Biological susceptibility of earth plasters: The influence of relative humidity on fungal growth

All building materials can be affected by microbiological agents during their lifecycle. The presence of microorganisms changes the appearance of the surface, degrading it, and they can even cause health problems to the residents. The biological susceptibility is dependent on the content of nutrient based on organic compounds. Thus one of the most susceptible of those materials are earthen construction materials. The degree of fungal growth is influenced by the chemical composition and plant fibres additives as well as the external conditions such as temperature and relative humidity. The earth plastering mortar has started to gain more attention recently as it is considered to have a low environmental impact and to increase the indoor air quality. Mechanical and physical characteristics of earth materials were studied by a number of authors but the knowledge about the biological resistance of the material is scarce. This study intends to look into the issue of the biological colonisation of earth plasters depending on the relative humidity. The samples, made of four types of earth plasters with different plant fibres, were placed to an environment of the relative humidity ranging from 33% to 100%. During a period of 4 weeks the extent of fungal growth was observed.

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Indoor air quality of newly built low-energy preschools – Are chemical emissions reduced in houses with eco-labelled building materials?

Indoor and Built Environment ◽

10.1177/1420326x18792600 ◽

2018 ◽

Vol 28 (4) ◽

pp. 506-519 ◽

Cited By ~ 4

Author(s):

Josefin Persson ◽

Thanh Wang ◽

Jessika Hagberg

Keyword(s):

Air Quality ◽

Relative Humidity ◽

Indoor Air Quality ◽

Air Temperature ◽

Indoor Air ◽

Building Materials ◽

Ventilation System ◽

Sampling Period ◽

Low Energy ◽

Low Energy Buildings

The use of an airtight frame in low-energy buildings could increase the risk of health-related problems, such as allergies and sick building syndromes (SBS), associated with chemical emissions from building materials, especially if the ventilation system is not functioning properly. In this study, the indoor air quality (IAQ) was investigated in newly built low-energy and conventional preschools by monitoring the indoor air temperature, relative humidity, particle-size distribution and levels of carbon dioxide (CO2), nitrogen dioxide (NO2), formaldehyde and total volatile organic compounds (TVOC). The thermal comfort was satisfactory in all preschools, with average indoor air temperature and a relative humidity at 21.4°C and 36%, respectively. The highest levels of TVOC (range: 130–1650 µg/m3 toluene equivalents) and formaldehyde (range: 1.9–28.8 µg/m3) occurred during the first sampling period associated with strong emissions from building materials. However, those preschools constructed with environmental friendly building materials (such as Swan Eco-label) had lower initial TVOC levels compared to those preschools constructed with conventional building materials. The IAQ and indoor chemical emissions were also strongly dependent on the functioning of the ventilation system. Preliminary risk assessment indicated that exposure to acrolein and crotonaldehyde might lead to respiratory-tract irritation among occupants.

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Primary and Secondary Emissions of VOCs and PAHs in Indoor Air from a Waterproof Coal-Tar Membrane: Diagnosis and Remediation

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph182312855 ◽

2021 ◽

Vol 18 (23) ◽

pp. 12855

Author(s):

Rafael Piñeiro ◽

Eva Jimenez-Relinque ◽

Roman Nevshupa ◽

Marta Castellote

Keyword(s):

