Miguel Martínez-López

Waste Cellulose from Tetra Pak Packages as Reinforcement of Cement Concrete

The development of the packaging industry has promoted indiscriminately the use of disposable packing as Tetra Pak, which after a very short useful life turns into garbage, helping to spoil the environment. One of the known processes that can be used for achievement of the compatibility between waste materials and the environment is the gamma radiation, which had proved to be a good tool for modification of physicochemical properties of materials. The aim of this work is to study the effects of waste cellulose from Tetra Pak packing and gamma radiation on the mechanical properties of cement concrete. Concrete specimens were elaborated with waste cellulose at concentrations of 3, 5, and 7 wt% and irradiated at 200, 250, and 300 kGy of gamma dose. The results show highest improvement on the mechanical properties for concrete with 3 wt% of waste cellulose and irradiated at 300 kGy; such improvements were related with the surface morphology of fracture zones of cement concrete observed by SEM microscopy.

Polypropylene Fibre Reinforced Polymer Concrete: Effect of Gamma Irradiation

Design of polymer concrete involves extensive studies on their materials in order to get improved properties; specifically on the physicochemical properties of both polymer resin and mineral aggregates, including size and shape of the last one. Alternative studies are focusing on using different materials or methods to obtain such improvements. In this work, polymer concrete was elaborated with unsaturated polyester resin, marble particles and polypropylene fibres, after it was modified by using gamma radiation to achieve a complete polymerization. The results show improvements in the compressive strength and in the modulus of elasticity with 0.2 vol.% of polypropylene fibres and irradiation at a dose of 250 KGy. However, lower compressive strains were obtained when using gamma radiation.

Waste Materials from Tetra Pak Packages as Reinforcement of Polymer Concrete

Different concentrations (from 1 to 6 wt%) and sizes (0.85, 1.40, and 2.36 mm) of waste Tetra Pak particles replaced partially silica sand in polymer concrete. As is well known, Tetra Pak packages are made up of three raw materials: cellulose (75%), low density polyethylene (20%), and aluminum (5%). The polymer concrete specimens were elaborated with unsaturated polyester resin (20%) and silica sand (80%) and irradiated by using gamma rays at 100 and 200 kGy. The obtained results have shown that compressive and flexural strength and modulus of elasticity decrease gradually, when either Tetra Pak particle concentration or particle size is increased, as regularly occurs in composite materials. Nevertheless, improvements of 14% on both compressive strength and flexural strength as well as 5% for modulus of elasticity were obtained when polymer concrete is irradiated.

Concreto Polimérico Reforzado con Fibras de Luffa

Resumen Se elaboro un tipo de concreto polimerico anadiendo fibras de luffa con el fin de mejorar el la resistencia a la compresion y a la flexion, asi como el grado de elasticidad. Se prepararon probetas de concreto polimerico con 30% en volumen de resina poliester y el 70% restante con arena silice y diversas concentraciones de fibras de luffa (0.3, 0.6 y 0.9% en volumen), asi como pobretas testigo sin fibra. Las probetas testigo, sin fibra, fueron sometidas a radiacion gamma. La evaluacion de la resistencia mecanica a la compresion y a la flexion de las probetas de concreto polimerico se realizo en una maquina universal de pruebas mientras que el modulo de elasticidad dinamico se determino con un equipo de ultrasonido. Una vez efectuado las pruebas mecanicas a los concretos, se analizaron regiones de las fibras de luffa en un microscopio electronico de barrido. Los resultados muestran disminucion en los valores de la resistencia a compresion y la flexion y la elasticidad para las probetas con fibras. Las propiedades mejoraron para las probetas irradiadas.

Polymer concrete reinforced with recycled-tire fibers: Mechanical properties

Polymer Concrete was reinforced with recycled-tire fibers in order to improve the compressive and flexural strength. Polymer concrete specimens were prepared with 70% of silicious sand, 30% of polyester resin and various fiber concentrations (0.3, 0.6, 0.9 and 1.2 vol%). The results show increment of 50% in average of the compressive and flexural strength as well as on the deformation when adding 1.2 vol% of recycled-fibers.

Effect of the Loofah-fibers on the mechanical properties of Polymer Concrete

Polymer Concrete was reinforced with Loofah fibers in order to improve the compressive and flexural strength. Polymer concrete specimens were prepared with 70% of silicious sand, 30% of polyester resin and various fiber concentrations (0.3, 0.6 and 0.9 vol%). The results show decrease in the values of mechanical properties including flexural strength, compressive strength and compression modulus of elasticity.