scholarly journals Susceptibility of earth-based construction materials to fungal proliferation: laboratory and in situ assessment

2019 ◽  
Vol 3 ◽  
pp. 140-149 ◽  
Author(s):  
Alexis Simons ◽  
Alexandra Bertron ◽  
Christophe Roux ◽  
Aurélie Laborel-Préneron ◽  
Jean-Emmanuel Aubert ◽  
...  
Keyword(s):  
Air Quality ◽  
Manufacturing Process ◽  
Building Materials ◽  
Construction Materials ◽  
Microbial Density ◽  
Microbial Proliferation ◽  
Materials Used ◽  
Ecological Construction ◽  
The Impact

The impact of building materials on the environment and the health of occupants is nowadays a priority issue. Ecological construction materials such as earthen materials are currently experiencing a regain of interest due to both ecological and economic factors. The microbial proliferation on indoor materials can induce a deterioration of the building air quality and lead to an increase of health risks for the occupants. The issue of indoor air quality raises questions about the use of earthen building materials and their possible susceptibility to fungal development. The microflora of earthen materials and their ability to grow on such support are indeed poorly studied. This study focused on the quantification of both bacterial and fungal microflora along the manufacturing process. The impact of extreme humidity, simulating a hydric accident, on microflora development was analyzed on the surface and inside earthen bricks. The initial microflora of these materials was dramatically reduced during the manufacturing process, especially after heat treatment for drying. Proliferation of remaining microorganisms was only observed under high humidity condition, in particular for earthen materials with vegetal aggregates. Moreover, in situ samplings were performed on naturally dried earthen materials used in buildings. The characterization of the microbial density revealed a higher microbial density than on manufactured specimens, while microbial concentration and detected taxa seemed mainly related to the room use and building history. These results provide a better understanding of microbial proliferation on these materials.

scholarly journals Fire Resistance Behaviour of Geopolymer Concrete:An Overview

Buildings ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 82
Author(s):  
Salmabanu Luhar ◽  
Demetris Nicolaides ◽  
Ismail Luhar
Keyword(s):  
Compressive Strength ◽  
Thermal Resistance ◽  
Building Materials ◽  
Elevated Temperatures ◽  
Construction Materials ◽  
Flexural Behavior ◽  
Thermal Shrinkage ◽  
Physico Chemical ◽  
The Impact ◽  
Loss Of Strength

Even though, an innovative inorganic family of geopolymer concretes are eye-catching potential building materials, it is quite essential to comprehend the fire and thermal resistance of these structural materials at a very high temperature and also when experiencing fire with a view to make certain not only the safety and security of lives and properties but also to establish them as more sustainable edifice materials for future. The experimental and field observations of degree of cracking, spalling and loss of strength within the geopolymer concretes subsequent to exposure at elevated temperature and incidences of occurrences of disastrous fires extend an indication of their resistance against such severely catastrophic conditions. The impact of heat and fire on mechanical attributes viz., mechanical-compressive strength, flexural behavior, elastic modulus; durability—thermal shrinkage; chemical stability; the impact of thermal creep on compressive strength; and microstructure properties—XRD, FTIR, NMR, SEM as well as physico-chemical modifications of geopolymer composites subsequent to their exposures at elevated temperatures is reviewed in depth. The present scientific state-of-the-art review manuscript aimed to assess the fire and thermal resistance of geopolymer concrete along with its thermo-chemistry at a towering temperature in order to introduce this novel, most modern, user and eco-benign construction materials as potentially promising, sustainable, durable, thermal and fire-resistant building materials promoting their optimal and apposite applications for construction and infrastructure industries.

scholarly journals Effects of Infills in the Seismic Performance of an RC Factory Building in Pakistan

Buildings ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 276
Author(s):  
Nisar Ali Khan ◽  
Giorgio Monti ◽  
Camillo Nuti ◽  
Marco Vailati
Keyword(s):  
Numerical Model ◽  
Construction Materials ◽  
Building Codes ◽  
Construction Technique ◽  
Infill Walls ◽  
Mortar Strength ◽  
Materials Used ◽  
Seismic Response Of Buildings

