scholarly journals Calculation of Axial Compression Capacity for Square Columns Strengthened with HPFL and BSP

2016 ◽  
Vol 2016 ◽  
pp. 1-11
Author(s):  
Hua Huang ◽  
Kailin Xi ◽  
Yu Zhang ◽  
Jinghui Shi ◽  
Boquan Liu
Keyword(s):  
Bearing Capacity ◽  
Axial Compression ◽  
High Performance ◽  
Reduction Factor ◽  
Steel Plates ◽  
Strength Reduction Factor ◽  
Compression Performance ◽  
Load Carrying ◽  
Calculation Results ◽  
Primary Damage

The load carrying capacity and failure mechanism of 8 square columns strengthened with high-performance ferrocement laminate (HPFL) and bonded steel plates (BSP) were analyzed on the basis of experiments on the axial compression performance of these columns. Results show that the reinforcing layer worked together with the original columns as a whole, and the load-bearing capacity significantly increased. When failure of the strengthened column occurred, the mortar and concrete were crushed and bulged outward in the middle of the columns, the angle bars and longitudinal steel bars buckled, and some stirrups were pulled out. The chamfering of angle bar momentously affected the primary damage of steel strand. The values of the strength reduction factor and pressure effective utilization coefficient of the mortar were suggested. Based on the experiments and existing tests of 35 columns strengthened with HPFL, equations for the axial compression bearing capacity were proposed and all calculation results agreed well with testing results. Therefore, the calculation method could be used in the capacity design of axial compression strengthened columns.

scholarly journals Experimental Study on Axial Compression Behavior of Masonry Columns’ Strengthening with Bamboo Scrimber Bar Mesh Mortar Layer

2020 ◽  
Vol 2020 ◽  
pp. 1-11 ◽  
Author(s):  
Hongyao Liu ◽  
Min Lei ◽  
Bowang Chen
Keyword(s):  
Experimental Study ◽  
Bearing Capacity ◽  
Axial Compression ◽  
Failure Process ◽  
Engineering Application ◽  
Compression Tests ◽  
Compression Behavior ◽  
Bamboo Scrimber ◽  
Calculation Results ◽  
Strengthening Method

We propose a new method to strengthen structural masonry. To study on the axial compression behavior of masonry columns’ strengthening with a bamboo scrimber bar mesh mortar layer, axial compression tests of twelve masonry columns have been completed: nine strengthened columns and three unstrengthened columns. The failure process, bearing capacity, and failure mode are carried out. The strengthening method of bamboo scrimber bar mesh mortar layer permits the upgrade of the columns’ bearing capacity. The effects of bamboo bar ratio and mortar strengthening ratio on bearing capacity of the reinforced columns are compared. We propose the method for calculating the axial bearing capacity of such a reinforced column. The calculation results agree well with the experimental results, and the research results are available for engineering application.

Characteristic strength of soils underlying foundations considering effect of spatial variability

2020 ◽  
Vol 57 (4) ◽  
pp. 518-536
Author(s):  
Guicai Shi ◽  
Yutao Pan ◽  
Zhaohua Sun ◽  
Yong Liu ◽  
Fook-Hou Lee
Keyword(s):  
Spatial Variability ◽  
Bearing Capacity ◽  
Reduction Factor ◽  
Failure Zone ◽  
Strength Reduction Factor ◽  
Average Strength ◽  
Characteristic Strength ◽  
Random Finite Element ◽  
Weak Zones ◽  
Local Average

In Eurocode EC7, a “characteristic” strength is used as a cautious estimate of the local average strength that governs the bearing capacity of the foundation. The objective of this paper is to examine the correlation between the local average strength and the bearing capacity of a stiff caisson foundation resting on spatially variable ground using random finite element analyses. The results show that using the local average strength over some assumed or postulated failure zones tends to overestimate the mean bearing capacity of the ground. This can be attributed to two possible reasons. Firstly, the postulated failure zone is unlikely to be fully reflective of the real failure zone in spatially variable ground. Secondly, the bearing capacity is more affected by the strength of the weak zones than that of the strong zones. Both of these factors lead to a lowering of the bearing capacity. A more indicative way of determining a characteristic strength that will give a better indication of the bearing capacity is also recommended, together with a strength reduction factor that accounts for the effect of spatial variability.

