José Dinis Silvestre

Inspection and Diagnosis of Gypsum Plasterboard Walls

This paper proposes an expert system to support the inspection and diagnosis of partition walls or wall coverings mounted using the drywall (DW) construction method. This tool allows the succinct characterization of the pathological situation of each DW inspected. It also eases the systematization of the inspections included in periodic maintenance actions, thereby preventing future defects. The proposed tool includes a classification of defects in DW and their probable causes. The correlation matrices between defects and between defects and probable causes complement these classifications. Finally, the diagnosis methods and the repair techniques suitable for each DW defect are classified. All the defects, diagnosis methods, and repair techniques have individual files containing their significant information. The proposed classifications were validated via standard inspections of DW in three shopping centers, four stores, a school, three offices, a gymnasium, two condominiums, a hospital, four hotels, and two restaurants.

Review on concrete nanotechnology

The study of the application of nanotechnology in the construction industry and building structures is one of the most prominent priorities of the research community. The outstanding chemical and physical properties of nanomaterials enable several applications ranging from structural reinforcement to environmental pollution remediation and production of self-cleaning materials. It is known that concrete is the leading material in structural applications, where stiffness, strength and cost play a key role in the high attributes of concrete. This paper reviews the literature on the application of nanotechnology in the construction industry, more particularly in concrete production. The paper first presents general information and definitions of nanotechnology. Then, it focuses on the most effective nanoadditives that readily improve concrete properties, such as (i) nanosilica and silica fume, (ii) nanotitanium dioxide, (iii) iron oxide, (iv) chromium oxide, (v) nanoclay, (vi) CaCO3, (vii) Al2O3, (viii) carbon nanotubes and (ix) graphene oxide. Besides summarising the main nanomaterials used in concrete production as well as the results achieved with each addition, some future potential consequences of nanotechnology development and orientations to explore in construction are discussed.

NativeLCA - a systematic approach for the selection of environmental datasets as generic data: application to construction products in a national context

PurposeThe aim of this paper is to propose guidelines for the selection of an accurate life cycle assessment (LCA) dataset of building products to be used as generic data for a national context.MethodsThe guidelines are structured within a methodology, called NativeLCA. First, a review of available datasets for construction products is presented such as generic LCA and Environmental Product Declaration (EPD) databases for both national (e.g. France, Germany, Spain etc.) and European context. Secondly, a method is proposed to choose appropriate generic datasets by means of a hybrid methodology. A meta-analysis is conducted in the first step on the sample of collected datasets from the literature. When relevant, product-specific data (EPD of the different producers) are averaged to represent an average data or existing generic data are adapted to be more suitable for the context. Then, a data quality assessment enables to rank the different datasets according to the goal and scope of the study.Results and discussionThis study provides consistent guidelines that can be used by building LCA practitioners to select relevant datasets depending on their goal and scope. A full case study for stone wool boards illustrates and demonstrates the applicability and usefulness of the proposed methodology, namely in the selection of a coherent dataset as generic data for a national context. This work highlights the issues in terms of choice and adaptation of existing data for a national context. Industry data cannot be adapted due to confidentiality issues unlike unit process generic data. The use of data quality indicators then helps to select the relevant generic data for each context according to user needs.ConclusionsWhile further efforts are needed to develop regional and sector-specific LCA databases adapted for each national context, the proposed guidelines showed that the current use or adaptation of existing data, if consistently done, can lead practitioners to increase the reliability of building LCA studies according to their goal and scope definition.

Effect of Water on the Degradation of Gypsum Plaster Coatings: Inspection, Diagnosis, and Repair

AbstractThis paper presents an expert system designed to support the inspection and diagnosis of gypsum plaster coatings applied to partition walls and ceilings [interior gypsum plaster (IGP)]. It includes a classification of the defects that may affect IGP and their probable causes, the correlation matrices amongst defects and between defects and probable causes, and a classification of diagnostic methods and repair techniques suitable for each type of IGP defect. This inspection system was validated through standard IGP inspections undertaken on 119 walls or ceilings in 23 buildings located throughout Portugal. A statistical analysis of the results of the inspection is given that provides details on, in particular, the pathological problems related to the action of water on IGP because the presence of moisture within or on the surface of IGP coatings was shown to affect the severity of the problems of inspected samples. The characteristics and frequency of occurrence of dampness, biodeterioration, and e...

Environmental life cycle assessment of coarse natural and recycled aggregates for concrete

Purpose: To present a comparative life cycle assessment (LCA) of natural and recycled coarse aggregates used in concrete production. Methods: LCA was used to compare the environmental impacts of three alternative of procurement of coarse aggregates for concrete production: extraction and processing of natural aggregates; recycling of demolished concrete either using a fixed or a mobile plant. Site-specific data supplied by companies were used to model the life cycle of these aggregates. A sensitivity analysis was also made for the critical stages of these three life cycles. Results and conclusion: This paper presents and analyses innovative LCA data of production of coarse aggregates, both natural and recycled (from mobile or fixed recycling plants). The recycling process of aggregates has to be optimised, following a selective demolition of buildings that maximises waste recovery, reuse and recycling. The use of these aggregates in the production of concrete is more favourable than natural aggregates only in terms of land use and respiratory inorganics, but coarse recycled aggregates can present a better environmental performance than natural ones if fine recycled aggregates are also used in concrete production instead of being sent to a landfill. These results are, however, very sensitive to the transportation distances.