Infilled reinforced concrete (IRC) frames are a very common construction typology, not only in developing countries such as Pakistan but also in southern Europe and Western countries, due to their ease of construction and less technical skills required for the construction. Their performance during past earthquakes has been in some cases satisfactory and in other cases inadequate. Significant effort has been made among researchers to improve such performance, but few have highlighted the influence of construction materials used in the infill walls. In some building codes, infills are still considered as non-structural elements, both in the design of new buildings and, sometimes, in the assessment of existing buildings. This is mainly due to some difficulties in modeling their mechanical behavior and also the large variety of typologies, which are difficult to categorize. Some building codes, for example, Eurocode, already address the influence of infill walls in design, but there is still a lack of homogeneity among different codes. For example, the Pakistan building code (PBC) does not address infills, despite being a common construction technique in the country. Past earthquake survey records show that construction materials and infill types significantly affect the seismic response of buildings, thus highlighting the importance of investigating such parameters. This is the object of this work, where a numerical model for infill walls is introduced, which aims at predicting their failure mode, as a function of some essential parameters, such as the friction coefficient between mortar and brick surface and mortar strength, usually disregarded in previous models. A comprehensive case study is presented of a three-story IRC frame located in the city of Mirpur, Pakistan, hit by an earthquake of magnitude 5.9 on 24 September 2019. The results obtained from the numerical model show good agreement with the damage patterns observed in situ, thus highlighting the importance of correctly modeling the infill walls when seismically designing or assessing Pakistani buildings that make use of this technology.

scholarly journals NDT Methods Suitable for Evaluation the Condition of Military Fortification Construction in the Field

2020 ◽  
Vol 10 (22) ◽  
pp. 8161
Author(s):  
Zezulová Eva ◽  
Hasilová Kamila ◽  
Komárková Tereza ◽  
Stoniš Patrik ◽  
Štoller Jiří ◽  
...  
Keyword(s):  
Residual Strength ◽  
Fiber Reinforced Concrete ◽  
Protective Structure ◽  
Steel Fiber Reinforced Concrete ◽  
Degree Of Damage ◽  
Materials Used ◽  
Protective Structures ◽  
The Impact ◽  
Non Destructive

The protective structure is designed to protect the live force against the impact of a shock wave and projectiles, it cannot be diagnosed by the destructive method which devalues the protective structure by sampling. The authors are looking for a combination of suitable non-destructive technology (NDT) methods that would be used in the future to prove the degree of damage to cement-based protective structures after an explosion. This article represents the first part of an experiment designed to verify the applicability of NDT methods, to evaluate the degree of damage of the protective structure in the field. The experiment consists of three parts. The first part is a laboratory verification of the initial material characteristics of the materials used. The first test set of structural elements is made of steel fiber-reinforced concrete. The elements are evaluated using NDT methods and for comparison by destructive laboratory methods. The second part is the impact of structures using explosion and evaluation of the condition of structures using NDT methods in the field. The last part is used to verify the results of the NDT method, which ensures the residual strength of the structure in the laboratory and try to find the relationship between changes in the results of NDT methods and the residual strength. Radiography was included in the introductory and concluding parts of the experiment to verify the results. Although this method is not suitable for using in-situ, it is the only standardized method of the NDT methods used.

The impact of information on perceived air quality ??organic? vs. ?synthetic? building materials

Indoor Air ◽  
2007 ◽  
Vol 17 (2) ◽  
pp. 130-134 ◽  
Author(s):  
K. Wilkins ◽  
P. Wolkoff ◽  
H. N. Knudsen ◽  
P. A. Clausen
Keyword(s):  
Air Quality ◽  
Building Materials ◽  
The Impact

Comparison of Mechanical Properties of Fly Ash Artificial Geopolymer Aggregates with Natural Aggregate

2015 ◽  
Vol 754-755 ◽  
pp. 290-295 ◽  
Author(s):  
Alida Abdullah ◽  
Ku Amirrul Rahman Ku Yin ◽  
Mohd Mustafa Al Bakri Abdullah ◽  
Kamarudin Hussin ◽  
Mien Van Tran
Keyword(s):  
Mechanical Properties ◽  
Fly Ash ◽  
Specific Gravity ◽  
Water Absorption ◽  
Raw Materials ◽  
Construction Materials ◽  
High Water ◽  
Natural Aggregate ◽  
Materials Used ◽  
The Impact

This study was conducted to compare the mechanical properties of fly ash artificial geopolymer aggregates with natural aggregate (rock) in term of its impact strength, specific gravity and water absorption.The raw materials used were fly ash, sodium hydroxide, sodium silicate and natural aggregate. After the artificial geopolymer aggregate has been produced, its water absorption, specific gravity and aggregate impact test has been done. All results obtained were compared to natural aggregate. The result shows that the fly ash geopolymer aggregate are lighter than natural aggregate in term of its specific gravity. The impact value for fly ash artificial geopolymer aggregate slightly high compared to natural aggregate while it has high water absorption value compared to natural aggregate. As conclusion, the fly ash artificial geopolymer aggregate can be used as one of the construction materials in concrete as an alternative for coarse aggregate besides natural aggregate with more lightweight properties.

