scholarly journals Experimental Research on Reinforced Concrete Columns Strengthened with Steel Jacket and Concrete Infill

2021 ◽  
Vol 11 (9) ◽  
pp. 4043
Author(s):  
Aleksandar Landović ◽  
Miroslav Bešević
Keyword(s):  
Compressive Strength ◽  
Reinforced Concrete ◽  
Cross Section ◽  
Experimental Research ◽  
Failure Modes ◽  
Steel Tube ◽  
Rc Columns ◽  
Rc Column ◽  
Steel Jacket ◽  
Ductile Behavior

Experimental research on axially compressed columns made from reinforced concrete (RC) and RC columns strengthened with a steel jacket and additional fill concrete is presented in this paper. A premade squared cross-section RC column was placed inside a steel tube, and then the space between the column and the tube was filled with additional concrete. A total of fourteen stub axially compressed columns, including nine strengthened specimens and five plain reinforced concrete specimens, were experimentally tested. The main parameter that was varied in the experiment was the compressive strength of the filler concrete. Three different concrete compression strength classes were used. Test results showed that all three cross-section parts (the core column, the fill, and the steel jacket) worked together in the force-carrying process through all load levels, even if only the basic RC column was loaded. The strengthened columns exhibited pronounced ductile behavior compared to the plain RC columns. The influence of the test parameters on the axial compressive strength was investigated. In addition, the specimen failure modes, strain development, and load vs. deformation relations were registered. The applicability of three different design codes to predict the axial bearing capacity of the strengthened columns was also investigated.

scholarly journals Application of Post-Embedded Piezoceramic Sensors for Force Detection on RC Columns under Seismic Loading

2020 ◽  
Author(s):  
Chien-Kuo Chiu ◽  
Chia-Hsin Wu ◽  
Hsin-Fang Sung ◽  
Wen-I Liao ◽  
Chih-Hsien Lin
Keyword(s):  
Reinforced Concrete ◽  
Failure Modes ◽  
Seismic Loading ◽  
Applied Force ◽  
Seismic Capacity ◽  
Force Detection ◽  
Rc Columns ◽  
Full Size ◽  
Rc Column ◽  
The Relationship

To quantify damage to reinforced concrete (RC) column members after an earthquake, an engineer needs to know the maximum applied force that was generated by the earthquake. Therefore, in this work, piezoceramic transducers are used to detect the applied force on an RC column member under dynamic loading. To investigate the use of post-embedded piezoceramic sensors in detecting the force that is applied to RC columns, eight full-size RC column specimens with various failure modes are tested under specific earthquake loadings. Post-embedded piezoceramic sensors are installed at a range of depths (70-80 mm) beneath the surface of a column specimen to examine the relationship between the signals that are obtained from them and the force applied by the dynamic actuator. The signals that are generated by the post-embedded piezoceramic sensors, which correlate with the applied force, are presented. These results indicate that the post-embedded piezoceramic sensors have great potential as tools for measuring the maximum applied force on an RC column in an earthquake. Restated, signals that are obtained from post-embedded piezoceramic sensors on an RC column in an earthquake can be used to determine the applied force and corresponding damage or residual seismic capacity.

scholarly journals Application of Post-Embedded Piezoceramic Sensors for Force Detection on RC Columns under Seismic Loading

2020 ◽  
Vol 10 (15) ◽  
pp. 5061
Author(s):  
Chien-Kuo Chiu ◽  
Chia-Hsin Wu ◽  
Hsin-Fang Sung ◽  
Wen-I Liao ◽  
Chih-Hsien Lin
Keyword(s):  
Reinforced Concrete ◽  
Failure Modes ◽  
Seismic Loading ◽  
Applied Force ◽  
Seismic Capacity ◽  
Force Detection ◽  
Rc Columns ◽  
Full Size ◽  
Rc Column ◽  
The Relationship

