bluuebunny/crossref_metadata_2025 huggingface dataset:
Physical, Thermal and Microstructural Characterization of Earth Mortars Stabilized with Incorporating Air Additive
Authors: Paiva Rayane de Lima Moura , Sousa Patrícia Brandão , Carreira Camila de Barros Lima , Martins Adriana Paiva Souza , Toledo Filho Romildo Dias
Published: January 2022

In recent years, the search for non-conventional materials has intensified, aiming to reduce environmental impacts in the civil construction sector as a strategy for more sustainable development. Among these materials, earth mortars are a promising option, as they have technological, economic, and environmental advantages. Due to the absence of literary data on the use of air-incorporating additives (AEA) in earth mortars, the objective of this article is to verify the influence of the incorporation of AEA (0,10, 20, and 40% of the total volume of the mixture) in the mechanical properties (compression strength at 28 days), physical (total water absorption by immersion), thermal, and microstructural (scanning electron microscopy) of the referred mortars. The study was carried out in a stabilized earth mortar, with a 1:3 mass mix proportion (binder: aggregate). The raw materials used were constituted by binders (cement, hydrated lime, fly ash, metakaolinite), aggregates (sand, a coarse fraction of the soil), additives (AEA, calcium chloride, superplasticizer), and water. The water-binder material ratio (a / bm) was fixed at 0.65, and the consumption of binder and aggregate was 461.71 and 1385.12 kg, respectively, per m3 of the mixture. The tests demonstrated that the incorporation of the additive influenced the behavior under compression (strength and stiffness reduction), thermal performance (conductivity reduction), and physical behavior (absorption and voids index´s increases) compared to the mixture without AEA. From the analysis of the results, it was found that the incorporation of air in the mortars led to an increase in porosity, directly influencing the thermal insulation capacity, measured by thermal conductivity. Microstructure changes were observed through SEM images, corroborating the influence of the AEA. Under compression loads, the stiffness reduction decreases the risk of eventual cracking, however, the reduction in strength should be controlled to meet normative limits.
Mechanical Compression and Crushing Properties of a Straw-Lime Material
Authors: Parmo Parmo , Hanus Jean-Luc , Belayachi Naima , Bailly Patrice
Published: January 2022

The aim of this study was to determine the compressive mechanical properties and the energy absorption characteristics of a bio-composite material based on lime, wheat straw, and additives (protein and entraining agent). The selected samples with fiber to binder ratio of 30% were subjected to compression tests at different strain rates (1 mm/min, 10 mm/min, and 100 mm/min), in the perpendicular and parallel directions to fiber orientation. Image analysis supported with Digital Image Correlation (DIC) method is performed to follow longitudinal and lateral deformations, thus making it possible to evaluate elastic properties. The results show that the highest density and compressive strength in the parallel direction are ~349 kg/m3 and ~0.101 MPa, respectively. The perpendicular specimens at 100 mm/min of speed test showed the highest values of densification strain, stress plateau, energy efficiency, and absorbed-energy of 47.27%, 0.32 MPa, 16.98 %, and 13.84 kJ/m2, respectively. The values of Young’s modulus identified with DIC are significantly different from those determined by the slope of the linear part of the stress-strain curve. A slight influence of strain rate on mechanical properties is observed.
Evaluation of a Marine Dredged Sediment as Raw Material Compared to Volcanic Scoria for the Development of Lime-Pozzolan Eco-Binders
Authors: KOURTAA Salim , Chabannes Morgan , Becquart Frederic , Abriak Nor Edine
Published: January 2022

