It is well known that the success of this procedure is dependent on the monolithic behavior of the composite element. Repairing and strengthening of damaged rc columns using thin. Textilereinforced mortar trm versus frp jacketing for. The retrofitting of reinforced concrete columns catalin. Research article materials and jacketing technique for. Pdf steel jacketing for improvement of column strength. Structural rehabilitation of columns with reinforced concrete jacketing e s ju. Apr 07, 2018 strengthening column using micro concrete jacketing remove entire plaster to reach parent concrete surface if the column is plaster. Jacketing and collars for concrete column beam strengthening jacketing and collars for strengthening of concrete structures jacketing is the process whereby a section of an existing structural member is restored to original dimensions or increased in size by encasement using suitable materials. Methods of strengthening of foundations in buildings. Common methods for strengthening columns include concrete jacketing.
The selfcompaction behavior of the fibrous uhpscc is very effective in terms of casting the rc column jackets. Place and fixed around the column keeping in mind the required thickness of the jacketing. His research interests widely cover mechanics of reinforced concrete structures. Group 1 consisted of 18 column cores jacketed by normal strength concrete with a maximum aggregate size of 4. Structural rehabilitation of columns with reinforced. This paper introduces a new steel jacketing method for reinforced concrete rc columns with lap splice and evaluates its performance by a series of axial tests of concrete cylinders. Experimental and analytical work is reported for jacketed concrete columns, including short lap splices at the base. Three largescale columns were tested under cyclic loading. Jacketing is the most popularly used method for strengthening of building columns. Four full scale beams were first loaded to certain levels of ultimate capacity 0, 60%, 77%, 100% of failure load. Seismic steel jacketing of rectangular rc bridge columns for the mitigation of lap. Read about company and get contact details and address.
Concrete jacketing is a commonly used method to strengthen existing steel columns. Mechanical performance and applications ahmed elbadawy sayed, assoc. Seismic retrofitting of cruciformshaped columns by. The columns of bridge i1556 located in sparks, nevada, were used in the study.
Pdf strengthening of reinforced concrete columns by steel. Nov 06, 2017 jacketing of concrete columns slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising. Single component readymade micro concrete masteremaco 346 of basf in 25 kg bag to emptied in a small drum. Jacketing consists of added concrete with longitudinal and transverse reinforcement around the existing column.
Analysis and retrofit of fixed flared columns with glass. Tests on column specimens retrofitted with jacketing of fiberreinforced polymer frp resulted in improved performance compared with that obtained for the asbuilt column specimens. Behavior of reinforced concrete columns strenghtened by. Rc columns using the fibrous uhpscc as a jacketing material, as it is a high compressive strength material and reinforced by ffp fibers, which resulted in enhancing the ductility and reducing the jacketing thickness. Seismic steel jacketing of rectangular rc bridge columns. It improves axial and shear strength of column and major strengthening of foundation may be avoided. Strengthening and repair of reinforced concrete columns. This is the typical case of edge or corner columns in buildings. Extensive investigations on seismic retrofitting of reinforced concrete columns have been undertaken in recent years and many retrofitting methods have been developed and reported in the literature. Jacketing of preloaded steel columns sciencedirect. Deflections along the column length as well as crack development were also monitored. The variables in the test specimens include the amount of column transverse reinforcement and jacketing of the column. Rc columns externally strengthened with rc jackets ciasitalia.
Prefabricated composite jacketing of rc columns for enhanced. Aci structural journal technical paper following previous studies, the authors describe an experimental study performed to analyze the influence of the interface treatment on the seismic behavior of columns strengthened by reinforced concrete rc jacketing to increase their ultimate bending moment. A design expression, specifically developed to address the hybrid frp jacketing, and calibrated based on the study undertaken, is also presented. Concrete jacketing can be made in two different manners.
The jackets consist of multilayer prefabricated glass fiber reinforced composite shells adhered together. Jacketing of beam onesided jackets or 3 and 4 sided jackets. Lastly, the costbenefit analysis is conducted and major conclusions are drawn. Pdf reinforced concrete jacketing interface influence on. Retrofitting of existing rcc buildings by method of jacketing mlmce 1 civil engineering. Structural rehabilitation of columns with reinforced concrete jacketing esju. Strengthening of concrete columns using hybrid frp jacketing. Waghmare address for correspondence acharya shrimannarayan polytechnic,piprim, wardha maharashtra abstract seismic protection of buildings is a needbased concept aimed to improve the performance of any structure under future earthquakes. Jacketing of concrete columns slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising. Saatcioglu and ozcebe 1989 pointed out that a crosstie with 90.