scholarly journals INTERNATIONAL TRENDS AND CURRENT CHALLENGES OF CONSTRUCTION MATERIALS MARKET DEVELOPMENT

2020 ◽  
Author(s):  
Yulia Orlovska ◽  
◽  
Daria Havrylenko ◽  
Keyword(s):  
Real Estate ◽  
Construction Industry ◽  
Information And Communication Technologies ◽  
Building Materials ◽  
Construction Materials ◽  
Construction Sector ◽  
International Trends ◽  
The World ◽  
The Impact ◽  
Construction Services

The main international trends in the world market of construction materials and services have been analyzed. The dynamics of world GDP and exports of construction services for the period 2000-2019 has been studied and a conclusion is made on the impact of economic crises on their growth rates. It has been determined that the dynamics of world exports of construction services is characterized by high instability with peaks of growth and decline, and is more sensitive than GDP growth. It has been noted that overcoming the crisis in the export sector of construction services takes more time and occurs with an approximate two-year time lag compared to GDP dynamics. The share of the construction industry in the world GDP by the degree of development has been analyzed. The reasons for the decline in the share of the construction industry in countries with economies in transition have been substantiated. It has been noted that in the developed countries the share of the construction sector is accounted for by real estate management activities related to maintenance, rent, purchase and sale and other transactions with land and real estate. The forecast values of growth of the market of building materials and services till 2030 have been given. The essence of the term «wide construction» has been revealed and the structure of this sector in different countries of the world is shown. The main exporters in the world construction market have been given and the structural distribution of the largest construction companies in the world ranking by country of origin has been analyzed. The dynamics of income level in the construction industry market for the period 2011-2018 has been studied. It has been noted that an important area of the construction sector is the market of roofing and facade materials and the world's largest companies for the production of this type of construction materials have been revealed. Conclusions on the essence of global transformations of the market of building materials and services have been made, and also it has been defined that they are caused by transnationalization of corporate structure of the market, influence of scientific and technical progress and information and communication technologies on world centers as well as the emergence of the concept of «sustainable construction» in the course of humanity for sustainable development.

scholarly journals Indoor radon assessment in kindergartens: towards a national action plan

2021 ◽  
Vol 9 (2) ◽  
Author(s):  
Danila Carrijo da Silva Dias ◽  
Nivaldo Carlos Da Silva ◽  
Wanilson Luiz Silva ◽  
Marcos Vinícius Rodrigues
Keyword(s):  
Indoor Radon ◽  
Action Plan ◽  
Construction Materials ◽  
Mean Value ◽  
High Variability ◽  
Local Perception ◽  
Geometrical Mean ◽  
Materials Used ◽  
National Programs ◽  
The Impact

The study presents the results of indoor radon monitoring of 342 public kindergarten rooms of a Brazilian municipality within a region featuring high natural radioactivity. Facility characterization local perception assessment were also conducted. Rooms were monitored by exposure of ATD detectors for an average 356 days. Monitoring resulted in arithmetic and population weighted means of 83 and 82 Bq m-3 respectively, while a geometrical mean value of 61 Bq m-3 was estimated. Concentrations ranged between < 3 and 697 Bq m-3 while 8.1% of rooms presented values above 200 Bq m-3 (in different units), where similarities in construction materials used in floors were noted. High variability was observed among regions, CEI units within a region and even rooms within a unit. The collected data on room ventilation elucidated challenges to large monitoring programs when evaluating the impact of human habits and window characteristics in results. The high variability of results poses challenges to the establishment of national programs in large and diverse areas such as Brazil. The first indoor radon study in children facilities in the country represents an important step towards it.

scholarly journals Strength, sustainability and affordability of bamboo and mud bricks as materials used in local construction

2019 ◽  
Vol 2 (1) ◽  
Author(s):  
Leopold Mbereyaho ◽  
Jean de Dieu Mutabaruka ◽  
Abaho G. Gershome ◽  
Armel Ineza ◽  
Ezra Ngirabatware
Keyword(s):  
Compressive Strength ◽  
Cost Estimation ◽  
Building Materials ◽  
Construction Materials ◽  
Conventional Concrete ◽  
Environment Friendly ◽  
Study Results ◽  
Mud Bricks ◽  
Materials Used ◽  
Sisal Fibers