In the context of global warming, the built environment offers relevant opportunities to reduce GHG emissions that underlie climate change. In particular, this can be achieved with the development of low-embodied energy building materials such as bio-based concretes. Hemp concrete has been the subject of many investigations in the field of non-load bearing infill walls in France since the early 1990s. In addition to hygrothermal performances, the use of crop by-products definitely helps to limit the carbon footprint. Hemp concretes are often produced by mixing the plant aggregates with lime-based binders. The latter have many benefits among which the water vapor permeability. However, CO2 emissions due to the decarbonation of limestone for the production of lime largely contribute to the overall environmental balance of these materials. The use of natural pozzolans (volcanic scoria) combined with hydrated lime goes back to the Greco-Roman period and reduces carbon emissions. Nonetheless, it does not necessarily meet the issue related to the depletion of granular natural resources. Hence, this study deals with the design of a new low-carbon binder based on marine dredged sediment seen as an alternative strategic granular resource that can be considered renewable. The sediment comes from the Port of Dunkirk in the North of France and is mainly composed of silt and quartz sand. It was finely ground and compared to a lowly reactive basaltic pozzolan. Lime-pozzolan pastes were prepared and stored in a moist environment under room (20°C) and high temperature (50°C). The hardening kinetics of pastes was followed through mineralogical studies (TGA, XRD) and compressive strength development. The results showed that the hardening of pastes including the marine sediment was suitable in the case of samples stored at 50°C and make it possible to use such a binder for precast bio-based concretes.
Research for Substantiation to Upscale Bio-Based Materials in the Construction Industry
Authors: van der Burgh Fred , Verspeek Sissy
Published: January 2022

The building construction industry is slowly adopting bio-based materials. To accelerate this process, it is necessary to gain more proven data about technical issues. This should also fit in the social-economical and juridical context of the construction industry. In this paper we will highlight the main drivers and research that is going on in the Netherlands. Including a cross border project that works on this topic.
Properties of Phragmites australis for Insulating Concrete Application
Authors: Honoré Mathilde , Lecompte Thibaut , Pimbert Sylvie
Published: January 2022

The common reed, Phragmites australis, is a plant species quite similar to the currently used bio-based aggregates and available on most continents. The purpose of this work is to characterise this common reed and compare its properties to other plants already studied for building use. This study presents the different properties focussing on Phragmites australis chemical composition, hydrophobicity nature and how this character could be explained. To that end, wettability and also water adsorption measurements were carried out on plant flour and aggregates in comparison to miscanthus, wood and hemp shiv properties. Formulations based on reeds of different origins and using different binders (lime and earth) were tested in compression and with thermal conductivity measurements in order to evaluate the behaviour of the reed as a material for building use.
Self-Desiccation of a Vernacular CSA Binder
Authors: Martins Natalia Pires , Cicek Burhan , Brumaud Coralie , Habert Guillaume
Published: January 2022

The fast precipitation of ettringite in conventional Calcium Sulfo Aluminate (CSA) cement causes rapid stiffening of the cement paste and is directly associated with short setting times and self-desiccation. To extend the time during which those types of cement remain workable, retarding admixtures can be used. However, retarders may affect the amounts and types of hydration products formed and as a consequence the ability of hydrated cement to chemically bind water. This work investigates the influence of two natural-based admixtures on the self-desiccation ability of a vernacular CSA ternary binder used as earth stabilization. Vicat measurements were used to study the efficiency of citric acid and sucrose as retarding admixtures on the setting time of stabilized earth. A quantitative study of the self-desiccation ability of the binder was performed on dried binder pastes using thermogravimetric analysis (TGA). Results show that both admixtures have a significant impact on the setting time of the binder. Furthermore, TGA showed that the self-desiccation ability of this vernacular CSA binder is significantly reduced when citric acid at high dosages is used, both at early hydration and after 14 days. On the contrary, the use of sucrose does not affect the water chemically bound at an early age but can maximize bound water after 14 days of hydration.
Analyse of the Evolution of the Hygrothermal Properties of the Hemp-Based Mortar within the Framework of the Total Weathering Protocol
Authors: Kosiachevskyi Dmytro , Abahri Kamilia , Daubresse Anne , Prat Evelyne , Chaouche Mohend
Published: January 2022

