Recovery of cotton fibers from waste Blue-Jeans and its use in polyester concrete

Se estudia el efecto de agregar fibras de algodón, provenientes de pantalones de mezclilla de desecho, en concreto polimérico elaborado con resina poliéster.Currently, the consumer tendency causes that the garments are dismissed more quickly, which generate increment of textile waste, such as Blue-Jeans. In this work, polyester concrete with waste cotton fibers was elaborated, and a novel treatment by gamma irradiation was carried out. The results show up to 40% improvement on the compressive strength, as well as 7% on the flexural strength. Additional improvements for irradiated concrete were obtained, when 300 kGy of irradiation dose was applied. Modifications on the surface, chemical structural and crystallinity of irradiated waste cotton fibers, were related with improvements on the mechanical properties of concrete

Mechanical characterization of fiber reinforced Polymer Concrete

A comparative study between epoxy Polymer Concrete plain, reinforced with carbon and glass fibers and commercial concrete mixes was made. The fibers are 6 mm long and the fiber content was 2% and 1%, respectively, in mass. Compressive tests were performed at room temperature and load vs. displacement curves were plotted up to failure. The carbon and glass fibers reinforcement were randomly dispersed into the matrix of polymer concrete. An increase in compressive properties was observed as function of reinforcement. The comparison also showed that Polymer Concrete, plain and reinforced, has a better performance than regular market concrete, suggesting that PC is a reliable alternative for construction industry

Fracture mechanics of polymer concrete

Dissertação apresentada para obtenção do grau de Doutor, na Faculdade de Engenharia da Universidade do Porto, sob a orientação do Prof. Joaquim Mendes Ferreir

Effect of temperature on the mechanical properties of polymer mortars

This paper presents the results of an experimental program to investigate the effect of temperature on the performance of epoxy and unsaturated polyester polymer mortars (PM). PM is a composite material in which polymeric materials are used to bond the aggregates in a fashion similar to that used in the preparation of Portland cement concrete. For this purpose, prismatic and cylindrical specimens were prepared for flexural and compressive tests, respectively, at different temperatures. Measurements of the temperature-dependent elastic modulus and the compressive and flexural strength were conducted using a thermostatic chamber attached to a universal test machine for a range of temperatures varying from room temperature to 90 ºC. The flexural and compressive strength decreases as temperature increases, especially after matrix HDT. Epoxy polymer mortars are more sensitive to temperature variation than unsaturated polyester ones

Fracture mechanics of polymer mortar made with recycled raw materials

The aim of this work is to show that industrial residues could be used in construction applications so that production costs as well as environmental protection can be improved. The fracture properties of polymer mortar manufactured with recycled materials are investigated to evaluate the materials behaviour to crack propagation. The residues used in this work were spent sand from foundry industry as aggregate, unsaturated polyester resin from polyethylene terephthalate (PET) as matrix and polyester textile fibres from garment industry, producing an unique composite material fully from recycled components with low cost. The substitution of fresh by used foundry sand and the insertions of textile fibres contribute to a less brittle behaviour of polymer mortar