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Sustainable building repair: A K-means approach to addressing fissures in ceramic brick partition walls
No full textThe purpose of this work is to determine, catalogue, and quantify failures appearing in ceramic brick partition walls after the delivery of buildings, based on claims filed by users and on the philosophy of 'learning from failures'. To examine the more than 600 cases presented, technical affinity groups were defined for the descriptors used, a series of checks were carried out using cluster analysis, a proprietary procedure was implemented for calculating the risk of demands being filed, and a final risk assessment process was made, divided into five categories. It was found that there is a recurring presence of large cracks due to incorrect bond/connections between brick wall panels. The repair of the most frequent cause of 'Incorrect lock/connection of the panes' was analysed in terms of CO2 emissions. The study of a large number of real cases, such as has been done in this paper, can allow us to advance and define new strategies to significantly minimise future failures, making it difficult for them to reach the usage phase of the building. The access to a type of data source never before used in the world to corroborate the types of damages and causes that occur in partitions (indicating their recurrence and evaluating user dissatisfaction) is unprecedented
Restoring History: The Revitalisation of a Chape
No full textThis article describes the main rehabilitation works carried out at the Chapel of S. João do Deserto. During the restoration process, non-structural and structural anomalies were identified. The structural ones were causing cracks in the walls. While the Chapel had undergone several interventions over the years, not all of them had been successful, and some problems persisted to this day. A thorough analysis of the structure's behavior was essential to properly address these issues and prevent future damage. A structural reinforcement was carried out at the level of the roof, in addition to the consolidation of the masonry walls and mortars. To maintain the Chapel's original layout and identity, traditional materials and techniques were used whenever possible
Using forensic reports to manage the probability of lawsuits being filed in relation to pitched roofs: the case of Madrid
No full textRoofs are among the construction units in buildings with the highest number of deficiencies and problems. Given their direct and constant exposure to weather (temperature, wind, rain, snow…), even minor issues can lead to important pathology processes if not addressed early on. This research examines unresolved issues of pitched roofs in the capital of Spain which eventually led to the filing of lawsuits. Different types of deficiencies were detected (humidities, condensations, fissures…) and classified according to their recurrence. The thousands of pages of forensic reports presented to the courts were consulted and analysed to determine the probability/risk of recurrence, based on a number of factors. Among them is the causal origin (according to the properties/characteristics of the materials or to the placement/application conditions) and the respective building typologies (single-family houses or multi-storey buildings). The results that were obtained were calculated through weighted risk matrices of the existing interrelations, before determining the levels of joint severity and the classification categories according to the final operational value
Exterior bricks walls: learning non-quality through failures and their climate-pathological distribution
No full textThe object of this research was to identify the list of climatological variables involved in the appearance of construction failures in the external walls of dwellings through the analysis of over one thousand cases. The data source used consisted of the judicial records of the Justice Administration, a source to which few researchers have access, given the dispersion of the data and the permissions required to access it. Once obtained, all situations pertaining to dwellings were read and annotated, until 100\% of the cases were accounted for, and percentages of recurrence were calculated for each of the nine different types of failures that were described. A study was carried out by so-called strips of climatic location according to four climatological variables (situation, latitude, climate, and annual rainfall) that were sorted from largest to smallest to obtain the ranks of pathology concentration according to the resulting preponderance. Using these results, technicians will be able to identify the most problematic climate-geographical areas by determining the ranks of normalized frequencies, allowing them to take the necessary measures during the construction process. The lessons learned can be incorporated into maintenance plans to optimize preventive maintenance frequency and actions
Degradation and Deterioration Processes in Swimming Pools Adjoining Real Estate Developments
No full textRegrettably, the existence of multiple deficiencies in construction has become commonplaceto the point of appearing to be a part and parcel of the very process of executing construction works; many now consider it inevitable. In no other industrial sector does the production ofan object lead most stakeholders to a growing degree of dissatisfaction – not only future users but also, for different reasons, the professionals participating in the process. Certainly, one of the reasons for this is that each building is normally a prototype (designed and built for the first time), implying uncertainty and the lack of studying possible difficulties until they have emerged.
There is yet another series of reasons that worsen this situation: often, designers do not take note of problems (and their solutions) to take them into account in future designs. Neither do construction companies foresee corrective measures to problems – trying instead to quicklycover errors or draw economic benefits from changing the execution procedure.