The use of bio-based composites for building insulation is interesting from the point of view of hygrothermal performances, economic and environmental benefits. Among different organic fibers for these materials, hemp is interesting because of its huge availability in France. Nevertheless, the broad application of the hemp-based insulation mortars is hampered due to the lack of a database on their durability. This paper consists of a better understanding of the evolution of the hemp-based composite and its hygrothermal properties. The main objectives are, first, to study the evolution of the hemp insulation mortar microstructure and properties under the accelerated aging cycles, and second, to characterize and analyze the interconnection between observed changes. Experimentally, the protocol of accelerated aging inspired by standardized one was proposed, the microstructural characteristics and the hygrothermal properties, as the total porosity, the thermal conductivity, and the moisture buffer value (MBV) before and after the aging cycles was identified. The MBV characterization was performed for both hemp mortar and hemp shives. The obtained results reveal the increase of the hemp mortar porosity and the decrease of the hemp mortar's thermal conductivity. Furthermore, the MBV value of hemp mortar changes slightly, unlike that of the bulk hemp, which is explained by the mineral matrix's influence. These results consist of data for a better forecast on the degradation of the hemp mortar.
Customising Microstructural and Mineralogical Characteristics of Hydrated Lime Using Biopolymers
Authors: Pesce Cecilia , Pesce Giovanni , Molinari Marco , Richardson Alan
Published: January 2022

The study of lime-based systems is vital to the design of new sustainable building materials. Air lime (calcium hydroxide, Ca (OH)2) is a binder that has attracted considerable attention for its ability to capture CO2 from the atmosphere, its low-cost and low-energy production process. Furthermore, Ca (OH)2 is an important phase of hydrated Portland cements, and lime-based mortars have shown high elasticity and the ability of self-healing. The performance of lime-based building materials can be enhanced by the addition of organic compounds that can modify the mineralogy and microstructure of Ca (OH)2. In this study, the effects of four biopolymers including starch, inulin, pectin, and calcium lignosulfonate, on the microstructure and mineralogy of lime have been investigated. Hydrated lime was produced by slaking quicklime in water. Two sets of hydrated lime batches were produced for each polymer: (i) the polymer was previously dissolved in water and subsequently mixed with lime, and (ii) the polymer was added as a dry powder to the already hydrated lime at the end of the slaking process. Characterisation of the batches was performed using scanning electron microscopy, X-ray diffraction and laser diffraction. Results indicate that biopolymers affect the nucleation and growth of Ca (OH)2 crystals. This influences the microstructure and crystal aggregation of hydrated lime in colloidal suspension, which will have important implications on the use of biopolymers in Portland cement applications and in the use of lime as a binder for mortars.
Microstructural Characterization of Prefabricated Hempcrete Blocks
Authors: Moletti Chiara , Arosio Valeria , Dotelli Giovanni
Published: January 2022

Sustainable building materials have been developed to reduce the polluting emissions and the exploitation of natural resources of the building sector. Among these materials, an outstanding category is that of nature-based solutions which are produced recovering waste or by-products of agricultural cultivations and using them as vegetal aggregates to replace the traditional ones. This paper focusses on hempcrete which is produced mixing the by-product of industrial hemp cultivation (i.e., shives) and lime to obtain a sustainable, breathable and insulating material. The strength of hempcrete develops through carbonation of the binder that, leading to the formation of calcium or magnesium carbonates and mineralization of shives, determines the microstructure and hence most of the characteristic properties of the material. The aim of this research is to investigate how carbonation influences the microstructure of hempcrete when different recipes are used for blocks production. This study consists in the characterization of the material through techniques such as XRD (X-ray Diffractometry), SEM (Scanning Electron Microscopy) and TG-DTG (thermogravimetric analyses). Moreover, the evolution of carbonation is studied analyzing samples at different maturation times. The investigation of the carbonation reaction degree is also crucial to evaluate the environmental performances of the material because it allows the quantification of the carbon dioxide uptake. Also, periodic characterization allows to assess the durability of hempcrete and to select the best formulation according to the designed application and the corresponding service conditions.
Improved Magnesium Cement for Durable Hemp Composite Boards
Authors: Zorica Jelizaveta , Sinka Maris , Sahmenko Genadijs , Bajare Diana
Published: January 2022

