Mário Garrido

University of Lisbon | UL · Civil Engineering Research and Innovation for Sustainability (CERIS)

The construction sector is one of the largest creators and distributors of wealth, contributing to economic growth worldwide. However, this economic growth comes together with very high environmental impacts. Thus, rehabilitation solutions that can adapt the current building stock to today’s structural requirements are needed, increasing structural...

This paper investigates the durability of 8 mm thick pultruded glass fibre-reinforced polymer (GFRP) composite laminates manufactured with either unsaturated polyester or vinyl ester resins. Over a period of 12 months, a comprehensive set of experiments was carried out to assess the durability performance of these GFRP laminates under accelerated l...

This paper presents an experimental study of the wet freeze–thaw (FT) durability of a fibre–polymer composite produced by vacuum infusion using an innovative bio-based unsaturated polyester resin (UPR) and basalt fibres. As the benchmark, an equivalent composite produced with a conventional (oil-based) UPR was also tested. The composites were preco...

Bio-based resins, obtained from renewable raw materials, are a more sustainable alternative to oil-based resins for fiber-reinforced polymer (FRP) composites. The incorporation of lignin in those resins has the potential to enhance their performance. This paper presents results of an experimental study about the effects of Lignoboost lignin incorpo...

This paper presents an experimental study about the use of innovative bio-based pultruded carbon-fiber-reinforced polymer (CFRP) laminates for structural strengthening. The bio-based laminates were produced in the framework of an applied research project (BioLam) using a resin system with 50% (wt.%) bio-based content, obtained from renewable resour...

This paper presents an overview of an on-going research project that aims at the development of bio-based pultruded carbon fibre reinforced polymer (CFRP) laminates for strengthening of reinforced concrete (RC) structures. The bio-based laminates were developed using a resin system that is partially derived from renewable resources, with a bio-base...

This paper presents the development and industrial manufacturing of a pultruded high-performance carbon fibre (CF) reinforced polymer (CFRP) composite strip using a bio-based unsaturated polyester (UP) resin containing more than 50% of its weight derived from renewable raw materials. The bio-based CF/UP strengthening strip, comprising unidirectiona...

This paper presents the manufacturing and the mechanical and thermomechanical properties of a bio-based glass fibre-reinforced polymer (GFRP) composite, produced by vacuum infusion, using an in-house high-performance bio-based unsaturated polyester resin (UPR) with more than 50 wt.% of its content derived from renewable raw materials. Specimens wer...

Research on biobased thermoset resins has been overlooked when compared with the rapid progress on biobased thermoplastics. The objective of this work was to develop unsaturated polyester prepolymers based on building blocks derived from renewable raw materials, namely, biobased isosorbide, 1,3‐propanediol, and fumaric acid, with petroleum‐derived...

This paper presents long-term prediction models for the mechanical property retention of pultruded GFRP materials, with either isophthalic unsaturated polyester or vinyl ester resin, derived from a set of experimental results gathered over a period of two years of accelerated ageing under hygrothermal exposure. The prediction models were fitted to...

The long-term performance of glass fibre reinforced polymer (glass-FRP, GFRP) materials used in civil engineering applications is influenced by several factors, such as their constituent materials, their production processes and quality level, and environmental factors, such as temperature, moisture, or ultra-violet radiation, among others. In the...

One of the main concerns about the use of fibre reinforced polymer (FRP) materials in civil engineering structural applications is the potential reduction of their stiffness- and strength-related properties when exposed to elevated temperature. The first part of this paper presents an assessment of existing design guidelines for FRP structures, reg...

Research concerning the long-term behaviour of fibre reinforced polymer (FRP) composites in civil engineering applications is increasing, as key actors in this industry recognize the existence of many knowledge “gaps” that still need to be fulfilled. Several competing mechanisms may affect the durability of FRPs during exposure to hygrothermal agei...

This paper presents an experimental investigation about the effect of elevated temperature on the mechanical properties of two polyurethane (PUR) foams, with densities of 40 kg/m ³ and 93 kg/m ³ . The experimental campaign included shear and compressive tests over a temperature range of 20°C–200°C, performed to assess the degradation of the mechani...

This paper presents an experimental study about the fire resistance behaviour of composite sandwich floor panels made of glass-fibre reinforced polymer (GFRP) faces and polyurethane foam core subjected to a standard fire scenario and a mechanical load. Three full-scale sandwich specimens were tested: an unprotected specimen and two specimens protec...

The durability of pultruded GFRP composites is critical to their performance in civil engineering applications, for which comprehensive and validated data is limited. To address this issue, this study presents an extensive experimental programme on the effects of hygrothermal ageing on the performance of pultruded GFRP profiles made of two alternat...

The aim of this study is to quantify and compare the environmental impact from cradle-to-gate of different systems for building floor rehabilitation. The Life Cycle Assessment (LCA) method was used for the evaluation of the potential environmental impact of the production of each floor system in eight categories and a monetisation method was used f...

Composite sandwich panels have been increasingly considered in structural applications due to their lightweight, high strength, environmental resistance, and ease of assembly. Yet, since transmission loss phenomena are usually governed by mass, their low weight renders composite sandwich panels potentially inefficient in terms of acoustic performan...