Inspection and Diagnosis System for Wood Flooring

AbstractThis paper presents an expert system to support the inspection and diagnosis of wood applied as a floor covering [wood flooring (WF)]. The defects that may affect WF along with their probable causes are classified in this system. The inspection system also embraces the correlation matrices between defects and between defects and probable causes, the classification of the diagnosis methods, and the repair techniques suitable for each WF defect. This paper also includes an example of an individual defect file containing a complete characterization and the most suitable diagnosis methods and repair techniques. This inspection system was validated through standard inspections of 90 WFs applied indoors and eight applied in exterior areas, in a total of 35 buildings.

Methodology for the Assessment of the Ecotoxicological Potential of Construction Materials

Innovation in construction materials (CM) implies changing their composition by incorporating raw materials, usually non-traditional ones, which confer the desired characteristics. However, this practice may have unknown risks. This paper discusses the ecotoxicological potential associated with raw and construction materials, and proposes and applies a methodology for the assessment of their ecotoxicological potential. This methodology is based on existing laws, such as Regulation (European Commission) No. 1907/2006 (REACH—Registration, Evaluation, Authorization and Restriction of Chemicals) and Regulation (European Commission) No. 1272/2008 (CLP—Classification, Labelling and Packaging). Its application and validation showed that raw material without clear evidence of ecotoxicological potential, but with some ability to release chemicals, can lead to the formulation of a CM with a slightly lower hazardousness in terms of chemical characterization despite a slightly higher ecotoxicological potential than the raw materials. The proposed methodology can be a useful tool for the development and manufacturing of products and the design choice of the most appropriate CM, aiming at the reduction of their environmental impact and contributing to construction sustainability.

An overview on the improvement of mechanical properties of ceramics nanocomposites

Due to their prominent properties (mechanical, stiffness, strength, thermal stability), ceramic composite materials (CMC) have been widely applied in automotive, industrial and aerospace engineering, as well as in biomedical and electronic devices. Because monolithic ceramics exhibit brittle behaviour and low electrical conductivity, CMCs have been greatly improved in the last decade. CMCs are produced from ceramic fibres embedded in a ceramic matrix, for which several ceramic materials (oxide or non-oxide) are used for the fibres and the matrix. Due to the large diversity of available fibres, the properties of CMCs can be adapted to achieve structural targets. They are especially valuable for structural components with demanding mechanical and thermal requirements. However, with the advent of nanoparticles in this century, the research interests in CMCs are now changing from classical reinforcement (e.g., microscale fibres) to new types of reinforcement at nanoscale. This review paper presents the current state of knowledge on processing and mechanical properties of a new generation of CMCs: Ceramics Nanocomposites (CNCs).

Uncertainty modelling of service life and environmental performance to reduce risk in building design decisions

Life-cycle assessment (LCA) is increasingly used to quantify the environmental impacts of construction materials. However, the relationship between the durability and LCA of these complex products with long life-cycles must be analysed in detail, namely using stochastic data from service life prediction (SLP) studies. However, SLP uncertainty is not yet considered in LCA, thus resulting in insufficiently sound decisions at the design stage. This paper presents the modelling of the uncertainty of SLP using advanced statistical methods and its application in the estimation of SL and corresponding number of replacements of claddings (renderings and stone claddings). These results are used in an interdisciplinary study of SLP and LCA to apply in the stochastic comparison of the LCA of claddings. This methodology aids in the choice of the option with better environmental performance right at the design stage, via the comparison of their standard, deterministic and stochastic LCA results.

Insulation Cork Boards—Environmental Life Cycle Assessment of an Organic Construction Material

Envelope insulation is a relevant technical solution to cut energy consumption and reduce environmental impacts in buildings. Insulation Cork Boards (ICB) are a natural thermal insulation material whose production promotes the recycling of agricultural waste. The aim of this paper is to determine and evaluate the environmental impacts of the production, use, and end-of-life processing of ICB. A “cradle-to-cradle” environmental Life Cycle Assessment (LCA) was performed according to International LCA standards and the European standards on the environmental evaluation of buildings. These results were based on site-specific data and resulted from a consistent methodology, fully described in the paper for each life cycle stage: Cork oak tree growth, ICB production, and end-of-life processing-modeling of the carbon flows (i.e., uptakes and emissions), including sensitivity analysis of this procedure; at the production stage—the modeling of energy processes and a sensitivity analysis of the allocation procedures; during building operation—the expected service life of ICB; an analysis concerning the need to consider the thermal diffusivity of ICB in the comparison of the performance of insulation materials. This paper presents the up-to-date “cradle-to-cradle” environmental performance of ICB for the environmental categories and life-cycle stages defined in European standards.