Organic Compounds ◽

Indoor Air ◽

Building Materials ◽

Coal Tar ◽

Ventilation System ◽

Construction Materials ◽

Residential Building ◽

Secondary Emission ◽

Volatile Organic ◽

Organic Halogens

Primary and secondary emissions of volatile organic compounds (VOCs) and polycyclic aromatic hydrocarbons (PAHs) from a waterproof coal tar membrane and their effect on the indoor air quality were investigated through a case study in a residential building situated in Madrid, Spain. The air contaminants were analyzed in situ using photoionization method and several samples of contaminants were taken using three sorbents: activated carbon, XAD2 and Tenax GR. It was found that various VOCs such as toluene, p- and m-Xylene, PAHs such as naphthalene, methyl-naphthalenes, acenaphthene, acenaphthylene, phenanthrene and fluorine, volatile organic halogens including chloroform and trichlorofluoromethane, and alkylbenzene (1,2,4-trimethylbenzene) were found at concentrations, which exceeded the limits established by international and national agencies (WHO, EPA, OSHA). Some of the above organic compounds were found also in the samples of construction and building materials, which were obtained at different heights and places. The analysis of possible sources of the contaminants pointed at the original coal-tar membrane, which was applied on the terrace to be waterproof. During a posterior reparation the membrane was coated with a new one that hindered dissipation of emitted contaminants. The contaminants leached out and were absorbed by construction materials down in the dwelling. These materials then acted as secondary emission sources. To remediate the emission problem as the contaminated materials were removed and then a ventilation system was installed to force the gasses being emitted from the rest of contaminated slab outside. Follow-up has validated the success of the remediation procedure.

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Indoor air quality in an Antarctic Research Station: Fungi, particles and aldehyde concentrations associated with building materials and architectural design

Indoor and Built Environment ◽

10.1177/1420326x17719953 ◽

2017 ◽

Vol 27 (10) ◽

pp. 1322-1340

Author(s):

Érica Coelho Pagel ◽

Neyval Costa Reis ◽

Cristina Engel de Alvarez ◽

Jane Méri Santos ◽

Sandra Paule Beghi ◽

...

Keyword(s):

Air Quality ◽

Indoor Air Quality ◽

Indoor Air ◽

Architectural Design ◽

Building Materials ◽

Fine Particles ◽

Sampling Site ◽

Construction Materials ◽

Waste Incineration ◽

Research Station

Antarctic buildings are enclosed structures, which provide shelter and logistic support to researchers and personnel who remain indoors for long periods and can be affected by air pollution caused by construction materials and activities inside buildings. This study aims to investigate the indoor air quality at the Brazilian Comandante Ferraz Antarctic Station based on measurements of aldehydes, particulate matter and fungi conducted during the Antarctic summer in 2012. The sampling site was divided in conditioned (personnel living quarters) and unconditioned (service and utilities areas) compartments and outdoor sites. A field log book was used to record the activities in the station. Furniture and plywood coverings may have contributed to high average concentrations of formaldehyde. Cooking resulted in high average levels of acrolein and fine particles in most of the monitored environments. Other activities such as cleaning, use of personal and cosmetic products, waste incineration, building maintenance and movement of people and vehicles have also contributed to particles concentration increase. Dominance of the species Aspergillus versicolor and Penicillium sp. showed potential means of fungal proliferation. Considering that the functionality and operation are similar in many Antarctic buildings, some general recommendations were outlined.

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INTEGRATING EARTHEN BUILDING MATERIALS AND METHODS INTO MAINSTREAM CONSTRUCTION

Journal of Green Building ◽

10.3992/1943-4618.15.1.87 ◽

2020 ◽

Vol 15 (1) ◽

pp. 87-106

Author(s):

Lola Ben-Alon ◽

Vivian Loftness ◽

Kent A Harries ◽

Erica Cochran Hameen ◽

Michael Bridges

Keyword(s):

Indoor Air ◽

Building Materials ◽

Decision Makers ◽

Environmental Assessments ◽

Technical Data ◽

Building Permits ◽

Earthen Construction ◽

Survey Responses ◽

Depth Interviews ◽

Building Policy

ABSTRACT Earthen Building Materials and Methods (EBMM) exhibit excellent environmental, health, indoor air quality and affordability benefits. Despite these advantages, EBMM are not yet broadly implemented in mainstream construction. The main barriers and gaps to implementing earthen construction are analyzed through 126 survey responses and 10 in-depth interviews of a range of experts and end-users, and possible solutions to overcoming these barriers are presented. Specifically, the research indicates that according to earthen construction experts and potential homeowners, inability or difficulty in obtaining building permits is the strongest barrier to implementation. Additionally, existing technical data and environmental assessments must be synthesized and enumerated in order to support decision makers in advancing earthen building policy.