Hemp concrete is a well-known bio-based building material, but due to its relatively low compressive strength is mainly used as an insulation material with a load-bearing wooden frame. There are possibilities to expand hemp concrete application in construction by substituting traditional lime with magnesium cement. Magnesium oxychloride cement is a material already known for some time and nowadays used in building board production. Strength, lightweight, ease of use are advantages that highlight relatively new magnesium oxychloride type boards compared to traditional sheeting materials such as plywood, gypsum plasterboard and fibre-cement board. Therefore, similar parameters are thought to be reached by producing magnesium oxychloride hemp board. In this work, magnesium cement water resistance was studied and possibilities to improve it was examined by adding fly ash and nanosilica. Among the nanomaterials used in building materials, nanosilica has gained significant interest by performing a beneficial effect in improving the mechanical properties of concretes. In addition, due to its ultrafine size and high chemical reactivity, the performance of nanosilica is much better with a lower amount of admixture required. Results show that applied nanosilica slightly reduced the compressive strength of magnesium cement in a dry state, but at the same time significantly increased its water resistance. Hemp magnesium oxychloride cement board prototype samples were produced and demonstrate promising results for further manufacturing of hemp composite boards.
Micro-Macro Modelling Approach of Vegetal Wools Thermal Conductivity
Authors: Piégay Clément , Glé Philippe , Gourlay Etienne , Gourdon Emmanuel , Marceau Sandrine
Published: January 2022

Biosourced materials such as vegetal wools offer major thermal insulation advantages in the green buildings field. Experimental characterisations of vegetal wools thermal conductivity as a function of their density show the existence of an optimum conduction-radiation coupled value. This specific point, as well as the properties of vegetal wools are related to the large variability of shapes and sizes of their fibres. In order to take this specificity into account, it seems particularly relevant to use micro-macro modelling methods to predict the thermal conductivities related to both conduction and radiation heat transfer phenomena. In a first time, a self-consistent method based on a cylindrical geometry (SCMcyl) is used as a modelling approach for conduction transfers. Then, a modelling approach developed by Bankvall and based on an equivalent fibre radius value is used for radiation transfers. So, by coupling these two approaches, it is possible to obtain an equivalent thermal conductivity of fibrous materials as a function of density. Finally, this method is validated by comparison with experimental data.
Thermal Insulation Blocks Made of Sunflower Pith Particles and Polysaccharide-Based Binders: Influence of Binder Type and Content on Their Characteristics
Authors: Laborel-Préneron Aurélie , Ampe Clara , Labonne Laurent , Magniont Camille , Evon Philippe
Published: January 2022

Co-product of sunflower cultivation, pith of stem has a little exploited insulating potential. Blocks in which pith particles are glued together using a starch-based binder have already been obtained. However, they are highly water-sensitive. Replacing this binder with others has been considered here. Polysaccharide-based binders were tested, chosen for their more hydrophobic character: sodium alginate, chitosan, Citrus pectin, and a modified starch. Like starch, these binders are physically binding. They are first solubilised in water (except chitosan, dissolved in 2% acetic acid). The solution is then mixed with pith particles before cold compression molding for 90 s. A 10% binder content was initially considered. The blocks were all cohesive with a dry density from 36 to 42 kg/m3). Their performances were assessed through water absorption capacity and resistance via capillary absorption tests on wet sponges, mechanical test and thermal conductivity. Chitosan and pectin-based blocks show the best properties, particularly concerning water resistance and mechanical properties. The pectin-based block has improved its elastic modulus by 40% compared to a starch-based block. The pectin-based block in its case absorbs 2.7 times less water than starch. Finally, thermal conductivities of pectin and chitosan-based pith blocks are in the same order of magnitude as for starch (39.8-40.1 mW/m.K), and close to values from commercial materials (e.g., polystyrene). Pectin and chitosan were also tested at three rates (5%, 10% and 15%). A significant improvement in the blocks' compressive strength was observed with the increase in binder rate, while thermal conductivities varied little.
Life Cycle Assessment of a Wall Made of Prefabricated Hempcrete Blocks
Authors: Arosio Valeria , Moletti Chiara , Dotelli Giovanni
Published: January 2022

