Strengthening of reinforced concrete rc beams is required due to design errors, deficient concrete production, bad execution processes, damage due to earthquake, accidents such as collisions, fire, explosions and situations involving changes in the functionality of the structure etc. Reinforced concrete rc jacketing is always more frequently adopted to retro. In design process we must take two important points in considerations. Jacketing is the most popularly used method for strengthening of building columns. The most common method is to install the concrete on site, whereby iron reinforcements need to be embedded in the jacketing. Rc jacketing is a very effective strengthening method that allowed us to achieve up to 290% of strength increase. Pdf retrofitting comparative study of rc jacketing and. Rc jacketing is performed by placing additional reinforcement around the structural member and concreting it. Several methods are used but little information is available on the relative e.
Jacketing is one of the most common strengthening method for rc structural members. This can be made by longitudinal steel bars and additional concrete around an existing column or placing a jacket around the column. The external cable construction method is included under 9 prestressing introduction method in the retrofitting methods shown in figure c1. Conventional jacketing techniques include rc jacketing and steel jacketing. Repairing and strengthening methods for rc structural members. In concrete jacketing technique, rc members are wrapped with a jacket of. For a column strengthened using jacketing it is important to guarantee stress transfer at the new concrete old concrete interface.
Fixit micro concrete is supplied as a ready to use dry powder which requires only addition of clean water at site to produce a free flowing non shrink repair micro concrete. Inspect all materials used in the construction of concrete work at their source, on the job, or both. Research article materials and jacketing technique for retrofitting of structures shri. Pdf reinforced concrete rc jacketing is most frequently used to. It shows advantages particularly in seismic retrofitting, since it enhances strength, ductility and consequently the energy.
Jacketing is largely used as a strengthening s cheme of a member. Strengthening reinforced concrete columns by jacketing using selfcompacting concrete with different types of aggregates hamdy k. There are many different kinds of repairing and strengthening techniques in literature. Strengthening and repair of reinforced concrete columns. Khaloo2 1msc, sharif university of technology 2 distinguished professor, sharif university of technology corresponding authors email. Behavior of reinforced concrete columns strenghtened by. Materials for concrete repair, replacement and jacketing gopal mishra the materials used for concrete repair works such as replacement and jacketing of concrete structural members should have good bonding properties with the existing materials and should be nonshrinking. Strengthening reinforced concrete columns by jacketing using. This is a cementitious material, with additives, which impart controlled expansion characteri stics in the plastic. Effectiveness of various methods of jacketing for rc beams. The earliest proposed strengthening techniques such as steel jacketing or concrete incasing enhanced the seismic performance of the. It improves axial and shear strength of column and major strengthening of foundation may be avoided. Repair and rehabilitation structural rehabilitation of.
Thus, the strength of the structures can be moderately or significantly increased and the. Pdf retrofitting of existing rcc buildings by method of. Building code requirements for structural concrete aci 31811 and commentary first printing august 2011 isbn 9780870317446 american concrete institute. Structural rehabilitation of columns with reinforced concrete jacketing. Strengthening column using micro concrete jacketing. Retrofitting existing concrete elements by method of jacketing solutions horse construction business range tend to all over the world and service for thousands clients with products, technical,construction specialized guidance, and we witness the chinese reinfocing brands togther with them. Introduction repairing of reinforced concrete elements is required after a damage.
Apr 07, 2018 strengthening column using micro concrete jacketing remove entire plaster to reach parent concrete surface if the column is plaster. Epoxy mortar mixture has higher compressive strength, higher tensile strength and a lower modulus of elasticity than portland cement concrete. Fibre reinforced polymer frp jacketing in jacketing of structural elements, modern techniques are also available that use fibre reinforced polymer frp sheets for enhancing the strength of. Each one of these methods has its difficulties regarding the new construction forms needed and the modification in. Jacketing is a technique used to increase the strength of existing structural members e. Strengthening of reinforced concrete structure elements using concrete jackets 3. Pdf reinforced concrete jacketing interface influence on cyclic. Though this method doesnt much increase the column sizes relative to concrete jacketing, nevertheless, increase in stiffness could be significant. Strengthening of reinforced concrete columns by reinforced concrete jacket project recommendations andre filipe da silva henriques instituto superior tecnico andre. Regarding the strengthening of existing columns, the.
Design and detailing of rc jacketting for concrete columns. Strengthening such elements is a method to increase the earthquake resistance. Five commonly jacketing techniques are used for strengthening the rc columns in. Guidelines for external prestressing as strengthening. The size of the jacket and the number and diameter of the steel bars used in the jacketing process depend on the. A practical approach for the strength evaluation of rc. 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. One way of retrofitting the columns is by concrete jacketing. Effect of steel plate jacketing of columns in seismic behavior of concrete beamcolumn connections m.