Experimental Study on Axial Compression Performance of Full-Scale Square Columns of Reinforced Concrete Confined by High-Strength Reinforcement Hoops

2012 ◽  
Vol 446-449 ◽  
pp. 981-988
Author(s):  
Zhen Bao Li ◽  
Wen Jing Wang ◽  
Wei Jing Zhang ◽  
Yun Da Shao ◽  
Bing Zhang ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Yield Strength ◽  
Bearing Capacity ◽  
Axial Compression ◽  
High Strength Steel ◽  
High Strength ◽  
Concrete Columns ◽  
Full Scale ◽  
Compression Performance ◽  
Deformation Ability

Axial compression experiments of four full-scale reinforced concrete columns of two groups were carried out. One group of three columns used high-strength steel with the yield strength of 1000MPa as reinforcement hoops, and the second group used the ordinary-strength steel with yield strength of 400MPa. The axial compressive performances between these two groups were assessed. Compared to the specimen using the ordinary-strength steel, the axial compressive bearing capacity of using the high strength steel dose not increase significantly, while the deformation ability increases greatly. The results also indicate that the stress redistributions of the hoops and the concrete sections are obvious, and long-lasting when specimens achieve the ultimate bearing capacity after the yield of the rebar and local damage of concrete materials, at this time the strain of the specimens developes a lot, especially stress - strain curves of speciments with high-strength hoop all show a wide and flat top.

Analysis of Uniaxial Dynamic Performance of Concrete-Filled Square Steel Tube Composite Column

2011 ◽  
Vol 94-96 ◽  
pp. 220-224 ◽  
Author(s):  
Xi Guang Cui ◽  
Hai Dong Xu
Keyword(s):  
Strain Rate ◽  
Bearing Capacity ◽  
Dynamic Performance ◽  
Concrete Strength ◽  
Steel Tube ◽  
Ultimate Bearing Capacity ◽  
Element Analysis ◽  
Compression Performance ◽  
Calculation Results ◽  
Square Steel Tube

Considering the strain rate then puts forward the modified uniaxial dynamic constitutive model related to strain rate in concrete-filled square steel tube and the modified calculation results match well with the experimental results. Based on the above conclusion, uniaxial compression performance finite element analysis with different strain rate among 10-5/s–10-3/s is completed, the results showed that strain rate can obviously change the dynamic performance of the concrete-filled square steel tube. Through the analysis of the influencing factors of the core concrete compressive strength, it is showed that with the increasing of the strain rate and the improving of concrete strength, the ultimate bearing capacity of concrete-filled square steel tube is higher and the ductility is reduced. With the increasing of stirrup ratio, ultimate bearing capacity is greater and the ductility is enhanced. With the sectional dimensions increasing, the ultimate bearing capacity is greater and the ductility is enhanced.

Bearing Capacity of Concrete Filled Square Steel Tube Short Columns with Inner CFRP Circular Tube under Eccentric Compression

2011 ◽  
Vol 243-249 ◽  
pp. 1272-1278
Author(s):  
Tian Hua Li ◽  
Jun Hai Zhao ◽  
Xue Ying Wei ◽  
Wei Kong ◽  
Xiao Ming Dong
Keyword(s):  
Bearing Capacity ◽  
Circular Tube ◽  
Steel Tube ◽  
Reduction Factor ◽  
Eccentricity Ratio ◽  
Strength Reduction Factor ◽  
The Core ◽  
Short Columns ◽  
Square Steel Tube ◽  
Core Concrete

Based on the unified strength theory, the bearing capacity of the concrete filled square steel tube short columns with inner CFRP circular tube under eccentric compression was analyzed. The restriction effect of the inner CFRP circular tube upon the core concrete, strength reduction factor for eccentricity ratio and the equivalent reduction factor, which considered the ratio of thickness to side effect, were taken into account in the theoretical analysis. The axial bearing capacity formula of the square steel tube short columns filled with inner CFRP circular tube was deduced. By introducing the strength reduction factor for eccentricity ratio, the eccentric bearing capacity formula on the basis of the axial bearing capacity formula was obtained. Parametric studies were carried out to evaluate the effects of intermediate principal stress, different CFRP deployment ratios, eccentricity ratios and the tension-compression ratio on the eccentric bearing capacity of the column. The formula was verified by the comparison of the theoretical results with the experimental data. The results show that inner CFRP circular tube can effectively restrain the core concrete.

