Jacketing Method Research Articles

ANALISA PENGUATAN STRUKTUR PENAMBAHAN LANTAI BANGUNAN GEDUNG (STUDI KASUS DI DPMPTSP KAB. KUDUS)

The research was conducted in the Kudus Regency Public Services building which originally had a floor area of 1172 m2. In 2022 there will be development, so a new floor will need to be added. Where the land area cannot be used to build horizontally, add vertical floors to a 2-story building to become 3 floors. The research was carried out by testing the quality of concrete using the Hammer Test, obtaining a result of 20.75 MPa, then modeling analysis was carried out using SAP 2000 v14 software and manual calculations based on SNI 03-2847-2002, SNI 031726-2012, and SNI 1729-2015. This analysis was carried out in 3 stages, the first was an analysis of the initial conditions of the existing building, the second was an analysis of the existing structure with the additional load of the new floor, and the third analysis was with the additional load and structural strengthening. The results of the structural analysis stages 1 and 2 stated that the beam structural elements experienced overstrength (O/S) or could not withstand the additional load of the 3rd floor. With this data, structural reinforcement calculations were carried out using the concrete jacketing method with a number of longitudinal reinforcement 7D16 stirrups Ø10-100 for beams and the amount of longitudinal reinforcement 8D19 stirrups Ø10-100 and the method of strengthening with steel profile IWF 200.200.8.12.

KAJIAN TEKNIS GEDUNG BETON BERTULANG DAN PERENCANAAN PERKUATANNYA

Changes in the function of existing buildings with changes in load functions that exceed the design load cause structural failure. The impact of structural failure varies from light to moderate, to severe damage and collapse. Thus, structural failure requires efforts to strengthen the structure with good reinforcement methods that are easy to carry out on-site. The existing building studied is the Villa Minggu Seminyak building, which is located on Jl Kunti, Gg Mangga, Seminyak, Kuta, Badung, Bali. To get good and easy-to-do reinforcement results, an investigation is carried out to obtain data on damage to existing buildings, and then analysis and evaluation are carried out. Models and analyses were carried out in 3D using SAP2000 software. The purpose of this research is to determine the behavior of existing structures before and after strengthening. The strengthening method used for column structural components is the Concrete Jacketing method. The results of the analysis show that the capacity of the existing beams and columns is insufficient, where the existing beam B1 reinforcement area of 896.47mm2 is smaller than the required reinforcement area of 1023 mm2, the axial force capacity and ultimate moment of column K1 are outside the interaction diagram and the structure's vibration time is 1.193 seconds smaller than allowable vibration time of 0.351 seconds. Thus, strengthening of the beams and columns is required. The results of the analysis and design show that concrete jacketing reinforcement requires 10 cm thick concrete with 16D13 mm main reinforcement and Ø10-75 mm stirrup reinforcement. This reinforcement can increase the axial load capacity of the column by 314.5%. Strengthening the beam with the addition of WF Steel was able to increase the ultimate moment of the support by 38.7% and the ultimate moment of the field by 39.6%. The ultimate shear force increases by 121.4%. By strengthening the columns and beams, the vibration time of the structure has a shorter duration of 48%, so the structure becomes stiffer.

Rehabilitation of Severely Damaged RC Bridge Piers: Experimental and Numerical Investigation

ABSTRACT This study explored rehabilitation of severely damaged bridge pier models using reinforced concrete jacketing method adopting a plastic hinge relocation technique. The test specimens were tested under cyclic loading. The important seismic performance parameters were evaluated for the rehabilitated specimen. A 3D finite element model was simulated considering concrete-rebar interaction and jacket-pier interface shear. Calibration of the numerically simulated model was done by comparing with experimentally observed responses. Additionally, a parametric study was conducted to investigate the effect of shear connectors on performance of the rehabilitated test specimen.

Improved Shear Strength Equation for Reinforced Concrete Columns Retrofitted with Hybrid Concrete Jackets.