Jacketing of existing columns with strengthening of columns and beams. Prefabricated composite jacketing of rc columns for. Despite the wide application of concrete jacketing in strengthening the steel columns of existing structures, research on the jacketing of such columns whilst under load is still in the early stages. Strengthened columns, concrete jacketing, core concrete quality. Fundamental principles that govern retrofitting of.
Considering bridge 1 and 2 which have circular columns and. As in the case of rc structure, columns are subjected to uniform and continuous loading which increases with the increase in. View jacketing of column ppts online, safely and virusfree. An experiment was performed by chai and priestley to investigate the retrofit of circular columns with steel jacketing.
The vertical elements needs enhanced load carrying capacity when one or few of the following are true. This research investigates the behavior of rc columns strengthened using steel jacket technique. Strengthening of footing by jacketing if the bearing area of footing has to be increased without strengthening of the column, soil pressure on the extended foundation area has to. Ferrocement jacketing for restrengthening of square reinforced. Structural rehabilitation of columns with reinforced concrete. The use of fiberreinforced polymers frp has gained considerable popularity among all jacketing techniques, due to the favorable properties offered by these materials, namely. The effectiveness of prefabricated composite jacketing to retrofit existing circular reinforced concrete rc bridge columns for enhanced seismic shear strength is described in this paper. In this experiment, for circular columns, two half. It is well known that the success of this procedure is dependent on. Seismic retrofit of rc circular columns using prefabricated. Pdf repairing and strengthening of damaged rc columns using. Both of these deficiencies were addressed by using a glass fiberepoxy jacket. Reinforced concrete rc columns often require consolidation or rehabilitation to enhance their capacity to endure the loads applied. Ranson civil technologies private limited offering rcc column jacketing and repairs, sizearea.
Strengthening and repair of reinforced concrete columns by. Deterioration in the capacity of reinforced concrete rc infrastructure e. Received april 27, 2009 accepted may 5, 2009 concrete jacketing is a commonly used method to retrofit or strengthen. Behavior of reinforced concrete columns strengthened by steel jacket. Pdf steel jacketing for improvement of column strength and. Strengthening column using micro concrete jacketing.
This paper investigated the use of external steel jacketing for seismic retrofit of non. This resulted in implementation of steel and composite jacketing of the columns, and of installing and upgrading of the restraining devices at expansion joints for many bridges for which the seismic retrofit was deemed necessary. Bournas, dionysios, thanasis triantafillou, and stijn matthys. Three months later, the columns were strengthened by rc jacketing after their surface had been prepared considering. The experimental program included casting of nine reference 300 mm long reinforced concrete column specimens. Pdf strengthening of reinforced concrete columns by. Rc jacketing, leads to a uniformly distributed increase in strength and stiffness of columns, does not require specialized workmanship, disadvantage increase in dead weight. Strengthening and rehabilitation by reinforced concrete jacketing of columns is assessed, considering different practical aspects. The northridge earthquake inflicted various levels of damage upon a large number of caltrans bridges not retrofitted by column jacketing. May 17, 2017 the vertical elements needs enhanced load carrying capacity when one or few of the following are true.
For this purpose, a threedimensional model of finite element fe is devised mainly to investigate and analyze the effect of. The upgrading of existing reinforced concrete rc structures through jacketing of columns has become a very popular technique in a increasingly large number of rehabilitation projects, both seismic and nonseismic. The additional crosssection area helps the column transfer more load while providing additional confinement. Sustainability necessitates the protection of infrastructure from any kind of deterioration over the life cycle of the asset. This paper aims at studying the conduct and capacity of rc square columns, those reinforced with steel jacketing under static preloads. Pdf retrofitting of existing rcc buildings by method of. Faculty of engineering, al azhar university nasr city, cairo, egypt abstract in the present study, the steel jacketing technique with variable vertical angles size. Steel jacketing technique used in strengthening reinforced concrete rectangular columns under eccentricity for practical design applications ezzeldeen, h. At first, 45 concrete cylinders were fabricated with varying design compressive strengths of 21, 27 and 35 mpa and.