Experiment on T-Shaped CFT Stub Columns with Binding Bars Subjected to Axial Compression

2013 ◽  
Vol 838-841 ◽  
pp. 439-443 ◽  
Author(s):  
Zhi Liang Zuo ◽  
Da Xin Liu ◽  
Jian Cai ◽  
Chun Yang ◽  
Qing Jun Chen
Keyword(s):  
Bearing Capacity ◽  
Axial Compression ◽  
Failure Modes ◽  
Local Buckling ◽  
Steel Tube ◽  
Steel Plates ◽  
Buckling Modes ◽  
Cft Column ◽  
Stub Columns ◽  
Strength And Ductility

To improve the mechanical behavior of T-shaped concrete-filled steel tubular (T-CFT) column, the method that setting binding bars along the height of steel tube is proposed. Five T-CFT stub columns with binding bars and another two without binding bars subjected to axial compression were tested. The influences of the spacing and diameter of binding bars on the failure modes, maximum strength, and ductility of T-CFT stub columns are investigated. The experimental results demonstrate that by setting binding bars or decreasing the spacing of binding bars, the buckling modes of the steel plates are changed, the local buckling of the steel plates is postponed, and the confinement effects on the core concrete can be improved significantly. By setting binding bars, the bearing capacity and ductility of the columns are enhanced by 1.17 and 3.38 times at most, respectively. By increasing the diameter of binding bars, the ductility of the columns is improved, but the bearing capacity and buckling strength cannot be improved when the diameter is large enough.

Axial Compression Performance Research of RPC Filled Steel Tube Columns Based on the Unified Strength Theory

2013 ◽  
Vol 351-352 ◽  
pp. 337-341
Author(s):  
Qian Zhu ◽  
Jun Hai Zhao ◽  
Yan Li ◽  
Peng Wu ◽  
Su Wang
Keyword(s):  
Bearing Capacity ◽  
Axial Compression ◽  
Engineering Application ◽  
Steel Tube ◽  
Strength Theory ◽  
Unified Strength Theory ◽  
Bond Slip ◽  
Compression Performance ◽  
Performance Research ◽  
Good Agreement

With consideration of the intermediate principal stress,the calculation formula of bearing capacity of RPC filled steel tube columns under axial compression is deduced based on the twin shear unified strength theory. Combining with the bond-slip theory,new ultimate bearing capacity formula is derived with the highest regard for bond stress. Compared with the theoretical result and the experimental data,good agreement can be found. The results show that unified strength theory and the bond-slip theory are versatile in theoretical analysis of the column. The analysis results can be provided for the optimum design of RPC filled steel tube and the solution has an important practical value for engineering application.

An experimental study of the axial compression performance of two-part precast concrete columns

2021 ◽  
pp. 136943322110159
Author(s):  
Bo Wu ◽  
Zhikai Wei
Keyword(s):  
Bearing Capacity ◽  
Axial Compression ◽  
Axial Load ◽  
Precast Concrete ◽  
Concrete Columns ◽  
Longitudinal Reinforcement ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Compression Performance ◽  
Waste Concrete

Recycled lump concrete (RLC) made with demolished concrete lumps (DCLs) and fresh concrete (FC) provides a solution for effective waste concrete recycling. To promote the development of precast RLC structures, this study tested a new type of connection for precast concrete columns: connecting the upper and the lower halves of columns with bent longitudinal reinforcements and structural adhesive. In this work the behavior of precast RLC columns with the new connection was studied under axial compression. The axial compressive strength of nine two-part columns was tested. The effects of the degree of bending in the longitudinal reinforcement, the replacement ratio of DCLs and the stirrup spacing were investigated. Tests showed that: (1) the failure mode of precast concrete columns is different from that of cast-in-place columns; (2) when the strength of the waste concrete is close to that of the fresh material, there is no significant difference in the axial compression performance of either precast or cast-in-place columns; (3) the bent longitudinal reinforcement causes the axial load bearing capacity of precast concrete columns to be 4.2%–12.3% lower than that of a similar cast-in-place column; (4) reducing the stirrup spacing has little effect on a precast column’s axial load bearing capacity and ductility; (5) when using Chinese and American codes to predict the axial load bearing capacity of the column, the predicted value should be multiplied by a reduction factor.

Discussion on Design Method of Bearing Capacity for Profiled Steel Plate-concrete Composite Floor Slab

2020 ◽  
Vol 5 (1) ◽  
pp. 9-10
Author(s):  
Yumu Liu ◽  
◽  
Li Peng ◽  
Keyword(s):  
Bearing Capacity ◽  
Steel Plate ◽  
Design Method ◽  
Concrete Slab ◽  
Steel Plates ◽  
Floor Slab ◽  
Ordinary Concrete ◽  
Calculation Results ◽  
Steel Composite ◽  
The Common

Profiled steel composite floor slab is widely used for its advantages of convenient construction and flexible design. In this paper, the structural forms and structural requirements of the composite floor slab with profiled steel plates are introduced, then the design and calculation principles are described.Through the comparative analysis of the composite floor slab and ordinary concrete slab calculation, results show that the composite slab of profiled steel plate has more bearing capacity than the common concrete slab of the same specification and can save cost effectively.

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