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ASSESSMENT OF THE INDOOR AIR PURIFICATION BY PHOTOCATALYTIC PAINTS

Latin American Applied Research - An international journal ◽

10.52292/j.laar.2020.352 ◽

2020 ◽

Vol 50 (2) ◽

pp. 71-76

Author(s):

Federico Salvadores ◽

Orlando Mario Alfano ◽

María de los Milagros Ballari

Keyword(s):

Indoor Air ◽

Photocatalytic Oxidation ◽

Building Materials ◽

Photocatalytic Performance ◽

Construction Materials ◽

Heterogeneous Photocatalysis ◽

Air Purification ◽

Air Flow Rate ◽

Carbon Doped ◽

Indoor Conditions

Photocatalytic building materials containing TiO2 were extensively studied for outdoor applications using solar radiation. Nowadays, the market offers a wide variety of these materials with self-cleaning and air purification functionalities. However, heterogeneous photocatalysis applied in indoor construction materials was less developed. The objective of this work is to investigate the photocatalytic performance of carbon doped TiO2 in replacement of the normal pigments in indoor wall paint formulations. To achieve this goal, the photocatalytic oxidation of acetaldehyde in gas phase was carried out. The air decontamination process was conducted using regular indoor light in a bench scale chamber photoreactor simulating a room. The main environmental conditions that affect the photocatalytic process were varied: air flow rate, irradiance, relative humidity and acetaldehyde concentration. The results were analyzed through the response surface methodology and revealed the air purifying power of photocatalytic paints under indoor conditions.

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Influence of Biopolymers on the Mechanical Behavior of Earth-Based Building Materials

Recent Progress in Materials ◽

10.21926/rpm.2103031 ◽

2021 ◽

Vol 03 (03) ◽

pp. 1-1

Author(s):

Julia Tourtelot ◽

◽

Ann Bourgès ◽

Emmanuel Keita ◽

◽

...

Keyword(s):

Compressive Strength ◽

Building Materials ◽

Construction Materials ◽

Wheat Starch ◽

Low Carbon ◽

Food Industries ◽

The Earth ◽

Construction Techniques ◽

Paris Region ◽

Raw Earth

Currently, the largest among the earth excavation sites in Europe are located in the Paris region. The soils excavated from these sites are often considered waste and are not valorized. With an increasing focus on sustainable development, the demand for low-carbon building materials is rising. Although construction using raw earth is a vernacular technique, the diversity in the behavior of the raw earth building materials warrants better control of their mechanical properties. The construction techniques differ depending on the location of the site, the composition of the earth, and the stabilizers used. Plant-based fibers and compounds extracted from plants are commonly used for reinforcing raw earth. Since such byproduct solutions have been developed worldwide, they differ significantly, and it becomes difficult to set a benchmark. The majority of the reported studies have directly used organic waste, rendering it difficult to characterize the material and extend the obtained results to other contexts. In order to reduce these variabilities, it becomes important to study the reinforcement of earth-based building materials with biopolymers that constitute the active molecules of the bio-based solutions. In the present study, different biopolymers derived from various vernacular techniques were utilized to increase the compressive strength of the construction soil collected from the Paris region. It was revealed that cellulose fibers and wheat starch increased the compressive strength of the earth from 3.5 MPa to 5.5 MPa and 4.5 MPa, respectively. In addition, the interactions of these biopolymers with clay were analyzed. The biopolymers identified as suitable for use in construction materials in the present study are widely available as wastes from paper, agricultural, or agro-food industries. These identified biopolymers would contribute to the development and standardization of construction using earth-based building materials.

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An overview of the remaining challenges of the RILEM TC 274-TCE, testing and characterisation of earth-based building materials and elements

RILEM Technical Letters ◽

10.21809/rilemtechlett.2021.149 ◽

2022 ◽

Vol 6 ◽

pp. 150-157

Author(s):

Antonin Fabbri ◽

Jean Claude Morel ◽

Jean-Emmanuel Aubert ◽

Quoc-Bao Bui ◽

Domenico Gallipoli ◽

...

