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Polymer concrete
- 1. PRESENTED BY :RAVIKIRAN KATTOLI
- 2. Cement concreteis an inherently porous material and as such, it has a low tensile strength. It exhibits a tendency to cracks and can deteriorate under the influence of severe chemicals in the atmosphere or in Solution. Concrete polymer materials have been developed during the last fifteen years in a number of laboratories around the world. For applications as a constructional material offering the potential advantages of a higher strength, water tightness, and improved durability and resistance to freeze-thaw cycles over normal portland cement concrete. The production of polymer-concrete composites involves the introduction of chemicals within the pores of the concrete and their polymerization.
- 3. Polymer concreteis a part of group of concretes that use polymers to supplement or replace cement as a binder.
- 4. The composites usingpolymer can be: 1. Polymer concrete (PC), when the binder is a polymer that replaces the cement paste 2. Polymer modified concrete (PMC), when the polymer is mixed along with cement 3. Polymer impregnated concrete (PIC), when the cement concrete is treated by soaking and polymerization. 4. Partially Impregnated And Surface coated polymer concrete.
- 5. Polymer concreteis a composite material which results from polymerization of a monomer and aggregate mixture. The polymerized monomer acts as binder for the aggregates and the resulting composite is called “Polymer Concrete.” Two techniques are used to mix monomer with aggregate. The first is the conventional method of adding monomer to dry aggregate and stirring until a uniform blend is achieved. The second technique consists of placing the monomer in the specimen mould and then gradually adding aggregate to the monomer. The mixture is Consolidated by mechnical Vibration.
- 6. Rapid curingat ambient temperatures Good long-term durability with respect to freeze and thaw cycles Low permeability to water and aggressive solutions Good resistance against corrosion DISADVANTAGES It tends to be brittle in nature i.e. if fiber reinforcement is not provided in some polymer concrete cases they tend to develop cracks. Among the disadvantages is their high cost.
- 7. It isalso known as polymer cement concrete Polymer modified concrete is gaining popularity because of its ease of handling, economy and satisfactory results Low water absorption and permeability make it an effective material for use in hydraulic structures as well. It has the property of setting quickly.
- 8. The mostimpressive characteristics of PMC are its ability to bond strongly with old concrete, and to resist the entry of water and aggressive solutions. Epoxy resin produced a concrete that showed some superior charecteristics over ordinary Portland cement. DISADVANTAGE Modest improvement of strength and durability
- 9. Polymer-Impregnated Concrete(PIC) is generally, a precast and hydrated portland cement concrete, which has been cleaned, dried (eventually evacuated) and impregnated with a low viscosity monomer (eventually soaked under pressure) before being polymerized. The most appreciable improvements in the structural and durability properties have been obtained with PIC. The unique feature of impregnating concrete is that a large part of the voids volume in the capillary pores is filled with the polymer and forms a continuous internal reinforcing structure which is thus responsible for the remarkable improvement in strength and durability.
- 10. The mechanicaland chemical resistant properties of PIC composites are superior to the conventional cement mortar. Porosity of the conventional cement mortar is greatly reduced when it is impregnated with polymers thereby increasing its durability. The presence of the polymer in a PIC not only envelopes the cement mortar but also seals the voids formed during the cement hydration. Compressive strength increases and is different for different composition and on type of polymers used. Tensile strength increases and is different for different composition and on type of polymers used.
- 11. The partiallyimpregnated concrete can be easily produced by initially soaking the dried specimens in the liquid monomer ,then sealing them by keeping them under hot water at 70°c to prevent or minimize loss due to evaporation. Partial impregnation may be sufficient in situations where the major requirement is surface resistance against chemical and mechanical attack in addition to increase in its strength. The depth of monomer penetration depends upon Pore structure Duration of soaking Viscosity of the monomer
- 12. It reducesfreeze thaw deterioration, corrosion Increase in tensile strength Increase in compressive strength Increase in modulus of elasticity Resistance to acid attack It improves the durability of concrete Less pores
- 13. structural floors swimming pools Pipes storage tanks for distilled water anti-abrasive surface marine structures tunnel liners telephone cable ducts
- 14. Curing timestudies on polymer concrete have established that it achieves around 70% of its strength after a curing of one day at room temperature. Durability studies on polymer concrete have established its superiority over conventional cement concrete. Exposure to water, chemical agents etc. has very less deleterious effect on properties of polymer concrete when compared to cement concrete.
- 15. Polymers inConcrete, American Concrete Institute Publications SP-40, Detroit, Michigan 1973, SP-58, Detroit, 1978 2. Concrete-Polymer Materials, Five Topical Reports, Brookhaven National Loboratory and USSR 1968-1973 State-of-the-Art Report, Polymers in Concrete, ACI Committee, 548 Report, American Concrete Institute, Detroit, Michigan, 1977 PATUROEV, V.V., Technology of Polymer Concretes, Stroyzdat Press, USSR, 1977 P.K. Mehta And P.J.M. Monteiro, Concrete: Microstructure, Properties, And Materials Concrete Technology By M.S.Shetty