scholarly journals Carbon Fiber Strengthening of Geopolymer Concrete Wall Panels with Iron Fillings

2018 ◽  
Vol 7 (4.20) ◽  
pp. 399
Author(s):  
Dr. Wissam K. Al-Saraj ◽  
Dr. Layth Abdulbari Al-Jaberi ◽  
Sahar J. AL-Serai ◽  
. .
Keyword(s):  
Carbon Fiber ◽  
Bearing Capacity ◽  
Ultimate Bearing Capacity ◽  
Alkaline Solutions ◽  
Strengthening Effect ◽  
Concrete Wall ◽  
Load Bearing ◽  
Lateral Deflection ◽  
Wall Panels ◽  
Reinforced Concrete Wall

Wall is a vertical plate member resisting vertical (in-plane) or lateral loads. Load-Bearing walls were referred to RC wall panels which were commonly used as load-bearing structural members, braced and laterally supported by the rest of the structure, local materials such as Metakaolin and alkaline solutions are used to cast (600x400) mm reinforced concrete wall panels with 40 mm thickness. To find the ultimate bearing capacity and lateral deflection of wall panels. Seven specimens are divided  in two groups to study the variation effect of iron filling (0, 0.5, 0.75 and  1.0)%   and carbon fiber (225, 125 and 90 )mm spacing center to center of strips.  The result shows that the maximum increasing are 17% and 14% for ultimate bearing capacity and cracking load of wall panels respectively, when iron filling is 1%. Also, the using of carbon fiber with 90 mm spacing center to center of strips leds to increasing in ultimate bearing capacity and cracking load by 31% and 7% respectively. Lateral deflection of wall panels was measured and compared with the reference wall to investigate the strengthening effect. 

Carbon Fiber Strips Retrofitting System for Precast Reinforced Concrete Wall Panel

2015 ◽  
Vol 660 ◽  
pp. 208-212 ◽  
Author(s):  
Mihai Fofiu ◽  
Andrei Bindean ◽  
Valeriu Stoian
Keyword(s):  
Reinforced Concrete ◽  
Carbon Fiber ◽  
Bearing Capacity ◽  
Maximum Load ◽  
Fiber Reinforced Polymers ◽  
Wall Panel ◽  
Concrete Wall ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Reinforced Concrete Wall

This paper presents the retrofitting procedure used on a precast reinforced concrete wall panel (PRCWP) in order to restore its initial load bearing capacity. The specimen used in this experimental test is one from the residential multistoried buildings constructed in Romania from the 1970 onwards. All of the characteristics of the element are from the specific era, only scaled down with a factor of 1:1,2. The element was subjected to in-plane reversed cyclic loading to simulate its seismic behavior and obtain its maximum load bearing capacity. After the test we retrofitted the element using Carbon Fiber Strips Externally Bonded (EBR) and anchored with Carbon Fiber Reinforced Polymers (CFRP) mesh. The porpoise of the paper is to compare the maximum loading bearing capacity of the unstrengthen and strengthen elements in order to compare them and examine the efficiency of this retrofitting procedure.

scholarly journals Axial Behaviour of Slender RC Circular Columns Strengthened with Circular CFST Jackets

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Yiyan Lu ◽  
Tao Zhu ◽  
Shan Li ◽  
Weijie Li ◽  
Na Li
Keyword(s):  
Bearing Capacity ◽  
Ductile Failure ◽  
Steel Tube ◽  
Experimental Results ◽  
Strengthening Effect ◽  
Load Bearing Capacity ◽  
Rc Columns ◽  
Load Bearing ◽  
Cfst Columns ◽  
Material Utilization

This paper investigates the axial behavior of slender reinforced concrete (RC) columns strengthened with concrete filled steel tube (CFST) jacketing technique. It is realized by pouring self-compacting concrete (SCC) into the gap between inner original slender RC columns and outer steel tubes. Nine specimens were prepared and tested to failure under axial compression: a control specimen without strengthening and eight specimens with heights ranging between 1240 and 2140 mm strengthened with CFST jacketing. Experimental variables included four different length-to-diameter (L/D) ratios, three different diameter-to-thickness (D/t) ratios, and three different SCC strengths. The experimental results showed that the outer steel tube provided confinement to the SCC and original slender RC columns and thus effectively improved the behavior of slender RC columns. The failure mode of slender RC columns was changed from brittle failure (concrete peel-off) into ductile failure (global bending) after strengthening. And, the load-bearing capacity, material utilization, and ductility of slender RC columns were significantly enhanced. The strengthening effect of CFST jacketing decreased with the increase of L/D ratio and D/t ratio but showed little variation with higher SCC strength. An existing expression of load-bearing capacity for traditional CFST columns was extended to propose a formula for the load-bearing capacity of CFST jacketed columns, and the predictions showed good agreement with the experimental results.

Stress of Carbon Fiber Reinforced Polymer Tendons in Prestressed Simply Supported Beams

2013 ◽  
Vol 689 ◽  
pp. 353-357
Author(s):  
Chong Xi Bai ◽  
Xin Yan Shao ◽  
Qiu Ping Wang
Keyword(s):  
Carbon Fiber ◽  
Bearing Capacity ◽  
Fiber Reinforced Polymer ◽  
Carbon Fiber Reinforced Polymer ◽  
Fiber Reinforced ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Simply Supported ◽  
Reinforced Polymer ◽  
Carbon Fiber Reinforced

The law of stress increment of unbonded carbon fiber reinforced polymer (CFRP) tendons at service stage and flexural load bearing capacity limit state is unclear, so it is difficult to accurately calculate crack width, deflection and load bearing capacity. In order to calculate the stress of CFRP tendons, deformation compatibility condition and moment-curvature analysis method are used to compile nonlinear full-range analysis programs of simply supported concrete beam partially prestressed with unbonded CFRP tendons. The computing results of stress in CFRP tendons are in good agreement with the tested results as a whole, so it indicates that the simulation analysis programs are reliable.