Plasticized poly vinyl chloride (PVC) membranes are widely used for waterproofing in civil engineering works. Such membranes are susceptible to environmental degradation and accidental damage, and may thus require localized repairs throughout their service life. These operations typically involve covering the damaged areas with new PVC membranes, p...

Balsa wood is increasingly considered as a core material in sandwich panels for applications in several industries. However, there is still very limited information about its mechanical behaviour at elevated temperature. This article presents an experimental and analytical study about the effects of elevated temperature on the shear behaviour of en...

Composite sandwich panels are being increasingly considered for civil engineering structural applications, offering high versatility in constituent materials and their geometrical arrangement. This translates to a high number of design variables, in addition to a potentially large number of design requirements and objectives related to the panels’...

Sandwich structures comprising glass-fibre reinforced polymer faces and low-density core constitute an efficient and versatile constructive system for civil and ocean engineering structures. However, being multilayered with relatively soft core materials, they are particularly susceptible to damage under concentrated loads. Whilst numerous studies...

This paper presents some numerical investigations related to the use of a new approximation function to be applied in Carrera's Unified Formulation (CUF). The main objective is to study and assess the efficiency of the CUF, when Legendre approximation functions are used at the section level, on 1D element, using an equivalent single layer (ESL) for...

This paper presents experimental and analytical investigations on the creep response of full-scale laminated glass panels. The experimental study comprised relatively long-term (350-h) flexural creep tests on full-scale 3-layer Polyvinyl butyral (PVB)-laminated and 4-layer SentryGlas (SG)-laminated glass panels. The experimental data were fit using...

This paper presents an experimental investigation on the performance of different techniques for executing joints between aged and new bituminous membranes in order to evaluate the performance of waterproofing repair systems. Three different types of fibre reinforced membranes were considered: (i) oxidised bitumen membranes, (ii) APP-modified bitum...

Sandwich panels often need to be designed to sustain significant permanent loads, raising the need to accurately account for long-term creep deformation. However, the accurate prediction of creep in sandwich panels is not trivial, particularly owing to their composite multi-layered nature, the multitude of possible face and core material combinatio...

This paper presents an experimental and analytical study about the effect of temperature on the shear creep response of a rigid polyurethane (PUR) foam within the scope of sandwich panel application in building floors. Shear creep tests were carried out on a foam (87.4 kg/m3) subjected to shear stress levels of 11%, 22% and 44% of its shear strengt...

Composite sandwich panels with reinforcement ribs or webs are being increasingly considered for structural applications in civil engineering. Such panels are prone to creep when subjected to significant permanent loads and therefore the effects of this phenomenon must be duly accounted for in their design. Data regarding the viscoelasticity of sand...

This paper presents experimental and analytical investigations about the elastic and viscoelastic (creep) behaviour of sandwich panels made of glass-fibre reinforced polymer faces and a polyethylene terephthalate foam core, produced by vacuum infusion for civil engineering structural applications. First, the elastic response of the panels’ constitu...

This paper presents an experimental and analytical study about the effect of temperature on the flexural creep of GFRP laminates produced by vacuum infusion. Such laminates are considered for use in the faces of sandwich panels for building floor application. Flexural creep tests were carried out in a three point bending configuration for stress le...

The use of advanced composites for building rehabilitation presents several advantages when compared with traditional construction materials. When degraded building floors need to be replaced, composite sandwich panels are a potentially interesting solution, namely for buildings with load-bearing rubble masonry walls. In this paper, connection syst...

A connection system between adjacent sandwich panels for use in building floor rehabilitation, consisting of an adhesively (epoxy) bonded Z-joint, is proposed and studied. Experimental and numerical investigations were carried out to assess the joints' behaviour under vertical loads, their effect on the overall mechanical response of the sandwich f...

Palavras-Chave: Painéis sanduíche, espuma de poliuretano, fluência, temperatura, testes. Resumo. Este artigo apresenta um estudo sobre a fluência em corte de espumas rígidas de poliuretano (PUR), em particular, sobre a influência da temperatura na resposta viscoelástica. Foram realizados ensaios de fluência em corte em provetes de PUR sujeitos a di...

This paper presents experimental and analytical investigations about the creep behaviour of sandwich panels comprising glass-fibre reinforced polymer faces and rigid polyurethane foam core for civil engineering applications. A full-scale sandwich panel was tested in bending for a period of 3600 h, in a simply supported configuration, subjected to a...

For civil engineering structural applications, the viscoelasticity of polymeric materials must be adequately considered during design in order to guarantee that the associated long term deformations are compatible with functional and structural safety requirements. This paper presents a study about the viscoelastic behaviour of structural sandwich...

Purpose – The purpose of this paper is to present experimental investigations on the structural behaviour of composite sandwich panels for civil engineering applications. The performance of two different core materials – rigid plastic polyurethane (PU) foam and polypropylene (PP) honeycomb – combined with glass fibre reinforced polymer (GFRP) skins...

The financial resources available for infrastructure maintenance and rehabilitation are always limited, creating a need for efficient resource management and for the ability to predict maintenance actions throughout the infrastructure service period. In the context of bridge management, management systems have been developed and are already impleme...

In building management there is a need for selective and updated information regarding the condition of building components, in order for the decision processes to take place adequately. This assessment is essential in planning maintenance or repair actions that may be required, either in a curative form or in a preventive attitude. The aim of this...