Sanya, Emile AdjibadéKowanou, HouénouTchéhouali, Dèfodji Adolphe2016-07-202016-07-202015Sanya, E. A., Kowanou, H., & Tchéhouali, D. A. (2015). Valorisation of waste plastic bags in cement-mortar composites as coating of local sand aggregates: Physicomechanical characterisation and potential uses. Acta Structilia, 22(2), 45-80.1023-0564 (print)2415-0487 (online)http://hdl.handle.net/11660/3502English: Increasingly high quantities of waste plastics cause major environmental problems in Benin due both to the non-biodegradability of such by-products of the petroleum industry and to a lack of appropriate means of treatment. An option to valorise waste plastic bags is to use these in construction processes. This article studies the incorporation of waste plastic bags into cement-mortar with the aim of reducing proliferation. It explores the immediate consequences of cement-mortar-plastic combinations, such as changes in the resultant composite’s water absorption ratio and mechanical properties. The process of making the composite includes some main steps, during which waste plastic bags are first melted at 200°C-250°C and then mixed with sand aggregates. These coated aggregates are then mixed with cement and water into mortar. Moulded specimens of derived composites are then submitted to hydrothermal ripening and mechanical analysis. Experimental results allow optimizing the sand-aggregates coating process, providing data to locate the most appropriate ratio of plastic bags to be between 8% and 12% (wt/wt.mix):theoretically10.07%. The adopted practical value was 10%, leading to cement-plastic-mortar compositeswith90%reduction of water absorption ratio and 11.60% decrease in absolute density, compared to uncoated sand composites. Similarly, the mechanical strengths of composites were 8.83±0.34MPa in compression and 4.1±0.82MPa in 3-points flexural bending, corresponding to 74.1% and 48.1% weakening, respectively. These resistances were judged to be weak, with the result that the composites thus obtained cannot be used as the main elements of structural constructions. Potential applications are water-sealing/repellent materials in walls/soil, ending with good values of a wear-resistance index similar to commercial quarry tiles/stoneware.Afrikaans: Hoë hoeveelhede afvalplastiek veroorsaak toenemend groot probleme in die omgewing van Benin as gevolg van beide die nie-afbreekbaarheid van sodanige by-produkte van die petroleum-industrie asook ‘n gebrek aan ‘n geskikte middel om dit te behandel. ‘n Opsie om afvalplastieksakke te valoriseer is om dit in konstruksieprosesse te gebruik.Hierdie artikel ondersoek die invoeging van afvalplastieksakke in sement-klei met die doel om die verspreiding daarvan te verminder.Dit ondersoek die onmiddellike gevolge van sement-klei-plastiek kombinasies, soos veranderinge in waterabsorpsieverhouding, asook die gevolglike saamgestelde en meganiese eienskappe daarvan.Die proses om die samestellings te maak behels ‘n paar belangrikste stappe, waartydens afvalplastieksakke eerstens gesmelt word by 200 °C - 250 °C en dan gemeng word met sand-aggregate.Hierdie bedekte aggregate word dan gemeng met sement en water tot ‘n klei.Gevormde monsters van afgeleide samestellings word dan voorgelê vir hidrotermale rypwording en meganiese analise.Eksperimentele resultate laat optimalisering van die sandaggregate bedekkingsproses toe, deur data te verskaf om die mees geskikte verhouding van plastieksakke op te spoor wat tussen 8% en 12% (wt / wt.mix): 10.07% teoreties behoort te wees.Die aanvaarde praktiese waarde was 10%, wat gelei het tot sement-plastiek-klei samestellings met 90% vermindering van waterabsorpsie-verhouding en 11,60% afname in absolute digtheid, in vergelyking met onbedekte sand samestellings.Net so, was die meganiese sterkte van die samestellings 8,83 ± 0,34 MPa in kompressie en 4,1 ± 0,82 MPa in 3-punte buig buiging, wat ooreenstem met 74,1% en 48,1% verswakking, onderskeidelik.Hierdie weerstand is swak, met die gevolg dat die samestellings nie gebruik kan word as die belangrikste elemente van strukturele konstruksies nie.Potensiële toepassings daarvan is water-verseëling/afweermiddel materiaal in mure/grond, met goeie waardes van ‘n dra-weerstand indeks soortgelyk aan kommersiële kleiteëls steenware.enWaste plastic bagsCement-plastic-mortar compositeAggregates coatingRipeningWater-absorption ratioWater-resistance indexArticleUniversity of the Free State