To quantify damage to reinforced concrete (RC) column members after an earthquake, an engineer needs to know the maximum applied force that was generated by the earthquake. Therefore, in this work, piezoceramic transducers were used to detect the applied force on an RC column member under dynamic loading. To investigate the use of post-embedded piezoceramic sensors in detecting the force that is applied to RC columns, eight full-size RC column specimens with various failure modes were tested under specific earthquake loadings. Post-embedded piezoceramic sensors were installed at a range of depths (70–80 mm) beneath the surface of a column specimen to examine the relationship between the signals that were obtained from them and the force applied by the dynamic actuator. The signals that were generated by the post-embedded piezoceramic sensors, which correlate with the applied force, are presented. These results indicate that the post-embedded piezoceramic sensors have great potential as tools for measuring the maximum applied force on an RC column in an earthquake. In other words, signals that are obtained from post-embedded piezoceramic sensors on an RC column in an earthquake can be used to determine the applied force and corresponding damage or residual seismic capacity.

Experimental Research of Bottom Chord Splice Joints with Variable Cross-Section in Steel Roof Truss

2011 ◽  
Vol 105-107 ◽  
pp. 1065-1068
Author(s):  
Hong Xia Wan ◽  
De Xu Yan ◽  
Xiao Ping Wang
Keyword(s):  
Cross Section ◽  
Experimental Research ◽  
Failure Modes ◽  
Variable Cross Section ◽  
Steel Tube ◽  
Engineering Practice ◽  
Variable Cross ◽  
Test Setup ◽  
Roof Truss ◽  
Tension Capacity

A workshop’s roof is designed to use steel tube trusses with the span of 24m. There are three kinds of variable cross-section splice joints of the roof truss bottom chord. Nine splice joint specimens, three for each kind, were tested to obtain their tension capacity and failure modes. A special test setup is designed to introduce the tension load to the splice joint specimen. The paper detailed introduced the test setup and method, discussed the failure load and failure mode of the joints. Experimental research indicated that the bottom chord splice joint with variable cross-section of the roof is safe, reliable, having high bearing capacity. The research also validated the correctness of the design and calculation, and provided the basis for the application of such joints in the engineering practice.

Seismic assessment of reinforced concrete columns with short lap splices

2021 ◽  
pp. 875529302199483
Author(s):  
Eyitayo A Opabola ◽  
Kenneth J Elwood
Keyword(s):  
Reinforced Concrete ◽  
Failure Mode ◽  
Failure Modes ◽  
Concrete Columns ◽  
Seismic Assessment ◽  
Rc Columns ◽  
Lap Splices ◽  
Displacement Response ◽  
Force Displacement ◽  
Probable Failure

Existing reinforced concrete (RC) columns with short splices in older-type frame structures are prone to either a shear or bond mechanism. Experimental results have shown that the force–displacement response of columns exhibiting these failure modes are different from flexure-critical columns and typically have lower deformation capacity. This article presents a failure mode-based approach for seismic assessment of RC columns with short splices. In this approach, first, the probable failure mode of the component is evaluated. Subsequently, based on the failure mode, the force–displacement response of the component can be predicted. In this article, recommendations are proposed for evaluating the probable failure mode, elastic rotation, drift at lateral failure, and drift at axial failure for columns with short splices experiencing shear, flexure, or bond failures.

scholarly journals Study on Retrofitting of RC Column Using Ferrocement Full and Strip Wrapping

2019 ◽  
Vol 5 (11) ◽  
pp. 2472-2485
Author(s):  
Balamuralikrishnan R. ◽  
M. Al Madhani ◽  
R. Al Madhani
Keyword(s):  
Numerical Simulation ◽  
Cross Section ◽  
Volume Fraction ◽  
Single Layer ◽  
Longitudinal Reinforcement ◽  
Element Analysis ◽  
Rc Columns ◽  
Rc Column ◽  
Concrete Form ◽  
Wrapping Technique

