The Behavior of a Strengthened Steel Beam Section Under Eccentric Loadings

Thirteen simply supported steel samples have been tested to explain the effects of strengthening steel beams using an external prestressing strand. The samples have the same cross-sectional dimensions and overall length. One steel beam without strengthening was taken as a reference, while the other twelve of them had been strengthening by two external strands at various eccentricity locations and jacking stresses. The strengthening by external prestressing strands is sub-divided into two series according to jacking stress. Each series consists of six steel samples divided according to the eccentricity location of prestressing strand. During tests, it was found that the Load deflection response for the strengthened samples is stiffer as compared with the reference. The increasing percentage in ultimate load capacity was increased to 0.347, 2.758, 3.921, 8.898, 9.326, and 10.256% for beams under jacking stress of 1120 MPa, while increasing percentage in ultimate load capacity were increased to 0.17, 26, 33, 48.5, 13.7, and 69.56% for beams under jacking stress of 815 MPa. On the other hand, the maximum percentages of deflection were decreased to 4.88, 2.44, 20.62, 15, and 9.7% when the jacking stress increase from 815 to 1120 MPa and the ratio of the quarter to mid-span deflection (δ quarter / δ mid) is about 0.528 and 0.497 when jacking stress is 1120 and 815 MPa respectively. So, the increase in jacking stresses from 815 to 1120 MPa will not be preferable because it has a little increasing percentage in stiffening and behaviors compared with other tested beams at the same condition.

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Finite Element Analysis of Cracked One-Way Bubbled Slabs Strengthened By External Prestressed Strands

Journal of Engineering ◽

10.31026/j.eng.2021.01.04 ◽

2021 ◽

Vol 27 (1) ◽

pp. 45-65

Author(s):

Falah Hassan Ibrahim ◽

Ali Hussein Ali

Keyword(s):

Ultimate Load ◽

Load Capacity ◽

The Other ◽

Ultimate Load Capacity ◽

Element Analysis ◽

Line Load ◽

External Prestressing ◽

Service Charge ◽

External Strengthening ◽

Initial Capacity

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, which are L1-E, L2-E, L1-E2, and L2-E2, where the lengths and eccentricities of prestressed wire are (L1=1800, L2=2400, E1=120 and E2=150 mm). The results showed that each reinforcement approach restores the initial capacity of the bubbled slab and improves it in the ultimate load capacity aspect. The minimum and maximum ultimate strength of strengthened cracked bubbled slab increased by (17.3%-64.5%) and (25.7%-76.3%) than solid and bubbled slab, respectively. It is easier to improve behavior with an increased eccentricity of the prestressed wire than to increase its length.

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Finite Element Analysis of Cracked One-Way Bubbled Slabs Strengthened By External Prestressed Strands

Journal of Engineering ◽

10.31026/10.31026/j.eng.2021.01.04 ◽

2021 ◽

Vol 27 (1) ◽

pp. 45-65

Author(s):

Falah Hassan Ibrahim ◽

Ali Hussein Ali

Keyword(s):

Ultimate Load ◽

Load Capacity ◽

The Other ◽

Ultimate Load Capacity ◽

Element Analysis ◽

Line Load ◽

External Prestressing ◽

Service Charge ◽

External Strengthening ◽

Initial Capacity

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Behavior of High Strength Hybrid Reinforcement Concrete Beams

International Journal of Integrated Engineering ◽

10.30880/ijie.2020.12.07.028 ◽

2020 ◽

Vol 12 (7) ◽

Author(s):

Khanda Ali Al-Billbassi ◽

◽

Mushriq Fuad Kadhim Al-Shamaa ◽

Keyword(s):

