Construction Assignment | Use of Polymers

Added on - 10 May 2020

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The Use of Polymers in Road Construction1A RESEARCH PAPER ON THE USE OF POLYMERS IN ROAD CONSTRUCTIONA Research Paper on Polymers ByStudent’s NameName of the ProfessorInstitutional AffiliationCity/StateYear/Month/Day
The Use of Polymers in Road Construction2Contents1.0 Introduction:..........................................................................................................................................21.1 Background research about types of polymers used in road construction..........................................31.2 Background study on Bitumen...........................................................................................................32.0 Types of polymers.................................................................................................................................32.1 Thermoplastic elastomers..................................................................................................................32.2 Thermoplastic polymers....................................................................................................................42.3 Thermosetting polymers....................................................................................................................43.0 Literature review:..................................................................................................................................53.1Thermoplastic elastomers............................................................................................................53.1.2Styrene–butadiene–rubber (SBR)...............................................................................................73.1.3 Styrene Isoprene styrene.............................................................................................................83.1.4 Natural rubber.............................................................................................................................83.2Thermoplastic polymers:.............................................................................................................93.2.1Ethylene Vinyl Acetate (EVA)....................................................................................................93.2.2 Polypropylene...........................................................................................................................103.2.3 Polyethylene (PE).....................................................................................................................113.2.4 Polyvinyl Chloride: -................................................................................................................123.3Thermosetting polymers:...........................................................................................................133.4 Application of polymers..................................................................................................................154.1 Summary table;................................................................................................................................164.2 Matrix table.....................................................................................................................................175.0 Conclusion and Recommendations......................................................................................................18References:................................................................................................................................................19
The Use of Polymers in Road Construction31.0 Introduction:Engineers and scientists are looking for the methods to improve the road performance. For strongand rigid roads concrete is used and bitumen is used in the flexible roads. The steady trafficincrease in terms of the vehicles for commerce and variation of the seasonal and dailytemperatures demand the improved characteristics of the roads and the improvement of the of thebinder properties. In the flexible roads constructions, bitumen plays an important role of thebinding the aggregated by coating over the aggregates. It helps in improving the road strengththrough its water resistance is very poor. The common method that can be used to improve thequality of the bitumen is through modifying it through blending it with organic and syntheticpolymers like plastics and rubbers.Polymer modified bitumen is emerging as the important construction material for the roads andhave advantages like being a pollution menace and this process help solve the pollution becausemost of the plastic wastes are polymers. Extensive research is being done in recent decades onusage of polymers in road construction due to ever-increasing traffic conditions and failure ofconventional road materials due to high traffic density and in extreme weather conditionsPolymers can be directly mixed with the existing materials present at the site during the roadconstruction to stabilize these roads. These polymers can also be used to improve the propertiesof bitumen or aggregates used in asphalt road construction1.1 Background research about types of polymers used in road constructionElastomers is one of the most common polymers used in asphalt road products around the worldMost common elastomers include synthetic thermoplastic rubber polymers, such as SBS, styrenebutadiene rubber (SBR), styrene ethylene butadiene styrene (SEBS) and polybutadiene rubber(PB).Reclaimed tyre rubber is used to improve deformation resistanceSulphur and thermoplastic polymers are used to the workability and