The adequacy of retrofitting with concrete jacketing is influenced by the bonding between the old section and jacketing section. In this study, five specimens were fabricated, and cyclic loading tests were performed to investigate the integration behavior of the hybrid concrete jacketing method under combined loads. The experimental results showed that the strength of the proposed retrofitting method increased approximately three times compared to the old column, and bonding capacity was also improved. This paper proposed a shear strength equation that considers the slip between the jacketed section and the old section. Moreover, a factor was proposed for considering the reduction in the shear capacity of the stirrup resulting from the slippage between the mortar and stirrup utilized on the jacketing section. The accuracy and validity of the proposed equations were examined through a comparison with the ACI 318-19 design criteria and test results.

Response of reinforced concrete structural members exposed to high temperature fire and retrofitting of fire damaged structural members adopting R.C jacketing

When fire breaks out in a building, the most important criteria is the retention of stability of the fire damaged structure against partial or total collapse. An actual case study has been presented in the current work on the response of structural elements present in a 12 storey RC multi storied building exposed to high temperature during a fire event taken place in it. The rise of the temperature in the structural elements in the event of a fire exposure, causes physio-chemical changes in the materials the structural members are made up of, namely, concrete and reinforcing steel, leading towards the degradation of material stiffness, elastic modulus and decrease in the load carrying capacity of such structural members. In the present work, two compartments at the periphery of the building are exposed to high temperatures of 300 °C, 500 °C and 700 °C, and the structural analysis is carried out with dead load, live load and temperature. Structural response of the structural members is assessed, as well as maximum displacements, internal forces developed in them as a consequence of exposure to high temperature has been recorded. As per observation, a combination of temperature and gravity loads(DL&LL), increases the probability of the structure to undergo a higher degree of damage, as the restrained structural members due to the effect of temperature, undergo nonlinear deformations (buckling of columns and bowing action of beams). Reinforced concrete columns and beams that might have undergone a repairable degree of damage due to different temperatures have been retrofitted adopting the RC jacketing method. It is observed from the results of the present case study that, by adopting RC jacketing to retrofit temperature damaged structural members, present in the structure, an enhancement in the stiffness and overall stability of the structure is observed to further withstand externally applied loads.

Strengthening of a Damaged Concrete Structure - Case Study of an Eleven Stories Building in Dar es Salaam

Concrete structures may become obsolete and be unfit for use to the extent that they need special attendance of repair or strengthening so as to revive them. The weakness in the buildings may be caused by natural disasters like earthquake, floods, changes of use of the buildings in which higher loads more than the design loads, e.g. vertical extension loads, are applied. When the structures are defective they need to be strengthened in order to restore their original structural integrity. Sometimes, the defect or deterioration needs to be scientifically analysed first in order to know the root cause of the problem and apply the right corrective measures. A case study on an eleven stories damaged building in is presented, starting with an investigation on causes of sudden crushing of one column and a strengthening method which embraced a number of techniques such as Land Surveying and non-destructive tests in assessing the building structural integrity. The crushed column and other columns is the ground floor were all strengthened using jacketing method and provision of additional columns at the crushed column. Keywords: Columns, crushing, non-destructive tests, concrete quality, deflection, plumb, jacketing, strengthening

An Experimental Study on Torsional Behavior of Reinforced Concrete Columns Retrofitted with Hybrid Concrete Jackets.

The concrete jacketing method for retrofitting old reinforced concrete (RC) columns should secure confinement and seismic performance under torsion as well as unidirectional later loads. In a previous study, a hybrid concrete jacketing method was proposed using steel wire mesh (SWM), steel grid reinforcement (SGR), which can replace reinforcement of existing concrete jacketing method, and using steel fiber non-shrinkage mortar (SFNM). These details can simplify the retrofitting process of the existing concrete jacketing method, and seismic performance was evaluated by conducting a cyclic loading test under unidirectional loading. In this paper, the torsional behavior of RC columns retrofitted with the hybrid concrete jacketing method was investigated. Four specimens were fabricated and conducted cyclic loading tests under two types of loading schemes, unidirectional and bidirectional loading, to examine the effect of the loading path. The strength and energy dissipation capacity of retrofitted columns with hybrid concrete jackets increased approximately eight times compared to the old RC columns under torsional loading. Therefore, the hybrid concrete jacketing method can improve torsional resistance.

