Recycled cellulose from Tetra Pak packaging as reinforcement of polyester based composites Gonzalo Martínez-Barrera a,⇑ , Miguel Martínez-López a,b , Nelly González-Rivas c , Juan Jose del Coz-Diaz b , Liliana Ávila-Córdoba d , João Marciano Laredo dos Reis e , Osman Gencel f a Laboratorio 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, Mexico b Department of Construction, University of Oviedo, 33204 Gijon, Spain c Centro Conjunto de Investigación en Química Sustentable UAEM-UNAM, Carretera Toluca-Atlacomulco km. 14.5, Unidad San Cayetano, Toluca, Estado de Mexico 50200, Mexico d Facultad de Ingeniería, Universidad Autónoma del Estado de México, Av. Universidad S/N, Cerro de Coatepec, Ciudad Universitaria, Toluca, Mexico e Theoretical and Applied Mechanics Laboratory – LMTA, Mechanical Engineering Post Graduate Program – PGMEC, Universidade Federal Fluminense – UFF, Rua Passo da Pátria,156 Bl. E sala 216, Niterói, RJ, Brazil f Civil Engineering Department, Faculty of Engineering, Bartin University, 74100 Bartin, Turkey highlights  Polymer concrete with waste cellulose from Tetra Pak packaging was elaborated.  The effects of gamma radiation on compressive and flexural properties were studied.  The highest mechanical performance is obtained with 2 wt% of waste cellulose from Tetra Pak.  The lower gamma dose provides the highest compressive strength.  Improvements on the compressive and flexural strength were obtained at irradiation dosages of 100 and 200 kGy. article info Article history: Received 17 April 2017 Received in revised form 21 September 2017 Accepted 26 September 2017 Keywords: Polymer concrete Recycling Cellulose Gamma radiation Mechanical properties abstract Addressing the environmental problems caused by waste generated by Tetra Pak packaging, in this work, polyester based composites with 80% of polyester resin and 20% of silica sand were elaborated; where the silica sand was partially replaced by recycled cellulose from waste Tetra Pak containers at concentrations of 1, 2, 4 and 6% by weight. Both recycled cellulose and composite specimens were subjected to ionizing radiation process by using gamma rays. The results show improvements on the mechanical properties (compressive and flexural strength as well as modulus of elasticity) of the composites when they are irra- diated at 100 and 200 kGy. Such improvements can be related with the structural modifications caused by gamma irradiation on the cellulose fibers, including changes in the morphology and the crystallinity; which were analyzed through to SEM, IR and XRD techniques. Ó 2017 Elsevier Ltd. All rights reserved. 1. Introduction Polyester based composites are the result from polymerization of the polyester resin mixed with a mineral aggregate. In this case, the polymerized monomer acts as binder for the mineral aggre- gates. Precast polyester composites have been used to produce a variety of products like acid tanks, manholes, drains, and highway median barriers. Special features of polyester composites can be an excellent bond agent between cement composite and steel struc- tures, as well as repairing material. Moreover, they show fast cur- ing, improved properties including compressive strength, specific stiffness, vibration damping, durability, as well as ability to form complex shapes, and resistance to chemicals and corrosion [1–4]. Few studies have been reported regarding the effect of fibers as reinforcement of polyester composites. Such fibers include steel, glass, carbon or polyester at different concentrations. Fiber rein- forced polymers (FRP) have numerous advantages, including excel- lent corrosion resistance, high fatigue resistance, low thermal expansion coefficient, and to have lightweight. Moreover, they https://doi.org/10.1016/j.conbuildmat.2017.09.181 0950-0618/Ó 2017 Elsevier Ltd. All rights reserved. ⇑ Corresponding author. E-mail address: gonzomartinez02@yahoo.com.mx (G. Martínez-Barrera). Construction and Building Materials 157 (2017) 1018–1023 Contents lists available at ScienceDirect Construction and Building Materials journal homepage: www.elsevier.com/locate/conbuildmat