REPAIR & REHABILIATION OF STRUCTURES

REPAIR & REHABILIATION OF STRUCTURES

POLYMER CONCRETE

PRESENTED BY:-

VIRAL SHAHUMANG SHAHSMIT SHAHSUMMARYWhy polymer concrete?What is polymer concrete?Types of polymers. QualitiesApplications UsesAdvantage, DisadvantageSuppliers, Manufacture in India.ReferencesINTRODUCTION

It is a common practise to construct the buildings with traditional concrete. In major cases of concrete deterioration, the problem is associated with corrosion of steel reinforcement.Therefore, whenever possible, it is desirable for both technical and economic reasons that deteriorated reinforced concrete should be repaired with impermeable highly alkaline cement based materials closely matched in properties to the parent concrete.Since last around 20 years polymer concrete is used in repair and rehabilitation of structures. But due to some extraordinary physical property of polymer concrete, it has great variety of application.Problem like wear, corrosion, low resistance to shock & frost action can easily be solve by using the polymer concrete, because polymer concrete has better resistance to shocks.

WHAT IS POLYMER CONCRETE?Polymer concrete (PC) is a composite material formed by combining mineral aggregates such as sand or gravel with a monomer.PC has following qualities:-Quick setting timeHigh strength properties Ability to withstand a corrosive environment.Material's lightweight natureZero percentage of water absorption. Stability toward the freezing-thawing cyclesMinimum wear from abrasion. Exceptional mechanical resistance (4x) enables production of small, lightweight elements.TYPE OF POLYMERSPPOLMER USE TO MODIFY CEMENTETIOUS SYSTEMREACTIVE THERMOSETTING RESINRESIN REPAIR MORTARUNSATURATED REACTIVE POLYSTER RESINUNSATURATED ACRYLIC RESINEPOXY RESIN Polymers used to modify cementitious systems

Since the early 1950s, it has been known that certain polymers can be added to cementitious mortars and renders to help overcome many of the problems of using unmodified mortars etc. as. concrete repair materials.The polymers used as admixtures for cementitious systems are normally supplied as milky white dispersions in water(latex) and are used to gauge the cementitious mortar as a whole or as partial replacement of the mixing water.Such mortars afford the same alkaline passivation protection of the steel as do conventional cementitious materials.It can be readily placed in a single application at 1215mm thickness which gives adequate protective cover

Polymers improve mortars in 3 waysImprove workability:-Making the mortar more fluid and easier to handle and apply. prolong the hydration period, which can increase working time, a water reducer, ultimately leading to a stronger mortar with fewer voids, or weak spots.Improved adhesion:-Act as an adhesive to enable the modified mortar overlay to stick to a variety of surfaces.Improved strength and durability:-Polymer-modified mortars generally have improved tensile strength, flexural strength, impact and abrasion resistance, water resistance, and chemical resistance versus unmodified mortars. REACTIVE TEHERMOSETTING RESINS 1. Resin repair mortarsWhere the cover is less than 12 mm and the areas to be repaired are relatively small resin mortars are being used extensively.It is important to note that the protection afforded by resin mortars is achieved by encapsulating the steel reinforcement with an impermeable macro coating which exhibits excellent adhesion to both the steel and concrete substrate.This protective mortar coating will give good long-term protection of steel reinforcement at thicknesses far less than is possible with cementitious repair materials.

The chemistry of the resin is, however, significantly different for each type

2. UNSATURATED REACTIVE POLYSTER RESINSPolyester resin systems are chemically much more simple in that the liquid resin component contains both the blocked hooks and the eyes in the right proportion intimately mixed together .The hardener (or catalyst) component is based on organic peroxide, which can be in the form of a fine powder, a low-viscosity liquid, or paste.

3. UNSATURATED ACRYLIC RESIN

Acrylic resin systems form high-strength materials by similar chemical cure mechanisms to the unsaturated resins.In general, acrylic resins are based on monomers of very low viscosity or blends of monomers with methyl methacrylate monomer, the most commonly used.Because of the very low viscosity of the uncured acrylic resins, so that the mortars tend to exhibit less shrinkage than mortars based on unsaturated polyester resinsThere are also available acrylic resins based on monomers such as 2-ethylhexacrylate.These produce mortars with significantly lower modulus which are, therefore, able to absorb the stresses due to their inherent shrinkage without causing bond failure with the concrete substrate.

