Waste Tire Particles and Gamma Radiation as Modifiers of the Mechanical Properties of Concrete

Waste Tire Particles and Gamma Radiation as Modifiers of the Mechanical Properties of Concrete Eduardo Sadot Herrera-Sosa,1 Gonzalo Martínez-Barrera,2 Carlos Barrera-Díaz,3 and Epifanio Cruz-Zaragoza4 1Facultad de Química, Universidad Autónoma del Estado de México, Paseo Colón Esquina Paseo Tollocan s/n, 50180 Toluca, MEX, Mexico 2Laboratorio de Investigación y Desarrollo de Materiales Avanzados (LIDMA), Facultad de Química, Universidad Autónoma del Estado de México, km 12 de la Carretera Toluca-Atlacomulco, San Cayetano, 50200 Toluca, MEX, Mexico 3Centro Conjunto de Investigación en Química Sustentable, Universidad Autónoma del Estado de México, Universidad Nacional Autónoma de México (UAEM-UNAM), Carretera Toluca-Atlacomulco km 14.5, Unidad El Rosedal, 50200 Toluca, MEX, Mexico 4Unidad de Irradiación y Seguridad Radiológica, Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, A.P. 70-543, 04510 Mexico City, DF, Mexico Received 15 November 2013; Accepted 27 January 2014; Published 6 March 2014 Academic Editor: Osman Gencel Copyright © 2014 Eduardo Sadot Herrera-Sosa et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Abstract In polymer reinforced concrete, the Young’s modulus of both polymers and cement matrix is responsible for the detrimental properties of the concrete, including compressive and tensile strength, as well as stiffness. A novel methodology for solving such problems is based on use of ionizing radiation, which has proven to be a good tool for improvement on physical and chemical properties of several materials including polymers, ceramics, and composites. In this work, particles of 0.85 mm and 2.80 mm obtained from waste tire were submitted at 250 kGy of gamma radiation in order to modify their physicochemical properties and then used as reinforcement in Portland cement concrete for improving mechanical properties. The results show diminution on mechanical properties in both kinds of concrete without (or with) irradiated tire particles with respect to plain concrete. Nevertheless such diminutions (from 2 to 16%) are compensated with the use of high concentration of waste tire particles (30%), which ensures that the concrete will not significantly increase the cost. 1. Introduction The final disposal of used tires is a major environmental problem. In Mexico, it is estimated that only 10% of the 30 million disposed tires are recycled. The landfills where they are disposed represent a severe risk of fire and a health hazard due to the presence of noxious fauna such as rats, cockroaches, flies, and mosquitoes which can be infectious [1, 2]. The most common method to dispose waste tires is to burn them for vapor, heat, or electricity [3, 4]. The usage of waste tires as alternative fuel in cement furnaces is generalized across the US and Europe [5]. However, these practices result in the generation of organic and inorganic compounds such as zinc oxide (ZnO) and zinc sulfide (ZnS), in hydrocarbon gas, aromatic volatile compounds, liquids formed by heavy and light oils, and all these byproducts which are highly polluting [6]. Another approach for the application of waste tires includes hot bituminous mixes as pneumatic dust for the agglutinative modification in asphalt pavements [7–9]. This application has been more or less effective, but not enough for reducing the reserves of waste tires, since these novel technologies are more expensive than conventional methods [10]. An alternative option is to use them as substitute of fine or coarse aggregate in concrete. Their characteristics can improve mechanical properties of concrete as strength and modulus of elasticity, instead of those achieved by sand or stone. Concrete is one of the most important materials in the construction industry around the world, not only for its cost, but also for its properties as well as its readiness for forming before it hardens which include resistance to climate and durability, among others. However, concrete has a great impact in the environment, it requires great amounts of natural resources for its production (sand, gravel, and water), and the cement generation produces large amounts of carbon dioxide which is discharged in the atmosphere. In fact, it is estimated that cement industry is responsible for the emission of one million tons of to the atmosphere [11]. In order to reduce the ecological impact, many efforts have been made for reducing the consumption of nonrenewable resources in the production of concrete; one of these is the production or addition of recycled materials into the mixture in substitution of the common aggregates, taking care of the final quality, that include parameters as resistance, modulus of elasticity, and durability, among others [12]. When adding particles to concrete formation, int (...truncated)