Rubber/crete: Mechanical properties of scrap to reuse tire-derived rubber in concrete; A review

Abstract

The recycling of waste tires is of paramount importance for environmental protection and for economic reasons. The number of scrapped tires in the United States has reached 550 million per year and is still rising. Even higher numbers are estimated in the European Union, reaching 1 billion tires per year. Disused tires create waste with a highly negative environmental impact. Tire disposal mainly involves highly polluting treatments (e.g. combustion processes to produce fuel oil), with only a small percentage of waste (3% to 15%) destined for less-invasive treatments such as powdering. In this article we will look at previous studies in which different amounts of waste tire powder are combined with cement concrete mixtures to provide a final product with mechanical properties suitable for engineering applications. Previous work has shown that a good compressive strength can be achieved through replacing 30% of powdered tire with crushed sand. First, as the percentage of aggregation between crumb rubber and crushed sand increases, compressive strength decreases. Second, aggregation replacement of crumb rubber and crushed sand shows a reduction in density at around 10%. Third, the modulus of elasticity depends on the percentages added: the more rubber added to concrete, the less elastic the product will be. In addition, a less tough concrete means higher strength. However, adding rubber to concrete increases the toughness.1

Multi-Physics Analysis for Rubber-Cement Applications in Building and Architectural Fields: A Preliminary Analysis

“…As a promising solution to the tire disposal problem, the strategy based on the incorporation of rubber particles (produced by shredding and commutating used tires) in cementitious matrices has gained considerable attraction from many researchers working in the civil engineering and building sectors [3][4][5]. According to the previous works, the physical and viscoelastic properties of the recycled tire rubber aggregates confer to concrete material interesting engineering properties: Elasticity, lightweight, vibration damping, durability, sound, and thermal insulation [6,7]. However, the mechanical strength of rubberized material decreases significantly as the rubber content increase.…”

Crumb Rubber as a Secondary Raw Material from Waste Rubber: A Short Review of End-Of-Life Mechanical Processing Methods

“…The addition of crumb rubber to the cement compositions leads to compressive strength decrease. In the work by [56], the polymer reinforcement was used as a substitute for some of the mineral components used in traditional concrete. The development of three-dimensional (3D) printing for the production of building structures and entire buildings has led to the creation of building 3D printable cement-based mix with the addition of crumb rubber, suitable for construction [57].…”

Extrusion-Based Additive Manufacturing of Concrete Products: Revolutionizing and Remodeling the Construction Industry

“…Guowei Ma proposed a printable cement mixture optimized with the addition of a certain percentage of copper tailings to replace the sand to improve the mechanical performance of concrete [33]. Besides, another possibility is working on the addition of fillers as crumb rubber, due to the fact of its advantages on toughness resistance, insulation, water absorption, and excellent machine performance (printing performances related to the quality of aggregation) [34]. Several academic and industrial research teams based their work on the development of low-environmental printable cement materials, as geopolymer mortars, for both small-scale [13,35] and large-scale applications [36].…”

“…"Green cement materials" are characterized by application of industrial wastes to reduce consumption of natural resources and energy and pollution of the environment [55]. Fillers, deriving from industrial waste (tire rubber [34], textile waste [56], paper pulp [57]), can be added in partial replacement of the aggregates to optimize several physical properties of the mixture such as density, thermal insulation, sound insulation, and damping of the mechanical vibrations. However, this strategy will require thorough studies related to the printing of the mixture, certification of structural performances, and optimization of the cement matrix-filler interface.…”