Hempcrete is a natural building material obtained mixing hemp shives (i.e., the woody core of the hemp plant) with a lime-based binder and water. Hempcrete as construction material is gaining increasing interest as the EU aims to achieve net zero emissions by 2050. This material has, in fact, the ability to uptake carbon dioxide from air (i.e., via carbonation) and to store carbon for long time. The goal of the present work is to deeper analyze the environmental profile of hempcrete, in order to assess its potentials in reducing emissions of construction sector. Specifically, Life Cycle Assessment (LCA) of a non-load-bearing wall made of hempcrete blocks is carried on. The analysis encompasses the whole life cycle from the extraction of raw materials to the end of the service life. The analyzed blocks are produced by an Italian company. Only aerial lime is used as binder, microorganisms are added to the blocks to accelerate carbonation. The impact on climate change is assessed through the GWP 100 method proposed by IPCC. Preliminary results reveal a nearly neutral carbon budget.
Starch Reinforcement of Raw Earth Constructions
Authors: Tourtelot Julia , Fourdrin Chloé , d'Espinose de Lacaillerie Jean Baptiste , Bourgès Ann , Keita Emmanuel
Published: January 2022

The restoration, the protection, or the creation of earthen buildings require improving the mechanical strength of the material. The first way to do that is to use inorganic additives, but these additives change the structural properties of earth and have a high carbon footprint. In contrast, the other way to consolidate is the use of organic additives such as vegetal derivatives that rearrange the minerals in the earth, with the lowest carbon footprint as they are from waste management. After preliminary tests with ten different organic additives from traditional recipes, we found that wheat starch improves the earth strength up to 50 %. In this study, we related the mechanical strengthening to the physicochemical interactions between clays and starch. We focus on three clays that represent the three main groups of clays: kaolinite, illite and montmorillonite. For this study, we mainly focused on compressive test and rheological tests. We showed that the improvement of the mechanical strength with starch is depending on clay nature and their chemistry. Then, we can recommend formulations based on the earth nature for new sustainable buildings. Furthermore, we can understand why it was an interesting way to use starch as a strengthening agent in traditional recipes and how it could be used to repair and protect buildings made of earthen material.
Earth Plastered Wall Heating as a Low-Emitting, Cost-Effective and Robust Energy System for Building Renovation
Authors: Galimshina Alina , Moustapha Maliki , Hollberg Alexander , Wagner Guy , Padey Pierryves , Lasvaux Sébastien , Sudret Bruno , Habert Guillaume
Published: January 2022

Renovation of the building stock in Europe is urgent to decrease the environmental impact from the building sector and meet the United Nations climate action goals. However, it is often hard to define a robust scenario for a renovation due to numerous uncertainties, which occur during the production, operation and end-of-life stage. One can cite the loss of performance of insulation and heating systems, the replacement time of installation or the future energy prices as well as the future climate. The replacement of oil boilers with heat pumps has shown a good performance regarding costs and greenhouse gas emissions. However, due to the flow and return temperature differences, often the current heat distribution system needs to be replaced as well, which is normally done with conventional radiators or floor heating. In this paper, we analyse a new possibility of a heat distribution system with earth plastered wall. We develop a methodology on the integrated assessment of life cycle assessment (LCA) and life cycle cost analysis (LCCA) for the renovation scenarios and adapt the analysis of the heat pump renovation solution with conventional radiators system and the earth plastered wall for two typical residential buildings located in Switzerland. Through rigorous statistical treatment, we then propagate the possible sources of uncertainty and perform the uncertainty quantification using polynomial chaos expansion to compare the distributions of two outcomes. The results show that the solution with the earth plaster has lower overall environmental impacts and costs. It has also been noticed that the solution with the earth plaster is more robust in investment cost and embodied emissions compared to the solution with the conventional radiators.
Rheology, Mechanical Performance and Penetrability through Flax Nonwoven Fabrics of Lime Pastes
Authors: Rakhsh Mahpour Ali , Ardanuy Monica , Ventura Heura , Rosell Joan Ramon , Claramunt Josep
Published: January 2022

The use of plant fibers as a reinforcement for fragile matrices could be an option to improve the sustainability of the construction materials. These reinforcements can be in different forms as short fibers, long fibers or woven or nonwoven fabrics. The mechanical performance of the composites is significantly related to the adhesion between the matrix and the fibers. In the case of nonwoven reinforcement, to get good adhesion, the penetration of the paste is a key point. That is why this study addresses the relationship between rheology, penetration through the nonwoven fabrics and the mechanical properties of various lime pastes with different contents of water and metakaolin (MK). The effect of the binder’s grinding is also evaluated. The results indicate that MK pastes with higher w/b ratios penetrate better into nonwovens, Grinding has a negative effect on penetrability despite improving the mechanical properties of the pastes.
Effect of Immersion/Freezing/Drying Cycles on the Hygrothermal and Mechanical Behaviour of Hemp Concrete
Authors: Benmahiddine Ferhat , Belarbi Rafik
Published: January 2022

