scholarly journals Degradation Assessment of Natural Stone Claddings over Their Service Life: Comparison between Tehran (Iran) and Lisbon (Portugal)

Buildings ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 438
Author(s):  
S. H. Mousavi ◽  
Ana Silva ◽  
Jorge de Brito ◽  
A. Ekhlassi ◽  
S. B. Hosseini

Now more than ever, the construction sector is aiming to adopt more sustainable solutions. To achieve this purpose, more durable solutions must be adopted, making rational decisions at the design and maintenance stages regarding the conditions of environmental exposure and use. In this sense, knowledge regarding the service life of building components is crucial. This knowledge should not be a general concept, or a standard value, and adapting practices from one country to another is extremely challenging. In this sense, this study analyses the service life of natural stone claddings. We adopt a methodology initially proposed for Lisbon (Portugal), intending to evaluate its applicability to other geographical contexts, in order to perform a more reliable service life prediction of stone claddings located in Tehran (Iran). An estimated service life of 65 years was obtained for a sample of 162 stone claddings directly adhered to the substrate, located in Tehran, which were analysed by in situ inspections. The impact of different conditions (e.g., type of stone and environmental exposure conditions) on the service life of stone claddings in Tehran was quantified, which revealed that the exposure to environmental agents, such as wind, rain and pollutants, is the main cause of degradation of the natural stone claddings.

Buildings ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 615
Author(s):  
Joana Barrelas ◽  
Ilídio S. Dias ◽  
Ana Silva ◽  
Jorge de Brito ◽  
Inês Flores-Colen ◽  
...  

Façade claddings, as the outer protection layer of the building’s envelope, are directly exposed to environmental degradation agents. The façades’ orientation and their distance from the sea, among other location and protection-related factors, influence their vulnerability to climate loads, in particular wind and air humidity. These loads, as well as exposure to air pollution, affect the degradation process of claddings and the durability of façades. Therefore, studying the impact of the environmental exposure conditions on the service life of different external claddings provides useful information on their performance over time, which can support (i) decision-makers in the selection of the best façade cladding solutions and (ii) further research on the impact of climate change on building components. This study covers six types of cladding: rendered façades (R), natural stone cladding (NSC), ceramic tiling system (CTS), painted surfaces (PS), external thermal insulation composite systems (ETICS), and architectural concrete façades (ACF). Three hundred façades located in Portugal are analysed according to three main groups of variables, which characterize (i) the façades, (ii) their degradation condition, and (iii) the environmental deterioration loads and context. The statistical analysis results reveal that the environmental variables affect the cladding degradation process. South-oriented façades present lower degradation conditions than façades facing north. The distance from the sea and high exposure to pollutants add to the degradation conditions, reducing the expected service life of façades. The results reveal that claddings can be organized according to two main groups: the most durable (CTS, NSC, and ACF) and the least durable (R, PS, and ETICS) systems. This study enables a comprehensive analysis of the data, useful to draw conclusions about the influence of environmental exposure conditions on the degradation and service life of façade claddings.


Buildings ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 9 ◽  
Author(s):  
Shahana Janjua ◽  
Prabir Sarker ◽  
Wahidul Biswas

The environmental performance assessment of the building and construction sector has been in discussion due to the increasing demand of facilities and its impact on the environment. The life cycle studies carried out over the last decade have mostly used an approximate life span of a building without considering the building component replacement requirements and their service life. This limitation results in unreliable outcomes and a huge volume of materials going to landfill. This study was performed to develop a relationship between the service life of a building and building components, and their impact on environmental performance. Twelve building combinations were modelled by considering two types of roof frames, two types of wall and three types of footings. A reference building of a 50-year service life was used in comparisons. Firstly, the service life of the building and building components and the replacement intervals of building components during active service life were estimated. The environmental life cycle assessment (ELCA) was carried out for all the buildings and results are presented on a yearly basis in order to study the impact of service life. The region-specific impact categories of cumulative energy demand, greenhouse gas emissions, water consumption and land use are used to assess the environmental performance of buildings. The analysis shows that the environmental performance of buildings is affected by the service life of a building and the replacement intervals of building components.