The assessment of the level of local strengthening of pipe steel welded connections

2020 ◽  
Vol 10 (3) ◽  
pp. 252-262
Author(s):  
Marat Z. Yamilev ◽  
◽  
Egor А. Tigulev ◽  
Andrey А. Raspopov ◽  
◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Numerical Model ◽  
Bearing Capacity ◽  
Pipe Steel ◽  
Carbon Steels ◽  
Strengthening Effect ◽  
Low Carbon ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Welded Connection

The metal welding is accompanied by the formation of mechanically non-homogenous sections of welded connection. The pipeline welded connections also have sections, which are different in structure, chemical composition and mechanical properties. The mechanical inhomogeneity affects the load bearing capacity of welded connection and the structure as a whole, which is necessary to take into consideration when performing calculation analysis. So far, the specialists have established the dependencies in assessment of welded connection strength with various types of heterogeneous sections. However, this phenomenon has received little attention in case of pipeline welded connections made of low carbon steels. The existing theoretical models do not reflect actual anisotropy of mechanical properties of the welded connections and weld adjacent zone. The present study considers the model of welded connections of K56 pipe steels with various strength characteristics of sections of welded seam and weld adjacent zone, without defects. The assessment of mechanical inhomogeneity influence on load bearing capacity of welded connections was performed by applying the finite-element modelling of its stress-strain state. The developed numerical model helps to determine and optimize the criteria of testing of full scale samples of pipe steel welded connections with regards to the implementation of local strengthening effect. The research results demonstrated that the degree of contact strengthening in welded connections with X-shape grooving is higher than in welded connections with V-shaped grooving by 8 % at similar relative thickness of soft interlayer. The suggested numerical model can be applied for detailed calculations of pipelines with regards to the mechanical inhomogeneity of its welded connections.

scholarly journals CRACKING AND BEARING CAPACITY OF REPAIRED REINFORCED CONCRETE WALL-FLOOR JOINTS/SUREMONTUOTŲ MONOLITINIŲ SIENŲ IR PERDANGŲ SANDŪRŲ PLEIŠĖJIMAS IR LAIKOMOJI GALLA

1997 ◽  
Vol 3 (11) ◽  
pp. 24-29
Author(s):  
Algirdas Kudzys
Keyword(s):  
Reinforced Concrete ◽  
Bearing Capacity ◽  
Concrete Wall ◽  
Reinforced Concrete Wall

Nagrinėjamos supleišėjusių ar kitaip pažeistų pastatų laikančių jų konstrukcijų bei jų sandūrų atstatymo ir remonto problemos. Jos ypač svarbios dėi tos priežasties, kad realaus pastato suremontuotų konstrukcijų laikomosios galios įvertinimas yra labai sudėtingas. Neardančiais bandymais pakankamai tiksliai galima nustatyti medžiagų fizinesmechanines savybes, tačiau konstrukcijos stiprumo įvertinimas negali būti patikimas, neatlikus laboratorinių eksperimentų su natūralaus dydžio modeliais. Eksperimentinių tyrimų metu buvo išbandyti daugiaaukščių gyvenamųjų namų gelžbetoninių monolitinių sienų ir kompleksinių perdangų (surenkama 60 mm storio gelžbetoninė plokštė monolitinama iš 76 mm diametro plastmasinių vamzdžių suformuojant tuštumas ir betonuojant kartu su sienų elementais) sandūrų modeliai (1 pav.). Pleišėtumo, irimo pobūdžio ir stiprumo analizei buvo naudojami natūralaus dydžio šeši pastato vidinių sienų ir perdangų sandūrų mazgai bei du išorinių sienų ir perdangos bandiniai (2 pav.). Pagrindiniai kintamieji eksperimentų metu buvo sienų ir perdangų armatūros kiekis bei vertikaliosios apkrovos dydis (1 lentelė). Suremontavus sandūrų bandinius (injektavus po spaudimu epoksidinę dervą į pažeistas konstrukcijų zonas) po anksčiau atliktų laikomosios galios nustatymo eksperimentinių tyrimų, jie buvo pakartotinai paveikti kintamosiomis vertikaliosiomis ir horizontaliosiomis apkrovomis. Apkrovimui buvo panaudota speciali įranga su apkrovos pulsatoriais laikantis apkrovimo eiliškumo, koks buvo taikytas bandant naujus bandinius (3 pav.). Horizontalioji apkrova buvo perduodama per reversing pulsatorių kontroliuojant poslinkio R dydį (4 pav.). Bandinių irimo pobūdis, pleišėtumas bei stiprumas buvo palyginti su naujų mazgų bandymo rezultatais (5 pav., 2 lentelė).

Bamboo reinforced concrete wall panels under one way in-plane action

2018 ◽  
Vol 22 (2) ◽  
pp. 1475-1488 ◽  
Author(s):  
N. Ganesan ◽  
P. V. Indira ◽  
P. R. Himasree
Keyword(s):  
Reinforced Concrete ◽  
Concrete Wall ◽  
Wall Panels ◽  
Reinforced Concrete Wall
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