When the owner of a house experiences certain construction problems that are not solved within the warranty period, they often have no choice but to resort to the judicial route. In thisprocess, an expert is charged with drafting a report describing the existence of the existing flaws or degradations. These reports are paid for by the insurance company of the technicians under complaint and they constitute the data source of this study – namely, the reports of the civil responsibility insurance of Spanish technical architects.
One the lawsuit is initiated, the existence of said problems is examined, along with their na- ture, extension, and type, based on the technical reports. Once the judge rules on the corre- sponding result, and if so willed by the defendants, the disputing parties can appeal to a highercourt. In such a case, the suit re-commences, until the legal procedure definitively ends. This long technical and judicial path leads to the validation of the data source used and to the find- ings presented in this communication regarding swimming pools adjoining houses.
A total of 146 cases were analysed and characterised into 3 different types of degradations. The first type is ‘settling’ (DE1) of the construction element itself, occurring in about 60% of situations. The second type is ‘fissurations’, occurring in 24% of occasions. With regard to the pathology origin of these cases, 4 different types were
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found, with the main one being the ‘absence or deficiency of soil compaction’ underneath the swimming pools (PO1=71%). In ad- dition to this data, this research produced an interrelation matrix for these two parameters, forming the binomial pairs referred to as ‘deterioration process’. This information is without precedents in the international scientific literature that was reviewed
Rehabilitation of the Penhas Chapel in Mitras’s Homestead
No full textThis article describes the main rehabilitation works carried out at Capela das Penhas. Some struc- tural anomalies were found that were causing cracks in the walls and vaults. The Chapel had already undergone several interventions over the years, but not all of them had been successful, with some problems prevailing until today. The correct analysis of the structure's behavior was essential to be able to correct them and avoid further problems. We tried to maintain the same layout and identity of the Chapel, using traditional materials and techniques, whenever possible
A Generalized Estimating Equations Approach to Model Heterogeneity and Time Dependence in Capture-Recapture Studies
No full textIndividual heterogeneity in capture probabilities and time dependence are fundamentally important for estimating the closed animal population parameters in capture-recapture studies. A generalized estimating equations (GEE) approach accounts for linear correlation among capture-recapture occasions, and individual heterogeneity in capture probabilities in a closed population capture-recapture individual heterogeneity and time variation model. The estimated capture probabilities are used to estimate animal population parameters. Two real data sets are used for illustrative purposes. A simulation study is carried out to assess the performance of the GEE estimator. A Quasi-Likelihood Information Criterion (QIC) is applied for the selection of the best fitting model. This approach performs well when the estimated population parameters depend on the individual heterogeneity and the nature of linear correlation among capture-recapture occasions
Harmonic oscillations on non-homogeneous media
No full textWe introduce a model to study the vibrational properties of non-homogeneous materials. In our work these materials, naturally idealized, are composed by one dimensional chains of harmonic oscillators represented by an alternating sequence of particles and springs. Despite the system has explicit solutions since it is linear, the formulas can be very complicated. We use homogeneous chains as building blocks for characterizing the whole system and the global dynamics. In particular, we determine the solution for a chain composed of two distinct homogeneous chains in terms of the original solutions for these two homogeneous chains, when uncoupled. This gives us a general procedure to deal easily with hon-homogeneous chains
The Role of Non-Negative Polynomials For Rank-One Convexity and Quasi Convexity
No full textWe stress the relationship between the non-negativeness of polynomials and quasi convexity and rank-one convexity. In particular, we translate the celebrated theorem of Hilbert ([3]) about non-negativeness of polynomials and sums of squares, into a test for rank-one convex functions defined on 2 × 2-matrices. Even if the density for an integral functional is a fourth-degree, homogeneous polynomial, quasi convexity cannot be reduced to the non-negativeness of polynomials of a fixed, finite number of variables
Chapter: Carcinogenesis.
No full textCancer is a complex disease with multiple causes. Many intrinsic and extrinsic factors influence the development of cancer. Intrinsic or host factors include age, sex, genetics, immune system, metabolism, and hormones. Extrinsic factors are divided in different groups, as physical (different types of non-ionizing and ionizing radiations); chemical (as some mineral or organic substances); and biological (produced by some living organisms, for instance, some plants, virus, bacteria or fungi). Intrinsic and extrinsic factors can interact with one another to influence the development of cancer. In this article, we will discuss all the varied aspects of research that will ultimately lead to the prevention of cancer in man