to 200 mm deep, it is likely to have flexure-shear cracks within the transfer region, wherein the bearing capacity is highly affected by the actual prestressing forces at the critical section. Therefore, one of the major questions pondered by structural engineers is to determine the effective amount of prestressing force that affects the shear resistance mechanism near to the support. According to ABNT NBR 14861:2011, the shear capacity is based on the flexure-shear mechanism, wherein the shear strength is a sum of the tensile concrete strength in the slab webs plus the contribution of the prestressing forces at the critical section, wherein a coefficient of 0.15 is considered. However, in both codes NBR 14861 and NBR 6118 it is required that this coefficient 0.15 should be further multiplied by an additional reduction factor in order to take into account the effect of the transmission length near to the support. Considering the current revision of the NBR 14861, this paper presents a theoretical-experimental comparison from standard shear tests of hollow core slabs with nominal depths from 150 to 200 mm carried out in different research at NETPre-UFSCar. Based on the analytical study of each term of the equation for the flexure-shear capacity, it has been observed that the coefficient 0.15 provides a conservative limit for the contribution of the actual prestressing force. Therefore, there is no need to apply any additional reduction factor in order to guarantee a safe design limit for the shear capacity.

Research on Shear Bearing Capacity of Reinforced Concrete Short Beam in Salt-Fog Environment

2012 ◽  
Vol 455-456 ◽  
pp. 1079-1083
Author(s):  
Wei Jun Yang ◽  
Hong Jia Huang ◽  
Wen Yu Jiang ◽  
Yi Bin Peng
Keyword(s):  
Reinforced Concrete ◽  
Bearing Capacity ◽  
Salt Spray ◽  
Test Chamber ◽  
Shear Capacity ◽  
Salt Spray Test ◽  
Concrete Members ◽  
Short Beam ◽  
Shear Bearing Capacity ◽  
Salt Fog

Shantou atmospheric salt-fog environment is simulated with the comprehensive salt spray test chamber. By using reinforced concrete short beams under different water-cement radio, different corrosion time, the inclined section degradation rules of the corrosive reinforced concrete members are researched for establishing shear capacity of short beam formulas in salt-fog environment.

Experimental tests on shear capacity of naturally corroded prestressed beams

2020 ◽  
Vol 21 (5) ◽  
pp. 1777-1793
Author(s):  
Beatrice Belletti ◽  
Jesús Rodríguez ◽  
Carmen Andrade ◽  
Lorenzo Franceschini ◽  
Javier Sánchez Montero ◽  
...  
Keyword(s):  
Experimental Tests ◽  
Shear Capacity ◽  
Prestressed Beams

The Ultimate Shear Bearing Capacity of RC Beam Strengthened with SWR External Prestressing under Dead Load Level when Strengthening

2011 ◽  
Vol 368-373 ◽  
pp. 2175-2179
Author(s):  
Tian Lai Yu ◽  
Hong Kun Han ◽  
Xin Yu Li ◽  
Qiang Ma
Keyword(s):  
Bearing Capacity ◽  
Concrete Beams ◽  
Steel Wire ◽  
Load Level ◽  
Shear Capacity ◽  
Dead Load ◽  
External Prestressing ◽  
Reduction Coefficient ◽  
Shear Bearing Capacity ◽  
The Dead

The shear resistant with SWR (steel wire rope) external prestressing is a kind of new type of reinforcement technique. The advantages of the method are ideal reinforcement effect, durability, and convenient construction. So the method has been paid attention by more and more scientists and technical workers. Through the experiment of 1 basic beam and 3 strengthened beams which are in different dead load levels, the influence of damage degree of original beams and the dead load level of strengthened beams are analyzed. The reduction coefficient values of shear capacity under different dead load level are researched. The research is shown that: with the dead load level increasing, the improve degree of shear capacity of strengthened concrete beams is smaller. The mathematical model is established, which is about dead load level and reduction coefficient of shear capacity of strengthened concrete beams. The result is to take 0.75 as the reduction coefficient of shear capacity. The value is reasonable in calculating the shear bearing capacity of strengthened beams under dead load.

scholarly journals An Experimental Study of Horizontal Bearing Capacity of Vertical Steel Floral Tube Micropiles with Double Grouting

2018 ◽  
Vol 2018 ◽  
pp. 1-11
Author(s):  
Kaiyang Wang ◽  
Yanjun Shang
Keyword(s):  
Bearing Capacity ◽  
Large Scale ◽  
Slip Surface ◽  
Bending Moment ◽  
Shear Capacity ◽  
Soil Reinforcement ◽  
Scale Model ◽  
Soil Pressure ◽  
Floral Tube ◽  
Grouting Pressure