Author(s):  
Nicolas Francart ◽  
Torun Widström ◽  
Tove Malmqvist

Abstract Purpose Previous life cycle assessments (LCAs) of buildings and building components show a broad range of values for the impact of maintenance and replacement, some highlighting these operations as major hotspots while others consider them insignificant. This article highlights methodological aspects explaining this discrepancy. The influence of three aspects is investigated further in a case study of façade materials: the reference study period (RSP), service life data, and the use of a round-up number of operations or annualized impacts. Methods A comparative LCA of seven façade alternatives is carried out as an illustrative case study. For each alternative, global warming potential (GWP) is calculated using three possible RSPs, four possible material service lives (one from industry practitioners and low, standard and high values from a generic database), and two possible calculation methods (round-up or annualized impacts). Results and discussion While the same façade alternative had the lowest GWP in all cases, different methodological choices significantly affected the GWP and respective ranking of other alternatives. Some alternatives showed a significant increase in GWP over longer RSPs, while others were still dominated by the impact of initial production after 200 years. In nearly all cases, generic service life data lead to a higher GWP than data from industry practitioners. Major discrepancies were found between generic and practitioner data in some cases, e.g., for the brick façade. In most cases, annualized impacts led to a slightly lower (or equal) GWP than using a round-up number of operations. However, when a major operation happens shortly before the end of the RSP, the annualized method leads to considerably lower GWP. Conclusions Maintenance and replacement are rarely significant over a 50-year RSP but sometimes become hotspots over longer RSPs. Using round-up operations or annualized impacts does not make much difference in average, but leads to significantly different results in specific cases. As building LCA enters certification and regulation, there is a need to harmonize such methodological choices, as they affect LCA results, hotspot identification, and recommendations. Discrepancies in service life data also call for the gathering of reliable data.


2020 ◽  
Vol 30 (Supplement_5) ◽  
Author(s):  
◽  

Abstract   Childhood obesity has grown to become one of the most dramatic features of the global obesity epidemic, with long-term consequences. The spread of obesity has been fueled by changes in social norms and living environments that have shaped individual behaviours making them conducive to excessive and imbalanced nutrition, sedentary lifestyles, and ultimately obesity and associated diseases. The STOP project will aim to generate scientifically sound, novel and policy-relevant evidence on the factors that have contributed to the spread of childhood obesity in European countries and on the effects of alternative technological and organisational solutions and policy options available to address the problem. STOP will translate the evidence gathered and generated into indicators and measurements, policy briefs and toolkits and multi-stakeholder frameworks. A special focus of STOP is understanding the stakeholders' networks and drivers of stakeholders' action. STOP will establish new ways for policy-relevant evidence to be generated, made available and used in the design and implementation of effective and sustainable solutions for childhood obesity at the EU, national and local levels. Each of the policy work packages will: Produce evidence syntheses and impact simulations for different policy approaches;Assess selected policy approaches and actions in children cohorts and other relevant settings;Devise policy toolkits and policy guidance to support the adoption and implementation of specific actions by relevant actors;Establish a country-based European accountability and monitoring framework in each policy area. The workshop aims to: Showcase the impact of different policy options evaluated throughout the STOP project;Increase participants' understanding and awareness of the opportunities and challenges associated with the implementation of selected policies;Increase awareness of public health professionals of the importance of overcoming siloes in identifying and implementing public health policies;Increase the understanding of multi-stakeholder engagement. The discussion will explore the role of stakeholders across different policy areas. We will explore the different definitions of “stakeholders” and “multi-stakeholders” engagement. This will also be an opportunity to explore some of the benefits, risks and challenges around stakeholder engagement, and explore what are the different types of stakeholders involved in these policies as well as their roles. The workshop will offer an opportunity to: Inform participants about existing physical activity, regulatory and fiscal policies to address childhood obesity;Inform participants about new, innovative EU-level projects that aim to address childhood obesity;Outline preliminary findings of the STOP project with regards to the effectiveness of the evaluated policies;Identify some of the gaps and limitations of existing policies and discuss some of the steps to ensure successful policy implementation. Key messages Present new evidence on what policy approaches work in addressing key determinants of childhood obesity. Showcase findings on the attitudes of different stakeholders towards obesity policies, and debate the benefits, risks and challenges of multi-stakeholder engagement.