A comparative study on the seismic performance of RC beam-column joints retrofitted by ECC, FRP, and concrete jacketing methods

Reinforced concrete (RC) beam-column joints in many old buildings do not have appropriate seismic detailing that allows them to provide sufficient strength and stiffness in strong seismic events. To improve the seismic performance of these deficient beam-column joints, this study proposes a new retrofitting method based on high-strength steel bar mesh and Engineering Cementitious Composite (ECC), a fiber-reinforced cementitious material that shows high tensile ductility and damage tolerance. The proposed method reduces the required size of the retrofitting jacket through the combined use of ECC jackets and high-strength steel bar mesh. The performance of the proposed ECC jacketing method was compared with that of concrete jackets and fiber-reinforced-polymer (FRP) jackets. Experimental program included cyclic testing of four exterior beam-column joints, i.e., one control specimen and three others retrofitted using ECC, concrete, and FRP jacketing. Results showed that (1) reinforced ECC jackets confined the joint core and prevented localized damage in the joint zone via formation of dense and fine cracks, (2) the beam-column joint retrofitted using ECC jackets with high-strength steel mesh exhibited the favorable beam flexural failure, while the other three joints showed joint shear failure, (3) compared to other two retrofitting methods, the reinforced ECC jacket more effectively increased the strength, stiffness retention, energy dissipation capacity, deformation capacity, and collapse drift. In addition to experimental study, suitable strength models were suggested to evaluate the strength and failure patterns of the retrofitted exterior beam-column joints.

Seismic performance of full-scale UHPC-jacket-strengthened RC columns under high axial loads

Ultra-high-performance concrete (UHPC) is a class of concrete materials that have high strength and ductility capacities. This study developed two UHPC jacketing methods to improve the seismic performance of shear-deficient RC columns in mid- to high-rise buildings without enlarging the cross-section of the columns. In the first method, the original concrete cover was replaced with a cast-in-place UHPC jacket that was reinforced by steel bar mesh. To simplify the on-site construction process, the second method utilized prefabricated UHPC panels incorporating steel bar mesh. The performance of the proposed strengthening methods was evaluated using cyclic loading tests on three full-scale RC columns with a high axial load demand. The test results showed that the developed UHPC jacketing methods improved the lateral strength and drift capacity of the shear-deficient column by at least 40% and 30%, respectively. They also reduced the residual displacement of the column by 65%-80%. Compared to the cast-in-place jacketing, the discontinuity in the prefabricated UHPC jackets inhibited full composite action of the jacketing, thus reducing the retrofitting efficiency. In addition to the experimental study, evaluation methods were proposed to evaluate the strength and behavior of the retrofitted columns.

Performa Struktur Kolom Pasca Perkuatan Dengan Metode Concrete Jacketing Bertulangan Bambu

Kolom adalah elemen terpenting dalam sebuah struktur. Berdasarkan peraturan beton Indonesia SNI 2847-2013 disebutkan bahwa kolom merupakan elemen yang menerima beban aksial minimal 0,1 Pu serta beban lentur. Kerusakan pada kolom dapat terjadi akibat adanya beban berlebih yang diterima, desain pendetailan yang buruk, pelaksanaan konstruksi yang buruk, dan lainnya. Namun, yang paling sering terjadi adalah kerusakan pasca gempa. Perkuatan yang paling mudah dilakukan adalah metode pelapisan beton. Tulangan pada perkuatan yang digunakan dalam penelitian ini adalah bambu. Metode pengujian dilakukan dengan metode Quasi Static Loading Test dengan beban lateral sesuai dengan kontrol perpindahan dan juga beban aksial konstan. Hasil penelitian menunjukkan bahwa perkuatan pelapisan beton dari dimensi awal 15x15x90 cm menjadi 21x21x90 cm menunjukkan peningkatan kapasitas lateral, keuletan, kekakuan, dan disipasi energi. Selain itu terlihat bahwa perkuatan pada kolom rusak dan kolom tidak rusak kurang signifikan, yang berarti perkuatan dapat mengembalikan kapasitas awal benda uji eksisting hingga melebihi 100%.