Residual Strength ◽

Ultimate Load ◽

Steel Fiber ◽

Load Capacity ◽

High Strength ◽

Fiber Reinforced Concrete ◽

Fiber Reinforced ◽

Ultimate Load Capacity ◽

Cross Sectional ◽

Sectional Shape

Six proposed simply supported high strength-steel fiber reinforced concrete (HS-SFRC) beams reinforced with FRP (fiber reinforced polymer) rebars were numerically tested by finite element method using ABAQUS software to investigate their behavior under the flexural failure. The beams were divided into two groups depending on their cross sectional shape. Group A consisted of four trapezoidal beams with dimensions of (height 200 mm, top width 250 mm, and bottom width 125 mm), while group B consisted of two rectangular beams with dimensions of (125 ×200) mm. All specimens have same total length of 1500 mm, and they were also considered to be made of same high strength concrete designed material with 1% volume fraction of steel fiber. Different types and ratios of FRP rebar were used to reinforce these test beams. The study’s principle variables were the amount and type of flexural reinforcement (glass FRP and basalt FRP) and beam cross-sectional shape (rectangular and trapezoidal). The load-deflection behavior and ultimate load capacity of the beams were studied and compared with one another under flexural test with symmetrical two-point loading. The results show that increasing the reinforcement ratio resulted in higher post cracking flexural stiffness, and higher residual strength, as well as caused an increase in the first cracking load and ultimate load capacity ranged from 3 to 16.9%, and 4.6 to 7.3% respectively. When the GFRP rebars replaced by BFRP, the overall beams flexural performance showed outstanding improvements. Moreover the results indicate that increasing the top width of the beam cross section led to a significant enhancement in the first crack load ranged from 16 to 32.4%, also a remarkable increases in the ultimate load capacity in the range of 35.5 to 35.8% were indicated in the trapezoidal beams compared to rectangular beams. However the results show that the deflections were similar and were approximately 1.07–1.54 mm for all test beams. It is worth noting that the general flexural behavior of all the test beams indicated a ductile behavior with a gradual reduction in strength and high residual strength pre to failure due to proposing steel fiber presence.

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The Experimental Study on the Size Effects of Reinforced Concrete Members with Eccentrical Compression

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.166-169.1793 ◽

2012 ◽

Vol 166-169 ◽

pp. 1793-1796

Author(s):

Fan Feng ◽

Jun Zhao ◽

Aizhen Lu

Keyword(s):

Reinforced Concrete ◽

Size Effects ◽

Strain Distribution ◽

Ultimate Load ◽

Load Capacity ◽

Plane Section ◽

Ultimate Load Capacity ◽

Cross Sectional ◽

Concrete Members ◽

Better Than

The size effects of reinforced concrete members with eccentrical compression are experimentally studied, using two sizes of specimens which side lengths of cross-section are 200mm and 400mm, respectively, under the conditions in which e0/h0=0.6. It shows that, with the increase of the size of the specimen, the ultimate load capacity of the specimen decreases, relative to the calculated values; cross-sectional strain distribution of smaller specimens matches plane-section assumption better than larger-sized specimen’s.

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Effect of (B/D) ratio on ultimate load capacity for horizontally curved box steel beam under out of plane concentrated load

Engineering Science and Technology an International Journal ◽

10.1016/j.jestch.2018.09.007 ◽

2019 ◽

Vol 22 (2) ◽

pp. 533-537 ◽

Cited By ~ 1

Author(s):

Bashar Abid Hamza ◽

Ahmed Riyadh Radhi ◽

Qais Al-Madhlom

Keyword(s):

Ultimate Load ◽

Load Capacity ◽

Steel Beam ◽

Ultimate Load Capacity ◽

Concentrated Load ◽

Horizontally Curved ◽

Out Of Plane ◽

Box Steel Beam

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Strengthening of I-Section Steel Beams by Prestressing Strands

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.857.169 ◽

2020 ◽

Vol 857 ◽

pp. 169-176

Author(s):

Kamal Sh. Mahmoud ◽

Mohammed M. Rasheed ◽

Saad Kh. Mohaisen

Keyword(s):

Applied Load ◽

Reference Beam ◽

Experimental Tests ◽

The Other ◽

Steel Beams ◽

Steel Beam ◽

Maximum Deflection ◽

Sectional Area ◽

Simply Supported ◽

Prestressing Strand

Six I-section steel beams had been fabricated and tested to understand the influence of prestressing strand on the load deflection behavior of steel beam. All tested beams are simply supported having the same gross sectional area with clear span (2850) mm, five beams strengthened by two low relaxation seven wire strands, while sixth beam is the reference one. The strengthening beams were subjected jacking stress equal to (1120MPa) and subdivided according to prestressing strand positions (eccentricity). From the experimental tests, it can be noted that, the load deflection curves for strengthened beams are stiffer as compared with reference beam and the percentage of ductility for strengthened beams were decreased when the eccentricity positions change form (0 to 96)mm respectively, on the other hand, the percentage of increasing in maximum applied load for strengthened beams were increased with increasing of strands eccentricity and the maximum applied load reaches to 61.74% as compared with reference, also, the percentage increasing in maximum deflection at middle span for strengthened beams decreases with increasing of strands eccentricity and the minimum percentage of decreasing at middle span of strengthened specimens reaches to 36.31% as compared with the reference beam.

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