2018 ◽  
Vol 203 ◽  
pp. 07005 ◽  
Author(s):  
Abdurrasheed Sa'id Abdurrasheed ◽  
Khamaruzaman Wan Yusof ◽  
Husna Bt Takaijudin ◽  
Aminuddin Ab. Ghani ◽  
Muhammad Mujahid Muhammad ◽  
...  

Subsurface drainage modules are important components of the Bio-ecological Drainage System (BIOECODS) which is a system designed to manage stormwater quantity and quality using constructed grass swales, subsurface modules, dry and wet ponds. BIOECODS is gradually gaining attention as one of the most ecologically sustainable solutions to the frequent flash floods in Malaysia and the rest of the world with a focus on the impact of the subsurface modules to the effectiveness of the system. Nearly two decades of post-construction research in the BIOECODS technology, there is need to review findings and areas of improvement in the system. Thus, this study highlighted the key advances and challenges in these subsurface drainage modules through an extensive review of related literature. From the study, more work is required on the hydraulic characteristics, flow attenuation and direct validation methods between field, laboratory, and numerical data. Also, there is concern over the loss of efficiency during the design life especially the infiltration capacity of the module, the state of the geotextile and hydronet over time. It is recommended for the sake of higher performance, that there should be an onsite methodology to assess the permeability, rate of clogging and condition of the geotextile as well as the hydronet over time.


2020 ◽  
Vol 5 (9) ◽  
pp. 77
Author(s):  
Cláudia Ferreira ◽  
Ana Silva ◽  
Jorge de Brito ◽  
Ilídio S. Dias ◽  
Inês Flores-Colen

Existing maintenance policies have several limitations, mainly due to the lack of knowledge regarding the durability and performance of buildings. Usually, the maintenance policies are insufficiently accurate, neglecting the risk of failure over time and the global costs associated with repairs. In this study, a condition-based maintenance model, based on Petri nets, is proposed to evaluate the impact of three maintenance strategies of ceramic claddings in pitched roofs (CCPR): MS1—only total replacement; MS2—composed of total replacement and minor intervention and MS3—composed of total replacement, minor intervention and cleaning operations. In this study, 146 CCPR were inspected in situ, with a total area of 43,991.6 m2. The remaining service life of the CCPR; the global costs over the claddings’ lifetime (considering inspection, maintenance, replacement and disposal costs); the claddings’ degradation condition and the number of replacements during the time horizon are used to evaluate the performance of the different maintenance strategies through a simplified multi-criteria analysis. The results show that the gains in performance, in terms of expected service life and durability, of the consideration of preventive maintenance actions (minor interventions or cleaning operations) outweigh the increase of the operation costs.


Author(s):  
A. Krasheninin

Modern vehicles operated on the railways of Ukraine have almost exhausted or exceeded their resource. The overuse of financial and material resources for their maintenance continues. The standard service life of vehicles was calculated on stable economic conditions of use of vehicles and their timely updating in process of aging. The service life of modern vehicles is determined by the influence of many factors, the disregard of which can lead to significant costs, even in compliance with the standard service life. For railway transport, these factors need modern clarification, as in operation their service life often exceeds the standard or, as for intermodal transport, the service life does not have a strict justification. Accordingly, the article analyzes the issues of assessing the impact on the service life of vehicles of the components of the cost of its maintenance and average daily mileage. It is shown that, firstly, the definition of the service life of vehicles must be linked to the cost of vehicle development, its creation, testing and production, the cost of operation and storage, as well as additional costs, and secondly , with the optimal average daily mileage, at which all the costs are minimal.