deformationresistance of the asphaltThermoplastic elastomers improve setting systems fatigue characteristics overall healthand resistance of the product1.2 Background study on BitumenPolymers can be used to improve the properties of bitumen, aggregates and to strengthen thesubsurface layers of the roadsFor this research, we are going to look at polymer usage in bitumen modificationBitumen is a by-product of petroleum. It is mainly used as the binder for aggregates in roadconstruction because it is durable and is hoped. It is a soft and thermoplastic material and theviscosity is directly proportional to the temperature. It is available almost throughout the worldand is economicalUse of bitumen for various purposes dates to ancient civilizations and is also described as"mankind's oldest engineering material" but increase in usage and production of the commercial
The Use of Polymers in Road Construction4was not found until the early 19thcentury. Demand for bitumen increased drastically due to theproduction of motorized vehicles.Today bitumen is used almost for all the major road constructions around the world.Urbanization, demand, Rapid development and the ever-increasing traffic conditions lead failureof bitumen in many aspects. This paved the way for bitumen modification,In consideration ofincreased traffic loads and in order to improve pavement performance, polymer-modifiedasphalts (PMA) have been developed during the last few decade[ CITATION Hie17 \l 1033 ]2.0 Types of polymers2.1 Thermoplastic elastomersStyrene–butadiene–styrene (SBS)Styrene–butadiene–rubber (SBR)Styrene–isoprene–styrene (SIS)Styrene–ethylene–butadiene–styrene (SEBS)Ethylene–propylene–diene terpolymer (EPDM)Isobutene–isoprene copolymer (IIR)Natural rubberCrumb tyre rubberPolybutadiene (PBD)Polyisoprene2.2 Thermoplastic polymersEthylene vinyl acetate (EVA)Ethylene methyl acrylate (EMA)Ethylene butyl acrylate (EBA)Atactic polypropylene (APP)Polyethylene (PE)Polypropylene (PP)Polyvinyl chloride (PVC)Polystyrene (PS)2.3 Thermosetting polymersEpoxy resinPolyurethane resinAcrylic resinPhenolic resinSome of the properties improved by using the above additives in bitumen mixes areSetting timeDurabilityElasticityFatigue
The Use of Polymers in Road Construction5Resistance to deformation etcPolymer coated aggregate (PCA) is also another type of polymer used in road construction wherethe aggregates are coated with polymers to increase their binding property.
The Use of Polymers in Road Construction63.0 Literature review:The two main types of polymers used in bitumen modification are plastometers andthermoplastic plastometers. During the last 40 years, more and more researchers began toconcentrate on polymer modification of bitumen and a rapidly increasing number of researcharticles have been published since the 1970s. In these, the various investigated polymersincluded elastomers (e.g. polyethylene (PE), polypropylene (PP), ethylene–vinyl acetate (EVA),ethylene–butyl acrylate (EBA)) and thermoplastic elastomers (e.g. styrene–butadiene–styrene(SBS), styrene–isoprene–styrene (SIS), and styrene–ethylene/butylene–styrene (SEBS))These Polymers were reported to lead to some improved properties of bitumen, such as higherstiffness at high temperatures, higher cracking resistance at low temperatures, better moistureresistance or longer fatigue life[ CITATION Leo16 \l 1033 ]Along with the advantages of Polymer modified bitumen researchers also found manydisadvantages and drawbacks in using polymers for bitumen modification including high cost,some PMBs' high-temperature sensitivity, low ageing resistance, poor storage stability and thelimited improvement in elasticity. In this, the combination of bitumen oxidation and polymerdegradation was reported to cause polymer modified bitumen's ageing propensity[ CITATIONGün12 \l 1033 ]which seems especially challenging for some unsaturated polymers, e.g. SBS.Other defects such as poor storage stability, the effect of chemical structure and reactivity ofpolymers on compatibility with bitumen, were also discovered.Et Burak Sengoz published in his paper about Construction and Building materials on September2008. In his has, he presented a laboratory study about the modified bitumen when mixed withStyrene butadiene styrene (SBS) and ethylene vinyl acetate (EVA). A 50/70 proportion ofbitumen was mixed with SBS and EVA. Also, the mechanical properties were studied about thehot-mix asphalt (HMA) including the base bitumen. The results showed that the properties ofmodified bitumen's and also the mechanical properties change as per the type of polymer and itscontent. When the proportion of polymer was low, the sample showed the existence of dispersedpolymer particles in a continuous bitumen phase. Whereas, at higher proportions of the polymera continuous phase polymer phase was observed. The paper concluded saying that the use ofSBS and EVA in the bitumen improves the properties of the bitumen such as; penetration,softening point, temperature susceptibility, etc. It was also concluded that the mechanicalproperties of HMA prepared with the SBS PMB samples such as Marshall Stability wereenhanced with the increasing polymer contents[ CITATION Rob10 \l 1033 ]3.1Thermoplastic elastomersIs referred to thermoplastic rubbers and is a class of copolymers where rubber mix physicallywith plastic and consist of materials both elastomeric and thermoplastic properties.Thermoplastic is easily used in injection moulding and show benefits of both material soft plasticand rubber. The benefit of using thermoplastic elastomers is its stretching ability to moderate
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