Ferrocement is one of the cement-based composites used for retrofitting and rehabilitation among many applications. Ferrocement is one of the reinforced concrete form with lightweight and thin composite with durability and environmental resistant that strengthen the conventional RC columns to increase its strength and serviceability. This paper examines the performance of the ferrocement wrapping in RC columns experimentally with numerical simulation using ANSYS19. Totally sixteen number of RC column of size 150 mm × 150 mm in cross section and 450 mm in length were cast and tested in laboratory. Twelve are retrofitted columns with respect to volume fraction and wrapping technique. Six columns were retrofitted by full wrapping technique and six columns of strip wrapping technique. The remaining four columns are control columns in virgin condition to compare with the retrofitted columns. Concerning the volume fraction of each specimen, the number of pre-woven mesh layers were single layer, double layer and three layers. C30 concrete grade adopted in all specimens as per ACI Committee 211-1.91 with 4H8 longitudinal reinforcement and H6 of 75mm c/c ties. As the previous researchers examined the ferrocement and proved its efficiency. This study aims to examine the ferrocement in full and strip wrapping technique to compare their efficiency to increase the strength. Finite element analysis using ANSYS19 adopted to compare the experimental data with the numerical simulation. The results are analyzed and observed that the ferrocement has increased the confinement and strength of the RC columns. 

Punching in two-way RC flat slabs with openings and L section columns

2019 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Valdemir Colares Pinto ◽  
Vitor Branco ◽  
Denio Ramam Oliveira
Keyword(s):  
Reinforced Concrete ◽  
Cross Section ◽  
Failure Modes ◽  
Computational Simulation ◽  
Experimental Results ◽  
Design Codes ◽  
Nonlinear Simulation ◽  
Content Type ◽  
Flat Slabs ◽  
Failure Loads

Purpose This study aims to contribute to a better understanding of the influence of the position of openings around L cross-section columns in reinforced concrete flat slabs through a nonlinear computational analysis compared to experimental results. Design/methodology/approach Tests on four reinforced concrete flat slabs of 1800 x 1800 x 120 mm3 were carried out under symmetrical punching; one slab was referenced (without hole) and three had square holes of 100 x 100 mm2 close to columns and with centroid on the critical perimeter at 0.5 d and 2.0 d of the loaded area. A nonlinear analysis of the slabs was performed to aid the interpretation and preview of the experimental results, and to estimate the ultimate loads and failure modes. These estimates followed recommendations of ACI 318, Eurocode 2, NBR 6118, MC 2010 and critical shear crack theory. Findings The results showed that the presence of holes in the analyzed regions does not influence significantly the behavior of the slabs, leading to conservative structural design once the ultimate load estimates are low, while the computational results adequately estimated the slabs’ behavior. Research limitations/implications A few limitations were observed on how to implement the correct modeling system for computational nonlinear simulation. Practical implications All design codes underestimated failure loads and the theoretical method was not much better. The nonlinear computational simulations were satisfactory, presenting results close to experimental ones (97 per cent accuracy). Computational simulation also showed that the presence of holes does not significantly influence the load-vertical displacement behavior or failure loads. Social implications Structural and civil engineers and designers can observe with better details the punching phenomenon and make take secure decisions to building projects. They can preview accurate cases that are not cited in design codes and literature. Originality/value This is a very rare subject in literature that interests the entire scientific community and especially reinforced concrete designers. Presenting a new methodology to nonlinear flat slab with openings modeling to punching shear provoked by L cross section columns, case that is not cited in literature and design codes.

Anchorage Capacity of Headed Bars in Steel Fiber Reinforced Concrete

2021 ◽  
Author(s):  
Payal Sachdeva ◽  
A.B. Danie Roy ◽  
Naveen Kwatra
Keyword(s):  
Compressive Strength ◽  
Reinforced Concrete ◽  
Failure Modes ◽  
Steel Fiber ◽  
Fiber Reinforced Concrete ◽  
Steel Fibers ◽  
Fiber Reinforced ◽  
Steel Fiber Reinforced Concrete ◽  
Concrete Compressive Strength ◽  
Pull Out