10.26458/1845 ◽  
2018 ◽  
Vol 18 (4) ◽  
pp. 75-93
Author(s):  
Viorica Jelev

 This paper presents the existing situation at national and world level considering the available water resources, their vulnerability especially in the mountains areas, the impact of climate changes, the possible conflicts regarding the intensification of water shortage in some regions of the world. I also present a case study on forests in Romania. Beginning with the general data mentioned above, we point out the specific peculiarities of the mountain area hydrology for identifying some aspects which are specific to the mountain water relationship. The analysis is necessary as no specifications regarding the mountain hilly or plain areas are done in the activity regarding waters management. Waters are managed unitary on river basins considering some general principles, unanimously recognized, well reflected into the national and international regulations. As a first stage, traditional economic activities are identified in the relationship of the mountain areas inhabitants with water but also some present approaches. The way the mountain areas inhabitants knew how to live together and capitalize water resources represents a model and impulse for coming back to such sustainable solutions but capitalizing the advantages of modern technologies. Each of these activities referring to waters which take place in the mountains area can represent ways for the research activity and future thorough studies from the technical, economic, social, cultural-traditional point of view and also for environment protection. A main preoccupation might have connection with the evolution of agricultural activities in the mountains area considering the climate changes and a possible “migration” towards higher areas of some agricultural practices specific to lower areas. The paper also shows a small example of the regaining by the locals of a community of an important resource for their lives in the hands of corporations: the forests defaced by HOLZINDUSTRIE SCHWEIGHOFER and stop flooding villages. 


PEDIATRICS ◽  
1974 ◽  
Vol 53 (5) ◽  
pp. 816-817
Author(s):  
Audrey K. Brown

Because of the anemia or bleeding that may herald the adverse impact of any agent upon the hematopoietic system, the capacity of drugs, insecticides, lead, and other agents to cause malfunction of this system has long been recognized. As a matter of fact, the major therapeutic step in the management of recognized aplastic anemia is to separate the child from his environment even before the offending agent has been identified. There is, however, no good evidence to date that the child or neonate is singularly susceptible to aplastic anemia or neutropenia from such agents. In response to other agents, there is a special susceptibility of the hematopoietic system in the fetus and newborn. One special feature of the fetus affecting susceptibility to environmental agents is that, in a sense, he is trapped in his environment; and, we cannot extract him early enough from exposures via the mother and placenta. The smoking mother, the heroin addict, and the mother exposed to industrial pollutants are the conduits through whom poisons may reach the fetus. The special features of fetal physiology, the stage of organ development, and the phase of physiologic maturity dictate the uniqueness of response at a particular time in gestation or immediately after delivery. CHEMICAL EFFECTS ON RED CELLS OR PLATELETS In the last trimester women take an average of 8.7 drug agents or vitamins and 80% of these agents are taken without medical supervision. The impact of these agents on red cells, white cells, platelets, the fetal coagulation system, and on the appearance of pigments formed during red cell destruction are in some instances predictable because of the growing fund of information concerning the unique physiology of these cells and systems in the fetus and newborn.


Author(s):  
Heather M. W. Petrelli

What leads to academic success? Why are some students able to achieve academically and others not? A breadth of research exists supporting the notion of motivation as having a significant impact on academic success. This chapter investigated historical and theoretical developments of motivation from the Greek Philosophers, through the Industrial Revolution, to the perspective of motivation in fulfilling psychological needs. Once the general concept of motivation is fully exhausted, academic motivation is explored from theoretical foundations to current research on factors influencing academic motivation and the impact of academic motivation on academic achievement. This foundation has practical implications for assessment of motivation and curricular and program development as a result.


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