A common strengthening technique for reinforced concrete structures consists of jacketing the member by adding new concrete to its sides increasing the size and resistance of the cross section. Concrete basicsaims to provide a clear, concise explanation of all aspects of making quality concrete. Measurements were taken from jacketing and strengthened columns. Reinforced concrete jacketing is a current strengthening method of reinforced concrete columns. This method is evaluated according to different characteristics and, in order to help structural engineers to choose the most appropriate solutions, recommendations are given, based on published experimental research and real case studies. Effect of steel plate jacketing of columns in seismic. Methods of strengthening concrete columns the constructor. Deflections along the column length as well as crack development were also monitored. Pdf reinforced concrete rc jacketing is most frequently used to strengthen columns. This method consists in casting a concrete layer around the existing member, and reinforcing the jacket with a properly designed amount of longitudinal and transverse reinforcement fig. The results of both the assessment redesign of the reinforced concrete structures as well as the design of loadbearing masonry structures are also presented in a wellorganized, format. In the following paragraphs, this method is assessed according to different aspects. The question to be answered was how the effectiveness of the technique alters when common as used in practice procedures are performed. 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.
For this reason, it leads to a reduction of deflections, stresses, and cracks in structural members. Concrete jacketing is a commonly used method to retrofit or strengthen existing columns for axial loads. A new steel jacketing method for rc columns article pdf available in magazine of concrete research 6110. The concrete composition must be established in order to assure the resistance and durability of building elements, by using less cement dosage. Arafa4 1professor of reinforced concrete, department of structure engineering, zagazig, egypt. Received april 27, 2009 accepted may 5, 2009 concrete jacketing is a commonly used method to retrofit or strengthen. Jacketing consists of added concrete with longitudinal and transverse reinforcement around the existing column. When, why and how to rehabilitate a structure when. It was demonstrated that steel plates bonded to the tension mlmce 5 civil engineering retrofitting of existing rcc buildings by method of jacketing face of the concrete beams can lead to increase in flexural capacity, along with increase in flexural stiffness and associated decreases in deflection and cracking. Now by tapping with a light hammer, identify of loose concrete portions are present. Retrofitting is a technique to enhance the structural capacities. The drawback with this method is that the soft insulation of the steel pipe can be damaged during the installation of the steel reinproducing concrete jacketing. The overlaying and jacketing construction method is a retrofitting method in which concrete sections are added and corresponds to 2 overlaying construction method and 3 jacketing construction method in the figure. Unlike the other mentioned techniques, external prestressing is an active strengthening technique.
In the seismic retrofitting of reinforced concrete. It is well known that the success of this procedure is dependent on the monolithic behavior of the composite element. Introduction to repair and strengthening of reinforced concrete structures 1. Pdf reinforced concrete jacketing interface influence on. Pdf reinforced concrete jacketing interface influence. The common practice to prepare the interface is empirically.
Concrete jacketing involves placing an additional layer of concrete covering the existing column, together with additional longitudinal bars and ties to enhance the flexural andor shear capacities. Pdf following previous studies, the authors describe an experimental study. Retrofitting existing concrete elements by method of jacketing. Repair and strengthening of reinforced concrete structures.
You can file concrete to give it a more finished appearance, smooth out rough edges or even to create artistic sculptures. Jul 03, 2017 jacketing is a technique used to increase the strength of existing structural members e. Reinforced jacketing, carbon fiber and reparation with steel plates are the ones that are used the most. Concrete jacketing, for example, is one of the most. Concrete jacket construction detail effectiveness when. Mechanical performance and applications ahmed elbadawy sayed, assoc. Jacketing is one of the most frequently used techniques to strengthen reinforced concrete rc columns. There are two processes for applying sprayed concrete dry mix sprayed concretein which most of the mixing. 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 investigation of reinforced concrete columns. Strengthening rc columns by jacketing using ultra high. Generally when filing concrete, you should use a rasp instead of a regular file because the larger teeth or grit on the rasp are better suited to the rough texture of the concrete.
Research article materials and jacketing technique for. The concrete composition is established by the next parameters. Rc elements, different techniques are usually proposed. The retrofitting of columns by concrete jacketing is not sufficiently documented. At first, 45 concrete cylinders were fabricated with varying design compressive strengths of 21, 27 and 35 mpa and then part of them was jacketed with two split. Materials for concrete repair, replacement and jacketing.
1154 1393 634 973 292 927 724 318 215 509 1261 186 966 1354 1005 1444 889 265 1009 1278 275 1217 680 804 328 1353 91 1070 471 666 868 1364 146 350 1473 607 868 62 320 66 198 690 1145 363 310