Modern Approach to Structural Strengthening
01 Sep 2011
Conmix has launched a system of structural strengthening with carbon and glass fibre.
The construction industry forms a vital component of any economy. Development of infrastructure like rails, roads, bridges, tunnels, dams, airports etc; commercial sectors like residential towers, recreational amenities, malls, etc; and industrial production units require huge financial investment and serious planning. With the evolution of the Green Building concept, it is evident that the construction industry is reaching new levels of advancement in the global scenario.
In the current environmental scenario, concrete structures are exposed to many aggressive elements like industrial pollutants, harmful gases, chemicals, etc and adverse weather conditions. Effects of these elements, coupled with impact and abrasion, deteriorate the concrete structures. Demolishing the damaged structure and rebuilding is not only an expensive activity, but also a major waste of resources. Hence, concrete repair systems become inevitable to rehabilitate the damaged concrete structures so that their usable life span can be extended.
Sometimes, there is a change in the purpose of utilisation of the structure, resulting in change of the loading pattern. This in turn, necessitates change in designs wherein strengthening of existing columns, beams and slabs is needed. Conventional practice involves jacketing and
fixing the steel plates to increase the section of the element. Jacketing involves fixing of additional reinforcement, shuttering and pouring micro concrete. This is not only a tedious and time consuming method but also results in reducing clear span or reduced carpet area. Steel plates are likely to corrode over a period of time. Also, it is difficult to apply plasters and renders over steel plates. Both of the above methods result in increased dead load over the existing structure.
To overcome these challenges, a new system of strengthening structural elements with carbon and glass fibres has come into existence. Although carbon fibres have been in use since decades in aircraft, electronics, automobiles, computers, etc, their utilisation in the construction industry is relatively new.
Conmix Construction Chemicals has made these techniques available through their products like ReCon Wrap CF (carbon fibre wrapping system), ReCon Wrap GF (glass fibre wrapping system) and ReCon Plate CFL (preformed carbon laminates).
ReCon Wrap CF along with thermoset resin (ReCon Wrap Saturant) can be used to improve the load bearing capacity of a column through confinement by 100 per cent to 300 per cent. ReCon Plate CFL, popularly known as externally bonded FRP laminates can be used to increase the shear and flexural strength of beams.
ReCon Plate CFL consists of carbon plates of various sizes. Smaller sizes (width) can be used as an NSM (near surface mounted) technique. In this technique, carbon plates or rods are inserted in grooves cut in concrete cover of the element. These are fixed with specially developed epoxy adhesives, ReCon Plate adhesive or even NanoGrout SG Paste.
Structural strengthening with ReCon Wrap CF and ReCon Plate CFL is fast gaining popularity due to its distinct advantages. These materials are corrosion resistant. They can be applied on elements with any shape and size. They can be applied with ease in areas that are difficult to access. Installation is very fast, which reduces effective down time. They are applied in very minimal thickness (in millimetres), which results in very high load-to-thickness ratio. These materials improve the load bearing capacity of the structural elements significantly without increasing the dead load on the structure. ReCon Plate CFL laminate acts as an additional reinforcement, which helps in overcoming design deficiency. These materials can be plastered and painted over easily.
ReCon Wrap CF has been used in many critical projects in the UAE and abroad for strengthening basement columns of upto 40 storeys, tall towers, G+2 structures, etc. ReCon Plate CFL has been used to stop the deflection of slabs and strengthening of such beams.
Conmix Construction Chemicals division manufactures a comprehensive range of repair products, floorings, nonshrink grouts, waterproofing, sealants, curing compounds, admixtures, mould release agents, bonding agents, tile adhesives and tile grouts. The company follows a quality management system certified to ISO 9001, maintaining quality assurance in design, development, production, installation and service.
Conmix products comply with all international standards and are used in more than 32 countries. Supported by modern and substantial manufacturing units, well equipped R&D facility, state of art laboratories, experienced qualified engineers, competent technical support department and proactive sales team, Conmix is indeed an ideal partner for all construction needs.
(Communication by the management of the company)