Inês Flores-Colen

Discussion of Criteria for Prioritization of Predictive Maintenance of Building Façades: Survey of 30 Experts

The practice of predictive maintenance depends significantly on the diagnosis of in-service performance and on the decision criteria for the selection of maintenance tasks. The definition of these criteria is limited because several actors are involved, each with their own perspectives of performance and maintenance needs. This paper discusses a set of 17 criteria to help the maintenance choice for building facades, from three viewpoints: physical performance, risk, and costs. A group of experts was surveyed and 30 answers were received. Therefore, each criterion will be discussed according to the answers collected. The relative importance (using quantitative weights) and subclasses for each criterion are proposed.

Passive Thermographic Inspection of Adhered Ceramic Claddings: Limitation and Conditioning Factors

AbstractAdhered ceramic tiles are one of the most commonly used exterior cladding materials in Portugal. However, various durability problems are also noted by the researchers. A research study was therefore designed to identify in situ inspection techniques that can be used for detecting moisture-content increase and delamination problems of this type of cladding, and for this purpose 16 buildings in Lisbon were inspected by infrared (IR) thermography. In IR thermography, various factors affect data collection and interpretation and this may lead to false or questionable indications. Factors of this nature observed during the in situ passive thermographic inspection of these 16 buildings have been gathered and systematized to support the decision whether to use passive thermography in detecting moisture and delamination problems in an adhered ceramic cladding of a particular building, considering its characteristics. The factors observed were organized in two main groups associated with (1) the building/...

Statistical survey of the pathology, diagnosis and rehabilitation of ETICS in walls

AbstractThis paper presents a statistical survey on the pathology, diagnosis and rehabilitation of ETICS (external thermal insulation composite system) in walls. The development of an expert-knowledge inspection and diagnosis system for this type of cladding implied the creation of classification lists of anomalies, most probable causes, diagnosis methods and repair/maintenance techniques. The collection of data through field work where the tools developed within the proposed system were applied was the basis for this statistical survey. The field work consisted of the visual inspection of 146 facades with ETICS cladding located in various areas in Portugal and aged from 3 to 22 years. The data obtained enable anomalies to be related to their causes and so conclusions can be drawn on the best way to minimize the development of the former and eliminate the latter, at the design and application stages. The study further revealed the main sensitive issues of the cladding system during its service life, highl...

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.

Mechanical Characteristics of Lightweight Mortars on Small-Scale Samples

Occasionally, in laboratory conditions, it can be advantageous to use small-scale specimens, e.g., when the amount of available material is limited or expensive or when there are space limitations. The characteristics of any tested material such as concrete or mortar are affected by the specimens’ size; therefore it is important to consider this effect when estimating the properties of these materials. Despite the extensive studies about the effect of the specimens’ size in concrete, there is a shortage of information about this matter in mortars. This study presented the effects of specimens’ size on the mechanical properties of cement-based lightweight mortars. These included the compressive strength and flexural strength, bulk density, dynamic Young’s modulus, and ultrasonic pulse velocity. For this purpose, statistical analyses were conducted in order to correlate test values from standard samples and small-scale samples and to analyze the feasibility of estimating the mechanical strength from non-destructive tests on small-scale samples. In order to facilitate the production of small-scale specimens, an alternative mixing method was also tested. The results obtained show correlation factors around 0.9, which was found suitable to estimate the mechanical characteristics by using small-scale samples instead of standard specimens. The correlations obtained from the relationships between the results of mechanical strength and non-destructive tests were also evaluated.

Water-Resistance of Mortars with Lightweight Aggregates

The incorporation of lightweight aggregates in cement-based coating mortars contributes to a better performance of some of their physical properties, influencing their hygrothermal behaviour. This paper analyses the effect of some lightweight aggregates (expanded clay, granulated cork and silica aerogel) on the following mortars’ characteristics: porosity, bulk density, capillary water absorption coefficient, drying index and water vapour permeability. The experimental results showed that low percentages of incorporation of lightweight aggregates led to more porous mortars with lower bulk density, higher capillary water absorption coefficient and greater drying facility, relative to the reference cement-based mortar. The incorporation of silica aerogel in cement-based mortars resulted in major differences in terms of water resistance, with significant benefits in terms of the drying process due to their porous structure.

In‐service parameters from façade rendering mortars

Purpose – The purpose of this paper is to analyse two parameters relevant to the physical‐mechanical performance of external renders, mainly, bulk density and apparent or open porosity, by performing laboratory tests on samples collected under real in‐service conditions.Design/methodology/approach – The test procedure (sample preparation and techniques used) and its relationship with the overall performance characteristics and with any anomalies are discussed for each parameter. The analysis of the results covers seven case studies and 15 walls with renders made on site (cementitious and cement‐lime based) and non‐traditional or pre‐mixed renders.Findings – It was concluded that reliable relationships could be established between the test results and other physical parameters relevant to the mechanical and water‐related behaviour of different types of cementitious renders. Notwithstanding the usual drawbacks of laboratory tests (more time‐consuming, higher costs and greater destruction of the walls), the ...

In-situ Techniques for Mechanical Performance and Degradation Analysis of Rendering Walls

Rendered building facades frequently require repair due to the environmental exposure to which they are subjected during their life cycle. The evaluation of in-service degradation assumes a crucial role in the determination of adequate levels of performance throughout this period. To complement visual inspection some in-situ testing techniques may be used, preferentially non-destructive ones, in order to characterize the in-service behavior of renders. The paper aims to evaluate the advantages of using visual inspection (including auxiliary diagnosis techniques) and selected in-situ techniques (infrared thermography, rebound hammer and ultrasound tests) for the evaluation of their state of deterioration and the mechanical performance of the renders, respectively. The main objective of the study is to evaluate the potential and feasibility of each technique, as well as the correlation between the different results and the way that the combined information can complement the visual inspection. Three experimental campaigns were performed and different types of renders were analyzed for various in-service conditions. The results allowed concluding that there are advantages in the cross-comparison of different results, which in certain situations can complement the visual inspection. Furthermore, it was also concluded that the sensitivity and potential of each technique differs depending on the type of deterioration present.

Inspection, Diagnosis, and Rehabilitation System of Door and Window Frames

AbstractThis paper presents a support system for the inspection, diagnosis, and rehabilitation of door and window frames with the purpose of standardizing and systemizing the procedures of those re...

Maintenance Planning of Pitched Roofs in Current Buildings

AbstractThe implementation of a roof maintenance plan is a key element to control in-service system performance by monitoring the deterioration factors, types of anomalies, and their causes. A cont...