CHARACTERISTICS Quick drainage of fluid This material, thanks to its completely smooth, mirror-like surface, facilitates quick drainage of fluids. It additionally offers a zero water absorption index versus the 5 10% of traditional concreteResistance to chemicals It is proven that polymer concrete is one of the most resistant materials to any type of chemical. This is because its components do not react to contact, thus avoiding separation or deformation of the product

CONTDWear from abrasion Polymer Concrete, because it is a compound material, guarantees perfect preservation of surfaces without any perception of wear from use or the passage of time.Resistance to shockThis material's properties, together with its optimum prefabricated design manage to withstand and absorb the force of the shock, thus guaranteeing great resistance to impacts.

APPLICATIONSPPRECAST BUILDING COMPONENTSPRECAST DRAINAGE SYSTEMPRECAST VENTILATED SYSTEMREPAIR & REHABILIATION OF STRUCTURENEW CONSTRCTION REPAIR & REHABILIATION OF STRUCTURELOCATION :- UNITED STATESTYPE OF STRUCTURE :- copper mine and refinery.PROBLEM: Their cell house, which contains over 1,500 cells, each holding more than 20,000 gallons of electrolyte, had experienced severe corrosion and structural degradation of the support columns for the tanks. Also, highly acidic leakage from the cells had corroded the support columns to the point that their ability to adequately withstand the imposed load was in doubt.

Figures illustrates the method by which the stainless steel bar was attached to the columns after surface-preparation. Stainless steel rebar was imbedded into the concrete floor using an epoxy mortar. To further ensure structural integrity and to upgrade seismic capabilities, the company chose to use fiberglass reinforcement (FRP) strips and wraps under the PC. The strips were installed vertically on the columns and a fiberglass fabric was wrapped around the columns horizontally. The columns were formed.

The polymer concrete was poured into place completely encapsulating the columns.The PC after the form has been removed and the FRP that was applied to the columns.

SOURCE :- POLYMER CONCRETE WHITE PAPER

AUTHOR :-David E. Snider Heather M. RamseyPRECAST BUILDINGSYSTEM

WINDOW SILLSLINTELSJAMBSBALCONY INFILLINGSSLAB FACESCOPINGMOULDINGPIER CAPSSKIRTINGS

PRECAST DRAINAGE SYSTEM It offers a range of solutions for channeling fluids and superficial rainwater collections and also for managing installations and services

PRECAST VENTILATED SYSTEM

It is a system for paneling buildings that combines appreciable aesthetic characteristics with efficient advantages in terms of insulation

A. SlabsB. Base protection (1/2 feet from perforated wall)C. Water-repellant mortarD. Thermal insulation.

USES OF POLYMER CONCRETEThese are some areas in which polymer concrete can be economically used.Flooring & pavement : Industrial and commercial flooring, warehouses, factories, stairways, hospitals, garages, railway platforms, airport runways etc. Water proofing : The low permeability of polymer concrete allows it to be used in swimming pools, water storage tanks, septic tanks, ship decks, basements etc.Patch & repair works : New mortar will not stick well to old concrete without polymer modification. so, we have the best option to use polymer concrete as a binder which will rest economical too.Decorative overlays : Polymer concrete offers very smooth surface. so, now a days it is widely used in wall coatings and textured building finishes.

ADVANTAGES OF POLYMER CONCRETERapid curing at ambient temperatures.High tensile, flexural, andcompressive strengths.Good adhesion to most surfaces.Good long-term durability with respect to freeze and thaw cycles.Low permeability to water and aggressive solutions.Good chemical resistance.Good resistance against corrosion.Lightweight.May be used in regular wood and steel formwork.Allows use of regular water reduce agentsDIS-ADVANTAGES OF POLYMER CONCRETEThe monomers can be volatile, combustible, and toxic. Initiators, which are used as catalysts, are combustible and harmful to human skin. The promoters and accelerators are also dangerous.

Polymer concrete also cost significantly more than conventional concrete.

SuppliersManufacturesSunrise polymer & ind. (BARODA)Build Core ChainIndo cool engg. Services(CHEENAI)Fairmate ChemicalsShantara Ind.(BARODA)Sugar polymerVasavibala Resin (CHEENAI)REFRENCESWWW.ULMAPOLIMERA.COMPOLYMER CONCRETE GUIDEPOLYMER CONCRETE WIKIPEDIAREPAIR & REHABILITION OF STRUCTURE BY ELLAN, EDWARDS & SHAW.POLYMER CONCRETE WHITE PAPER