This paper examines the performance of a novel technology, vertical steel floral tube micropiles with double grouting. It is the combination of micropile technology and double grouting technology. A large-scale model tank was applied to impart horizontal bearing capacity, and the slope soil pressure and flexural performance of the micropile were investigated under four experimental conditions. The peak grouting pressure during the double grouting process was defined as the fracturing pressure of the double grouting, and it was positively correlated to the interval time between first grouting and secondary grouting. Compared with traditional grouting, double grouting increased the horizontal bearing capacity of the single micropile with the vertical steel floral tube by 24.42%. The horizontal bearing capacity was also 20.25% higher for the structure with three micropiles, compared with a 3-fold value of horizontal sliding resistance. In the test, the maximum bending moment acting on the pile above the sliding surface was located 2.0–2.5 m away from the pile top, and the largest negative bending moment acting on the pile below the slip surface was located 4.0 m away from the pile top. The ultimate bending moment of the single pile increased by 12.8 kN·m with double grouting, and the bending resistance increased by 96.2%. The experimental results showed that the double grouting technology significantly improved the horizontal bearing capacity of the micropile with the steel floral tube, and the soil reinforcement performance between piles was more pronounced. Also, the shear capacity and the flexural capacity were significantly improved compared with the original technology.

scholarly journals Experimental Study on the Shear Performance of Steel-Truss-Reinforced Concrete Beam-Column Joints

2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
Dafu Cao ◽  
Jiaqi Liu ◽  
Wenjie Ge ◽  
Rui Qian
Keyword(s):  
Bearing Capacity ◽  
Axial Compression ◽  
Compression Ratio ◽  
Shear Failure ◽  
Reinforced Concrete Beam ◽  
Ultimate Bearing Capacity ◽  
Shear Capacity ◽  
Core Area ◽  
Axial Compression Ratio ◽  
Steel Truss

In order to study the influence of the axial compression ratio and steel ratio on the shear-carrying capacity of steel-truss-reinforced beam-column joints, five shear failure interior joint specimens were designed. The effect of different coaxial pressure ratios (0.1, 0.2, and 0.3) and steel contents on the strain, ultimate bearing capacity, seismic performance, and failure pattern of cross-inclined ventral and chord bars in the joint core area was investigated. The experimental results show that the load-displacement hysteretic curves of all test specimens exhibit a bond-slip phenomenon. With the increase of the axial compression ratio, the ultimate bearing capacity of the joint core increases by 3.4% and 5.9%, respectively. While the ductility decreases by 10.3% and 13.1%, and the energy consumption capacity decreases by 3.2% and 5.8%, respectively. The shear capacity and ductility of the member with cross diagonal ventral steel angle in the joint core are increased by 12.9% and 13.4%, respectively. The shear capacity and ductility of the joint can be significantly improved by increasing the amount of steel in the core area. The expression of shear capacity suitable for this type of joint is obtained by fitting analysis, which can be used as a reference for engineering design.

Punching shear behaviour of flat slabs with different reinforcement schemes: openings and rectangularity effects

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Donia Salman ◽  
Rabab Allouzi ◽  
Nasim Shatarat
Keyword(s):  
Structural Engineering ◽  
Experimental Tests ◽  
Shear Capacity ◽  
Punching Shear ◽  
Shear Behaviour ◽  
Cross Sectional ◽  
Content Type ◽  
Flat Slabs ◽  
Reinforced Concrete Slabs ◽  
Rectangular Columns

PurposeThe main goal is to investigate the effect of size and location of opening and column size on the punching shear strength. Openings are often needed in order to install mechanical and electrical services. This process takes away part of the concrete volume which is responsible for resisting the shear forces and any unbalanced moment. Furthermore, the application of rectangular columns in flat slabs is commonly used in practice as they provide lateral stiffness to the building. They are also utilised in garages and multi-storey buildings where these elongated cross-sectional columns reduce the effective span length between adjacent columns.Design/methodology/approachThis research is a numerical-based investigation that is calibrated based on a thirteen previously tested and numerically calibrated slab specimens with no openings. A parametric study is conducted in this study to consider the effect of other parameters, which are the size and location of opening and the rectangularity ratio of column in order to evaluate their effect on the punching shear capacity. A total of 156 models are developed to study these factors. Additionally, the predicted shear carrying capacity of the simulated slabs is calculated using the ACI318–19 and Eurocode (EC2-04) equation.FindingsThe presence of openings reduced the punching shear capacity. The small opening's location and orientation have almost no effect except for one slab. For slabs of large openings, the presence of openings reduced the punching capacity. The punching capacity is higher when the openings are farther from the column. The numerically obtained results of slabs with rectangular columns show lower punching capacity compared to slabs of squared columns with the same length of the punching shear control perimeter. The punching capacity for all slabs is predicted by ACI318–19 and Eurocode (EC2-04) and it is found that Eurocode (EC2-04) provided a closer estimation.Originality/valueThe slabs considered for calibration were reinforced with four different punching shear reinforcement configurations, namely; ordinary closed rectangular stirrups, rectangular spiral stirrups, advanced rectangular spiral stirrups and circular spiral. Generally, there has been limited research on concrete flat slabs with openings in comparison with other subjects related to structural engineering (Guan, 2009) and no research on punching shear with openings of slabs reinforced with these reinforcement schemes. The available research focussed on the effects of openings on the flexural behaviour of reinforced concrete slabs includes Casadei et al. (2003), Banu et al. (2012) and Elsayed et al. (2009). In addition, experimental tests that examined slabs supported on rectangular columns are very limited.