Kuat Tarik Interfase antara Beton Lama dan Beton Baru dengan Variabel Beton Geopolimer dan Beton Konvensional

SCGC Concrete (Self Compacting Geopolymer Concrete) has the advantage of being easier and more effective in casting, so it can be applied to strengthening building structures, including the Concrete Jacketing method and voute / haunch beam. This reinforcement method is a form of composite concrete application with different concrete ages, which consists of existing structures with conventional concrete material and jacket or haunch section with SCGC concrete material. This study aims to determine the characteristics in the form of direct tensile strength, flexural tensile strength, and pull off tests (bond test) to test the strength of adhesion between concrete joints. Making specimens consists of 4 x 4 x 16 (cm) flexural tensile test beams, and 15 x 15 x 60 (cm) pull off specimens, and direct tensile specimens in the form of numbers 8. The principle of making test specimens is done by casting twice The first casting is done on the first half of the mold, then wait until the concrete age is 28 days. Then a second casting is carried out in the next half, until the concrete age is 28 days. So that the total age of concrete in making connection test specimens is 56 days. From the results of this study it was found SCGC concrete has a higher adhesion than conventional concrete so that SCGC concrete can be applied for structural reinforcement.

Axial performance of RC columns strengthened with different jacketing methods

This study aims to examine the potential of approaches proposed for transverse reinforcement arrangement in the jacket section of existing non-seismic or deficient columns to enhance the axial performance of these columns. To satisfy the requirements for the seismic details of column design specified in ACI 318-14, an original technique of arranging V-clips across the overlapped legs of channel-shape bars was proposed to form peripheral closed-hoops in the jacket section while avoiding the interruption of the existing column. Ten column specimens with large-scale dimensions were prepared by considering the jacketing method and the amount of transverse reinforcement in the jacket section as test parameters, following which they were tested under concentric axial loads by using a 40000-kN-capacity steel frame. In the test, concrete jacket columns prepared using the proposed V-clip technique showed an axial performance equivalent to that of the counterpart concrete jacket columns prepared using prefabricated bar units, the effectiveness of which was previously demonstrated in terms of the enhancement of axial stiffness, strength, and ductility as well as easier buildability for forming peripheral closed-hoops and supplementary ties in the jacket section. The restriction of the opening of the channel-shape bars by V-clips delayed the buckling of longitudinal reinforcing bars and resulted in less severe damage to the core concrete in the jacket section. Thus, concrete jacket columns reinforced with the proposed techniques exhibited higher values of axial ductility than conventional concrete jacket columns or columns jacketed with steel plates and carbon-fiber laminates.

Effect of Length Development on Concrete Jacketing Method with Bamboo Reinforcement of Flexural Capacity Reinforced Concrete Beam

Effect of Length Development on Concrete Jacketing Method with Bamboo Reinforcement of Flexural Capacity Reinforced Concrete Beam

Seismic retrofitting analysis using concrete jacketing and shear wall on dental hospital building of Andalas University

Due to some damage to the structural elements of Andalas University Dental Hospital building, an evaluation of the building structure was carried out. Based on the structural evaluation using Indonesian standard code, SNI 03-1726-2012, it was found that the building is not strong enough to resist the combination loads acting on the structure, especially seismic load. Therefore, the structure should be seismically improved. In this study, there are two retrofitting methods are proposed and analysed: adding concrete jacketing and shear wall. The concrete jacketing method was conducted by enlarging the cross-sectional dimensions and adding reinforcement bar to the structural elements (beam and column) that are unable to resist the working loads. By using the concrete jacketing method, there are many structural components must be strengthened. Therefore, another retrofitting method is proposed, by adding the concrete shear wall. Shear wall is specially designed structural walls include in the buildings to resist the horizontal forces that induced in the plane of the wall due to earthquake forces. From the analysis, it is concluded that the two retrofitting methods are effective enough to reduce the internal forces and displacement of the building. Considering the more effective and efficient work, retrofitting method using shear wall was recommended for strengthening the Dental Hospital building.

