Effect of plastic aggregates addition on accelerated carbonation of sand concrete

Abstract

PurposeThis study aims to the framework of the development of a new sand concrete, essentially manufactured with river/dune sand and recycled plastic aggregates (PAs; 0/3.15 mm). This new concrete may have a great interest, as it can enable us to achieve the best economical, technical and ecological solutions for local construction problems. Given the high abundance of dune sand (DS) and the large quantities of plastic waste, plastic–mineral sand concrete can be a good alternative to the ordinary building materials available on the local market.Design/methodology/approachA replacement of sand by PAs is made by volume substitution. The plastic percentages laid down are 0%, 25%, 50% and 100%. Indeed, after a general experimental characterization of the studied composites, the investigation mainly concentrated on the study of the effect of the addition of plastic particles on the accelerated carbonation of river sand (RS) concrete and DS concrete, separately.FindingsThe density of the composites and consequently their compressive strength are slightly reduced; but their thermal insulation is significantly improved. Their structure seems to be homogeneous, the plastic grains are well distributed in the matrix and the adhesion “plastic–matrix” is good. At small plastic contents, the RS concrete is slightly better. As regards the carbonation results, the PAs significantly contribute to the improvement of the resistance of the composite against carbonation effect. It can be observed that increasing the proportion of plastic particles in sand concrete considerably decreases the thickness of the carbonated concrete.Originality/valueThe studies led on the behavior of plastic concrete, particularly in arid zones, are very limited. Moreover, for sand concrete, there are no similar studies. Therefore, the characterization of such materials is necessary. In addition of thermo-mechanical characterization, this work aims at studying the durability of the material, especially its resistance to carbonation. On the other hand, this work has a significant positive impact on both environment and economy, since it focuses on the recycling of industrial waste, and the valorization of DS, which is available in great quantities in south of Algeria.