Headed bars (HB) with different head shapes (Square, Circular, and Rectangular) and bar diameters (db: 16, 20, and 25 mm) embedded in steel fiber reinforced concrete have been subjected to pull-out test. The influence of head shapes, concrete compressive strength (M20 and M40), db, and steel fibers (0, 0.5, 1, and 1.5%) on the anchorage capacity of HB have been evaluated. Numerical model for improving the anchorage capacity of HB has also been proposed. Results have revealed that the anchorage capacity of HB increases with the increase in concrete compressive strength, db, and steel fibers, which have been validated by non-linear regression analysis using dummy variables. Two failure modes namely, steel and concrete-blowout have been observed and the prevailing mode of failure is steel failure. Based on load-deflection curves and derived descriptive equations, it is observed that the circular HB has displayed the highest peak load.

Performance of the Casing-Plug Joints of Square Steel Tube Structures

2011 ◽  
Vol 462-463 ◽  
pp. 265-270
Author(s):  
Xiu Gen Jiang ◽  
Ning Xu ◽  
Xu Dong Shi ◽  
Yu Huan Wu ◽  
Xing Hua Chen ◽  
...  
Keyword(s):  
Cross Section ◽  
Carrying Capacity ◽  
Failure Modes ◽  
Influence Factors ◽  
Steel Tube ◽  
Load Carrying Capacity ◽  
Ansys Software ◽  
Tube Cross Section ◽  
Load Carrying ◽  
Square Steel Tube

The performance of the casing-plug joint, including load carrying capacity, stiffness, failure modes, and its influence factors of the casing tubes set inside and outside of the main tubes are analyzed by simulating square steel tube casing-plug joints structures with ANSYS software in this paper. The formulas of the optimum l/L for the joints with the size of the main tube cross-section 200mm× 200mm are given in this paper.

Experimental Study on Behaviour of RC Column Confined by CFRP and Steel Fibre

2012 ◽  
Vol 446-449 ◽  
pp. 3146-3149 ◽  
Author(s):  
Xiao Xia Li
Keyword(s):  
Experimental Study ◽  
Reinforced Concrete ◽  
Steel Fibre ◽  
Rc Columns ◽  
Steel Fibres ◽  
Rc Column ◽  
The Third

12 RC columns specimens are divided 4 groups which have different eccentricities. Each group has 4 specimens, The first specimen was just made of reinforced concrete. The second was wrapped with 3 lays CFRP. The third had steel fibres added to it. The last was reinforced with steel fibres and wrapped with CFRP.The results showed that the introduction of fibres as well as wrapping the specimens with FRP improve the strength of concrete,especially its ductility.

Experimental Study on Compressive Bearing Capacity of High Strength Concrete-Filled Steel Tube Composite Columns

2011 ◽  
Vol 368-373 ◽  
pp. 410-414 ◽  
Author(s):  
Hong Zhen Kang ◽  
Lei Yao ◽  
Xi Min Song ◽  
Ying Hua Ye
Keyword(s):  
Compressive Strength ◽  
Reinforced Concrete ◽  
High Strength Concrete ◽  
High Strength ◽  
Steel Tube ◽  
Test Results ◽  
Concrete Filled Steel Tube ◽  
Composite Columns ◽  
Strength Concrete ◽  
Axial Compressive Strength

To study axial compressive strength of high strength concrete-filled steel tube composite columns, tests of 18 specimens were carried out. Parameters of the specimens were the confinement index of concrete-filled steel tube, the cubic strength and the stirrup characteristic value of concrete outer of steel tube. Test results show that the concrete-filled steel tube and the reinforced concrete deformed simultaneously in the axial direction before and at the peak value of axial compressive force; after failure of the reinforced concrete, the concrete-filled steel tube can still bear the axial load and deformation; the main influential factors of axial compressive capacity are confinement index, the cubic strength and the stirrup characteristic value of concrete outer of steel tube. The accuracy of the formula of axial compressive strength of composite columns provided by CECS 188:2005 is proved by the test results of this paper.

Sign in / Sign up

Export Citation Format

Share Document