Re-use assessment of thermoset composite wastes as aggregate and filler replacement for concrete-polymer composite materials: a case study regarding GFRP pultrusion wastes

Glass fibre-reinforced plastics (GFRP), nowadays commonly used in the construction, transportation and automobile sectors, have been considered inherently difficult to recycle due to both the cross-linked nature of thermoset resins, which cannot be remoulded, and the complex composition of the composite itself, which includes glass fibres, polymer matrix and different types of inorganic fillers. Hence, to date, most of the thermoset based GFRP waste is being incinerated or landfilled leading to negative environmental impacts and additional costs to producers and suppliers. With an increasing awareness of environmental matters and the subsequent desire to save resources, recycling would convert an expensive waste disposal into a profitable reusable material. In this study, the effect of the incorporation of mechanically recycled GFRP pultrusion wastes on flexural and compressive behaviour of polyester polymer mortars (PM) was assessed. For this purpose, different contents of GFRP recyclates (0%, 4%, 8% and 12%, w/w), with distinct size grades (coarse fibrous mixture and fine powdered mixture), were incorporated into polyester PM as sand aggregates and filler replacements. The effect of the incorporation of a silane coupling agent was also assessed. Experimental results revealed that GFRP waste filled polymer mortars show improved mechanical behaviour over unmodified polyester based mortars, thus indicating the feasibility of GFRP waste reuse as raw material in concrete-polymer composites.

Re-Use Assessment of Thermoset Composite Wastes as Aggregate and Filler Replacement for Concrete-Polymer Composite Materials: A case study regarding GFRP pultrusion wastes

Glass fibre-reinforced plastics (GFRP), nowadays commonly used in the construction, transportation and automobile sectors, have been considered inherently difficult to recycle due to both the cross-linked nature of thermoset resins, which cannot be remoulded, and the complex composition of the composite itself, which includes glass fibres, polymer matrix and different types of inorganic fillers. Hence, to date, most of the thermoset based GFRP waste is being incinerated or landfilled leading to negative environmental impacts and additional costs to producers and suppliers. With an increasing awareness of environmental matters and the subsequent desire to save resources, recycling would convert an expensive waste disposal into a profitable reusable material. In this study, the effect of the incorporation of mechanically recycled GFRP pultrusion wastes on flexural and compressive behaviour of polyester polymer mortars (PM) was assessed. For this purpose, different contents of GFRP recyclates (0%, 4%, 8% and 12%, w/w), with distinct size grades (coarse fibrous mixture and fine powdered mixture), were incorporated into polyester PM as sand aggregates and filler replacements. The effect of the incorporation of a silane coupling agent was also assessed. Experimental results revealed that GFRP waste filled polymer mortars show improved mechanical behaviour over unmodified polyester based mortars, thus indicating the feasibility of GFRP waste reuse as raw material in concrete-polymer composites.

Sistema de Gestão Técnica Aplicado aos Sistemas de Rega

A cidade do Porto é uma das regiões do país onde é importante uma gestão sustentável e integrada dos recursos hídricos. A (re) utilização de água surge neste contexto como uma possível resposta na sua utilização como um recurso hídrico passível de ser usado beneficamente, permitindo a poupança de fontes de água convencionais e aumentando a disponibilidade dos recursos hídricos existentes para finalidades que requerem padrões de qualidade mais exigentes. O potencial desta prática no nosso país é enorme, considerando que o volume de água tratada descarregada no ano 2000 era suficiente para suprir 10% das necessidades em água para rega num ano seco, sem necessidade de armazenamento sazonal. Por outro lado, um sistema de rega, quando devidamente projetado e funcionando adequadamente, permite que a água seja aplicada com um caudal, duração e frequência que maximizam o consumo da água e nutrientes pela planta. Este projeto consiste no desenvolvimento de um Sistema de Gestão Técnica para o controlo do sistema de rega dos jardins do ISEP – Instituto Politécnico de Engenharia do Porto com recurso a um autómato programável (PLC). Pretende-se otimizar os consumos energéticos do sistema de rega tendo em conta os parâmetros de humidade, temperatura e velocidade do vento característicos do local a regar. Outros dos objetivos é controlar o processo de enchimento e de rega. Esta operação consiste no controlo das bombas e respetivos débitos e conhecimento dos caudais necessários. Pretende-se, igualmente, definir e colocar em marcha todo o equipamento necessário para a realização do projeto. Os dados coletados devem ser tratados de tal modo que possam ser realizadas análises diárias, mensais e/ou anuais. Neste trabalho foram efetuados os cálculos de dimensionamentos relativamente às necessidades hídricas da planta e necessidades de rega, entre outros.