AXIAL BEHAVIOR OF RC COLUMNS RETROFITTED USING BAMBOO REINFORCED CONCRETE JACKET

Weak or damaged reinforced concrete columns need to be retrofitted in order to increase the strength capacity and ductility. Concrete jacketing is one of the most common techniques adopted for such purpose due to its relatively simple and low-cost application. However, the dependency on steel reinforcement in its use is still high and with the sustainability issues that are getting more important nowadays, the idea of bamboo as a replacement for steel as reinforcing bars in the concrete jacketing method has been investigated in this experimental study. A group of short reinforced concrete column specimens with axial load failure state were then retrofitted with a variety of longitudinal and transversal bamboo reinforcement configurations of concrete jacketing and subjected to further compression axial load test. The axial load-displacement behavior, axial strength capacity, and collapse mechanisms were recorded and analyzed. The outcomes showed that bamboo reinforced concrete jacket perform satisfactorily by restoring the axial load capacity and increasing ductility of column specimens providing that the bamboo stirrups spacing was set closer than that of the original column.

The Effect of Structure Performance on RC Strengthening Using Concrete Jacketing Method

The Effect of Structure Performance on RC Strengthening Using Concrete Jacketing Method

Sprayed Glass Fiber–Reinforced Mortar with or without Basalt Textile Reinforcement for Jacketing of Low-Strength Concrete Prisms

AbstractThe external jacketing method using cement-based matrices and textile reinforcement has gained popularity for the enhancement of strength and ductility characteristics of reinforced concret...

Strengthening method of concrete structure

Building extension in Indonesia is not favored, and not many people know the advantages of the method because architects and engineers tend to lack the knowledge and experience. The aim of this paper is to explain a method on how to strengthen a concrete building structure that people can use/learn as a better way to cut potential cost and save time. The strengthening method explained in this paper is steel jacketing, providing a case study of this method in the extension of a restaurant located in Medan, Indonesia. In this study, engineers calculated that the tensile stress of the existing RC column and beam is not strong enough to reinforce the building extension applied load. Therefore, the steel jacketing method can be applied to improve the column and beam strength and ductility. The result of the case study proves that this is one of the best methods for building extension applied in Indonesia.

Proposals of Reliable Shapes of Supplementary V-ties for Section Jacketing Method of Columns

Proposals of Reliable Shapes of Supplementary V-ties for Section Jacketing Method of Columns

Strengthening of Nurul Ilmi Mosque with Concrete Jacketing

Abstract—Nurul Ilmi moesque is one of building for worship located in University of Andalas. In 2008 the new building of mosques was designed using previous indonesian seismic code, SNI 1726: 2002. The right side of the new mosque was constructied in 2009. Due to the limitation of the budget, the construction of the left side of the mosque was continued on 2014. However, a new indonesian seismic code SNI 03-1726-2012 was established and the designed mosque should be revised based on the new indonesian seismic code. Since the right side of the mosque was designed by using the old seismic code (SNI 1726: 2002), so it is necessary to evaluate the strength of the structure by using the seismic code (SNI 03-1726-2012). Based on the analysis results, it was found that the right side of the building structure is not strong enough to resist the combination loads acting on the structure, especially the earthquake load. Therefore, it is necessary to strengthening (retrofitting) the right side of the building structure before connecting with the left side of the building. In this study, the concrete jacketing method was used to the retrofit the column structure. The results show that the jacketing method is effective to increase the capacity of the column and reduce internal forces and displacements that occur in the structure of the mosque, so the structure can resist the working loadsKeywords—column, concrete jacketing, earthquake, displacement, strengthening.