The construction industry is one of the rapidly growing and the cost analysis suggests that the materials cost is constantly increasing. The continuous extraction of aggregates intensively used in the field is negatively acting to the environment. Therefore research in construction materials should focus not only on discovering new alternative materials but also in appreciating the quality of those locally available for their better application. This research aimed at evaluating the performance of bamboo and mud bricks as two available local building materials, especially with regards not only to their strength but also to new performance concepts which are affordability, energy efficiency and environment friendly aspects. The study comprised mainly of laboratory tests of used materials and cost estimation analysis. Study results established that the considered bamboo and mud bricks, made in ordinary soils and reinforced by sisal fibers were reusable, environment friendly materials and energy efficient, with the bamboo showing the thermal conductivity equal to 0.1496 W/mK. Regarding the compressive strength, reinforced mud bricks with sisal fibers showed an increased value from 1.75 MPA to 4.29MPA, what was in line with related previous studies. The average compressive strength of the studied Arundinaria Alpine bamboo was established at 133,7MPA, while its tensile strength was 88.16MPA and these values were reasonable with comparison to other conventional materials. It is recommended that further research in checking the performance of other types of bamboo as well as about new construction technologies be undertaken in order to enhance the service life of both bamboo and mud bricks.Keywords: Affordability, Bamboo, Conventional concrete, Materials strength, Mud reinforced bricks, Sustainability

scholarly journals Geo-Environmental investigation of Sahure pyramid complex, Abusir Archeological site, Giza, Egypt

2021 ◽  
Author(s):  
Abdelrhman Muhamed Fahmy Sayed Ahmed ◽  
Fatma Muhamed Helmy
Keyword(s):  
Building Materials ◽  
Construction Materials ◽  
Polarized Light ◽  
Archaeological Site ◽  
Field Studies ◽  
Point Of View ◽  
Western Side ◽  
The Impact ◽  
Archeological Site ◽  
Engineering Stability

Abstract Abusir is the name of an elaborate burial area, dotted with 19 pyramids other temples, stretching on the western side of the Nile from the south of the Giza Plateau to the northern rim of Saqqara. It seems to have been created as the resting site for the Pharaos dated from 2494 to 2345 BC. The name Abusir, originally spoken as Busiri, means” temple of Osiris”. Over time, the name has become so popular, that more than 60 villages now carry this name. But only one is the archaeological site. This paper does not refer to all of the Abusir archaeological area, but focuses one of its most important sites: Sahure pyramid, one of Egypt’s little known, but heavily damaged treasure. One of the highlights of the relevant research is the discovery of a piece of cement (Basaltic mortar/concrete), which consists of several materials and which is harder than any cement produced today and detection of a clear and significant Anorthite mineral (Plagioclase) in the mortar sample which had been proven by XRD, XRF (analysis) and Polarized light microscope (investigation). The main objectives of this paper are 1) to reveal and identify the construction materials of the pyramid and the construction of the pyramid,2) to evaluate the durability and vulnerability of the Ancient construction materials of Sahure pyramid,3) to compare the decayed patterns of the different construction materials, 4) to study the pyramid building materials from geological, meteorological, geochemical, petrological and petrophysical point of view, and 5) to present a proposal for scientific conservation and protection of the pyramid. Laboratories and field studies have been carried out by researchers from various countries to investigate and understand the problems of the pyramid leading to the final results which confirmed the impact of the geo environment conditions on the structural and engineering stability of the pyramid.

scholarly journals OMI satellite observations of decadal changes in ground-level sulfur dioxide over North America

2017 ◽  
Vol 17 (9) ◽  
pp. 5921-5929 ◽  
Author(s):  
Shailesh K. Kharol ◽  
Chris A. McLinden ◽  
Christopher E. Sioris ◽  
Mark W. Shephard ◽  
Vitali Fioletov ◽  
...  
Keyword(s):  
Air Quality ◽  
North America ◽  
Sulfur Dioxide ◽  
Power Plants ◽  
Ground Level ◽  
In Situ Measurements ◽  
Ozone Monitoring Instrument ◽  
Control Laws ◽  
The Impact

Abstract. Sulfur dioxide (SO2) has a significant impact on the environment and human health. We estimated ground-level sulfur dioxide (SO2) concentrations from the Ozone Monitoring Instrument (OMI) using SO2 profiles from the Global Environmental Multi-scale – Modelling Air quality and CHemistry (GEM-MACH) model over North America for the period of 2005–2015. OMI-derived ground-level SO2 concentrations (r = 0. 61) and trends (r = 0. 74) correlated well with coincident in situ measurements from air quality networks over North America. We found a strong decreasing trend in coincidently sampled ground-level SO2 from OMI (−81 ± 19 %) and in situ measurements (−86 ± 13 %) over the eastern US for the period of 2005–2015, which reflects the implementation of stricter pollution control laws, including flue-gas desulfurization (FGD) devices in power plants. The spatially and temporally contiguous OMI-derived ground-level SO2 concentrations can be used to assess the impact of long-term exposure to SO2 on the health of humans and the environment.

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