Keyword(s):

Building Materials ◽

Construction Materials ◽

Holistic Approach ◽

Technical Committee ◽

Rilem Technical Committee ◽

Approach Coping ◽

Earthen Construction ◽

Important Challenge ◽

Earthen Architecture ◽

Ecological Transition

Based on the RILEM Technical Committee 274-TCE work, this paper is a discussion of the remaining engineering challenges faced by earthen architecture. The assessment of earth material performances requires the development of appropriate procedures and standards. This is discussed in particular for the characterisation, hygrothermal behaviour, mechanical behaviour, and durability of earth materials. One other important challenge, since one of the main advantages classically put forward, is its ecological performance, is a proper assessment of life cycle assessment of earth materials, elements and buildings. Moreover, the paper develops why the approach to earthen construction must be different compared to the dominant construction materials, to preserve its ability to contribute to the ecological transition in the construction sector. In particular, the needs of using local soils, with an architectural approach coping with the limits of the materials, and developing an architectural optimisation to preserve the earthen materials multifunctionality rather than selecting a sole property to be maximised. Lastly, the findings of the paper can be used to develop a holistic approach to earthen construction to foster the development of new earthen architecture projects.

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Mortars with Recycled Aggregates from Building-Related Processes: A ‘Four-Step’ Methodological Proposal for a Review

Sustainability ◽

10.3390/su13052756 ◽

2021 ◽

Vol 13 (5) ◽

pp. 2756

Author(s):

Federica Vitale ◽

Maurizio Nicolella

Keyword(s):

Building Materials ◽

Thermal Analyses ◽

Construction Materials ◽

Physical And Mechanical Properties ◽

Research Trends ◽

Mix Design ◽

Recycled Aggregates ◽

Design Parameters ◽

Natural Aggregates ◽

By Products

Because the production of aggregates for mortar and concrete is no longer sustainable, many attempts have been made to replace natural aggregates (NA) with recycled aggregates (RA) sourced from factories, recycling centers, and human activities such as construction and demolition works (C&D). This article reviews papers concerning mortars with fine RA from C&D debris, and from the by-products of the manufacturing and recycling processes of building materials. A four-step methodology based on searching, screening, clustering, and summarizing was proposed. The clustering variables were the type of aggregate, mix design parameters, tested properties, patents, and availability on the market. The number and the type of the clustering variables of each paper were analysed and compared. The results showed that the mortars were mainly characterized through their physical and mechanical properties, whereas few durability and thermal analyses were carried out. Moreover, few fine RA were sourced from the production waste of construction materials. Finally, there were no patents or products available on the market. The outcomes presented in this paper underlined the research trends that are useful to improve the knowledge on the suitability of fine RA from building-related processes in mortars.

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Application of Plastic Wastes in Construction Materials: A Review Using the Concept of Life-Cycle Assessment in the Context of Recent Research for Future Perspectives

Materials ◽

10.3390/ma14133549 ◽

2021 ◽

Vol 14 (13) ◽

pp. 3549

Author(s):

Tulane Rodrigues da Silva ◽

Afonso Rangel Garcez de Azevedo ◽

Daiane Cecchin ◽

Markssuel Teixeira Marvila ◽

Mugahed Amran ◽

...

Keyword(s):

Life Cycle Assessment ◽

Life Cycle ◽

Solid Waste ◽

Building Materials ◽

Construction Materials ◽

Plastic Waste ◽

Plastic Wastes ◽

Solid Waste Generation ◽

Alternative Processes

The urbanization process contributes to the growth of solid waste generation and causes an increase in environmental impacts and failures in the management of solid waste. The number of dumps is a concern due to the limited implementation and safe disposal of this waste. The interest in sustainable techniques has been growing in relation to waste management, which is largely absorbed by the civil construction sector. This work aimed to review plastic waste, especially polyethylene terephthalate (PET), that can be incorporated with construction materials, such as concrete, mortars, asphalt mixtures, and paving. The use of life-cycle assessment (LCA) is related, as a tool that allows the sustainability of products and processes to be enhanced in the long term. After analyzing the recent literature, it was identified that studies related to plastic wastes in construction materials concentrate sustainability around the alternative destination of waste. Since the plastic waste from different production chains are obtained, it was possible to affirm the need for a broader assessment, such as the LCA, providing greater quantification of data making the alternative processes and products more sustainable. The study contributes to enhance sustainability in alternative building materials through LCA.

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