Seismic performance of new adobe bricks masonry: Design and experiment

2021 ◽  
pp. 136943322110463
Author(s):  
Tiegang Zhou ◽  
Xin Wang ◽  
Ben Ma ◽  
Zaiyu Zhang ◽  
Wei Tan
Keyword(s):  
Bearing Capacity ◽  
Seismic Performance ◽  
Rural Areas ◽  
Residential Buildings ◽  
Shear Capacity ◽  
Western China ◽  
Compressed Earth Blocks ◽  
Core Column ◽  
Earth Blocks ◽  
Energy Dissipation Capacity

At present, adobe houses with traditional characteristics are still widely used in rural areas in western China, but their seismic performance is relatively poor, and they often suffer serious damage under earthquake. To improve the seismic performance of traditional adobe buildings while retaining the characteristics of residential buildings, the mechanical properties of compressed earth blocks (CEB) were tested in this study, and the microstructure characteristics of CEB after failure were analyzed by electron microscope. On this basis, six adobe wall specimens were designed and tested by quasi-static loading to investigate the influence of core columns and different types of bricks on its seismic performance. The results show that the core column can improve the bearing capacity and shear capacity of hollow CEB, and it can also significantly increase the bearing capacity, energy dissipation capacity, and ductility of CEB wall. In general, the adobe wall with core columns shows excellent seismic performance, which can provide a new choice for improving the seismic performance of the adobe house.

Experimental Study on the Shear Capacity of Rabbet Cast-in-Place Prefabricated Beam

2020 ◽  
Vol 980 ◽  
pp. 266-274
Author(s):  
Jian Hua Xiao ◽  
Miao Liu ◽  
Jin Li Wang ◽  
Abdulhamid Yakubu Anvah
Keyword(s):  
Mechanical Properties ◽  
Bearing Capacity ◽  
Failure Mode ◽  
Concrete Beam ◽  
Joint Stiffness ◽  
Load Level ◽  
Shear Capacity ◽  
Oblique Section ◽  
Shear Bearing Capacity ◽  
The Relationship

In order to investigate the shear capacity of prefabricated beam, experiments about shear bearing were performed on one integral pouring contrast beam and two prefabrication and assembly beams. Inspecting the relationship between load and deflection under the load, the development regularity of strain between longitude reinforced and stirrup, the shear capacity of cracking load and ultimate bearing capacity, analyzing failure mode of oblique section and connection performance of old and new concrete in the groove, and compared with the mechanical properties of cast-in-place concrete beam. The experimental results indicate that: prefabrication and assembly beam and cast-in-place beams have similar shear bearing capacity and failure mode of oblique section, along with the load level continues to increase, the groove joint stiffness weakened, but has little effect on the overall deformation.

scholarly journals Experimental and Application Study on Underpinning Engineering of Bridge Pile Foundation

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Lei Yan ◽  
Gang Wang ◽  
Min Chen ◽  
Kefeng Yue ◽  
Qingning Li
Keyword(s):  
Bearing Capacity ◽  
Pile Foundation ◽  
Shear Capacity ◽  
Application Study ◽  
Calculation Results ◽  
Shear Bearing Capacity ◽  
Similarity Ratio ◽  
Loading Tests ◽  
New Formula ◽  
Bridge Pile Foundation

In order to study the theory and application of the pile foundation underpinning technology, 3 local node models of underpinning structures with a similarity ratio of 1/1 were made and the progressive repeated static loading tests were conducted. The shear and antislip properties of the joint are studied, and the improved formula for calculating the shear capacity is proposed. The results show that a planting bar plays a major role in shear resistance, and the hoop rate can improve the shear capacity of the interface. The new formula for calculating the shear-bearing capacity is proposed, and the calculation results of the formula of shear-bearing capacity are in good agreement with the experiment results. It is completely feasible to use this formula to calculate the shear-bearing capacity of the pile foundation underpinning structure. During the test, the bearing capacity of the model is good, which proves the reliability of the underpinning technology is good, and it can provide experimental and theoretical basis for the underpinning of similar projects.

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