Hemp concrete is one of the most used bio-based materials in the construction industry due to its hygrothermal behaviour and its low environmental footprint. This is mainly due to the complexity of the microstructure of these materials and their highly breathable nature. However, their use remains limited due to the lack of databases and guarantees regarding of the evolution of their functional properties over time. In this paper, experimental investigation has been performed to answer this problematic. The aim is to investigate the influence of accelerated aging on the properties of this material through a succession of immersion/freezing/drying cycles. Materials (aged and reference) were characterized at the same relative humidity state in order to be able to compare the results and to highlight the effect of ageing on the properties of hemp concrete. Results revealed a significant change in the microstructure of this material. As a consequence, this induced significant changes in its hygrothermal and mechanical properties. An increase of 40% in water vapour permeability and decrease of 57% in compressive strength were observed after aging (07 cycles of immersion/freezing/drying).
Contribution on the Use of Household Waste as Bio-Admixture
Authors: Bella Ilham Aguida , Bella Nabil , Asroun Aissa , Saddiki Sara
Published: January 2022

In the civil engineering field, the incorporation of chemical admixtures is now a practical technics' used for improving the properties of concrete, such as improved workability, decreasing the water demand, increasing strength, etc. However, chemical admixtures have some disadvantages such as environmental pollution during both their manufacture and their use, else, there are rare somewhere. Because of this background, bio-admixtures appear principally useful, due to their environmental effect and friendly properties, bio-admixtures are substances obtained from a biodegradable product also resulting from the methanisation. The objective of this research is the valorization of household waste used as a bio-admixture. Moreover studying its effect on cement path workability, start/end of the cement setting.
Organic Brick
Authors: Grassi Giulia , Erken Aikebaier , Paoletti Ingrid
Published: January 2022

Clay is one of the earliest known material used in construction, and the most widely used building material on the planet. Our ancestors have performed the tasks of mixing water with dust to make clay, then shaping it into bricks, bricks into buildings, and buildings into cities for more than ten thousand years. In recent years, 3D printing technology has become increasingly popular thanks to its ability to manufacture complex morphologies and to optimize physical and mechanical properties for specific applications. This study investigates customized 3D clay bricks as a new building material (building component) by employing resources that are eco-friendly, locally available, inexpensive, and driven from recycled sources or waste streams. In this experiment, four different fiber types have been investigated with different clay treatment. The specimens were fabricated in the laboratory and tested with unconfined compression loading. The strength and ductility of the clay specimens were then analyzed based on the experiment results. Several experiments have been conducted during the study for understanding the effects of different fibers when mixed with clay in order to identify which type of fibers and which size has the most effective influence on its compression strength. Furthermore, it has been tested also the water absorption of the 3D printed brick. A case study has been developed to show the actual potential of 3D printed clay bricks for a small housing complex. The project is located in a village near to Abuja, Nigeria, at a time of exponential population increase and associated lack of affordable housing. The 3D printed blocks embed a cooling function, thanks to their geometry and the presence of cooling pipes directly in the wall. The result is a highly flexible envelope, designed to be resilient and energy efficient.
Variability Assessment of the Compressive and Tensile Strength of Fibred Earthen Composites
Authors: Poullain Philippe , Barnaure Mircea , Bonnet Stéphanie
Published: January 2022

Earthen composites (rammed earth, cob, adobe, daub, CEB...) are experiencing renewed interest from builders due to the many advantages of these building materials, and in particular their eco-friendliness. Nevertheless, the widespreading of these materials, as certified materials and conforming to construction standards, comes against the lack of data concerning their mechanical properties. Indeed, the literature generally gives the average values of the properties without indicating the number of specimens tested neither the distribution of the data. Yet, the mean value of the compressive strength is not enough to assess the reliability of a given earthen composite to build a wall and it would be better to indicate the value of a defined percentile (characteristic value just like with concrete composites). The aim of this paper is to analyze the data about the mechanical properties (tensile and compressive strength) obtained on different formulations of cob including natural fibres or not. The tests performed allowed to determine the probability density function and the average values, the standard deviation and the percentiles, for the various properties.
Performance of Alfa Fibres in Cementitious Materials Exposed to Diverse Surface Treatments
Authors: Ajouguim Soukaina , Page Jonathan , Djelal Chafika , Waqif Mohamed , Saadi Latifa
Published: January 2022