Proceedings of the 9th international symposium of the fiberreinforced polymer reinforcement for reinforced concrete structures frprcs9. Although hundreds of thousands of successful concrete and masonry buildings are annually constructed worldwide, there are large numbers of concrete and masonry structures that deteriorate, or become unsafe due to changes in loading, changes in use. Research article materials and jacketing technique. Jacketing is one of the most frequently used techniques to strengthen reinforced concrete rc columns. Textilereinforced mortar trm versus frp jacketing for seismic retrofitting of old type rc columns with lapspliced or continuous bars. Seismic steel jacketing of rectangular rc bridge columns for. Pdf reinforced concrete rc jacketing is most frequently used to strengthen columns. Repairing and strengthening of damaged rc columns using. Steel jacketing for concrete column structural engineering. From the middle of the last century, concrete jackets have been provided primarily to serve as protection against corrosion and fire 1, and. Generally, steel jacketing is consisting of steel angle profile, steel platesstrips with different. If you continue browsing the site, you agree to the use of cookies on this website. The bonding and jacketing construction method is classified as a method that involves increasing the number of retrofitting members and includes the 6 steel plate bonding method 7 fiberreinforced plastic bonding method and 8 steel plate jacketing construction method, as well as the fiberreinforced plastic jacketing.
Download fulltext pdf strengthening of reinforced concrete columns by steel jacketing. Pdf retrofitting of reinforced concrete column by steel. However contradictory results and conclusions are not rare especially for jacketing of rectilinear columns, and there is not a clear picture on the. A practical approach for the strength evaluation of rc. Additional floors are to be added to the building 3. It is used to increase loadcarrying capacity and ductility of weak existing members by means of a simple and cheap method. The following photos 1 4 illustrate the practical way of jacketing a footing by reinforced concrete. Disadvantages increase in the concrete member size obtained after the jacket the need to construct a new. This study focuses on the improvement of square jacketing technique in effective restrengthening of existing rc building column. This research aims to investigate the efficiency of repairing damaged concrete columns using thin concrete jacketing. Fragility curves of concrete bridges retrofitted by column. Now by tapping with a light hammer, identify of loose concrete portions are present. Development of fragility curves of bridges retrofitted by. The frp jacket needed to be anchored in the reentrant corners of.
The concrete has achieved less strength than the design mix 2. Then, after formation of cracks or failure, they were repaired by reinforced concrete jacketing method and tested again up to failure. With this method, axial strength, bending strength, and stiffness of the original column are increased. In this respect, this study represents results of fragility curve development for two 2 sample bridges typical in southern california, strengthened for seismic retrofit by means of steel jacketing of bridge columns. All columns tested by these researchers presented good results with increases in column ultimate capacity ranging from two to close to four times the resistance of the column without jacketing. Normally carried out whilst the steel column is without significant axial load, the effectiveness of this method of jacketing is recognized widely. Repair and rehabilitation structural rehabilitation of. However, a fragile mode of failure with detachment of the strengthening concrete layer occurred in. Jacketing crack control free download as powerpoint presentation. Measurements were taken from jacketing and strengthened columns. The three columns represent existing column, current codedetailed column and rehabilitated column. Ijett steel jacketing technique used in strengthening. In this respect, this study focuses on the steel jacketing technique for retrofitting existing bridge columns to improve their seismic performance.
This paper describes experimental and theoretical studies on seismic retrofit of reinforced concrete circular columns with poor lapsplice details using prefabricated composite jacketing. The most common types of jackets are steel jacket, reinforced concrete jacket, fibre reinforced polymer composite jacket, jacket with high tension materials like carbon fibre, glass fibre etc. However, if there are architectural constraints rc jacket can be applied only in some sides of the column partial jacket. However, a fragile mode of failure with detachment of the strengthening concrete layer occurred in almost all cases. It was reported that compared to ferrocement jacketing, eccjacketed specimens exhibited enhanced ductility, energy dissipation and inelastic. Reinforced concrete jacketing retrofit method reinforced concrete jacketing is a traditional and one of the most common methods to retrofit andor repair reinforced concrete columns. Jacketing and collars for concrete column beam strengthening. Reinforced concrete structures often require strengthening to increase their capacity to sustain additional loads, due to change in use that resulted in additional live loads, deterioration of the load carrying elements, design errors, construction. Rc jacketing is a very effective strengthening method that allowed us to achieve up to 290% of strength increase.
Strengthened columns appeared to work as monolithic structures. A previous study of the columns with respect to the seismic requirements had shown that the confinement steel is inadequate and the shear capacity near the base of the columns is marginal. Jacketing fibre reinforced plastic reinforced concrete. Strengthening reinforced concrete columns by jacketing using. Research article materials and jacketing technique for retrofitting of structures shri.
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