Alfa plant presents a great ecological and socio-economic interest in the Maghreb countries. It is used in several fields of applications such as craft production and paper industry. However, a few research work has been realized on the valorisation of Alfa fibres in the construction sector. The main objective of this work is to develop an Alfa fibre-reinforced mortar with significant mechanical properties for the facade panel’s manufacturing. It was highlighted that Alfa fibres enhance the flexural strength of reinforced mortars. Therefore, a decrease in the flexural strength of the composite after 90 days of curing. In addition, the incorporation of Alfa fibres reduced the compressive strength of the composite. In this regard, to enhance the mechanical properties of the composite, various treatments were explored: alkaline treatment with sodium hydroxide, hydrothermal treatment by water boiling, and coating with sulfoaluminate cement. It was noted that the treatments could provide a partial elimination of the non-cellulosic components and enhance the Alfa fibre roughness. Raw and treated Alfa fibres were incorporated into cement mortars at different lengths of the (10 and 20 mm) with an addition ratio of 1 %vol.. Compared to untreated fibres, fibres treated chemically provide an improvement of 38 % of the flexural strength at 28 days for both fibres length. Unlike the coated fibres, the efficiency of treatment was noted at 90 days of curing. Otherwise, a slight increase in compressive strength was observed compared to the untreated fibres mortar. These results were approved by porosity accessible to water and calorimetric tests.
Reed as a Thermal Insulation Material: Experimental Characterisation of the Physical and Thermal Properties
Authors: Malheiro Raphaele , Ansolin Adriana , Guarnier Christiane , Fernandes Jorge , Cosentino Lívia , Silva Sandra , Mateus Ricardo
Published: January 2022

The building sector plays a significant role in reducing global energy use and carbon emissions. In the European Union (EU), the building stock represents 40% of total energy use and in which cooling and heating systems represent over 50%. Portugal is one of the EU countries where the consequences of energy poverty are most evident due to the families' financial inability to adequately climate their homes. The reasons are several, but they are mainly linked to buildings' poor passive thermal performance, resulting from inadequate adaptation to the climatic context and reduced thermal insulation. Thus, it is necessary to develop solutions to increase buildings’ thermal performance and reduce their potential environmental impact, which arises mainly from the significant use of active systems. In this sense, natural building materials are a promising solution, reducing energy use and carbon emissions related to buildings. This research studies the potential use of reed found in Portugal (Arundo donax) as a thermal insulation material. Its physical characterisation and the influence of geometry configuration on its thermal performance are evaluated. Its durability was studied too. Reed stalks were used to carry out the physical and durability tests. A reed board (150 x 150 mm) was built, and its thermal performance was tested in a hotbox. According to the results, the characteristics of reeds found in Portugal make it suitable to be used as a building material. Furthermore, regardless of the configuration studied, the reeds have a satisfactory thermal performance to be used as thermal insulation, under the requirements defined by Portuguese thermal regulation, Re ≥ 0.30 (m2.oC)/W. There is a trend to the mould growth in the reed, but only under favourable conditions. Additionally, considering the abundance of reed throughout the Portuguese territory, this is an eco-friendly and low-cost option that gathers all requirements to be more used in the construction market.
Physico-Chemical Characterization of the Electric Arc Furnace Slag (EAFS) of the Sonasid-Jorf Steelworks - Morocco
Authors: Hamama Ayoub , Harrami M. , Saadi M. , Assani A. , Diouri Adeljebbar
Published: January 2022

The steelmaking process results in the by-product formation of electric arc furnace slag (EAFS). Slag is recovered at two different stages of the steelmaking process, the first recovery is black and the second is white. The present research focuses on the composition differences between the two types of slag from SONASID-Jorf steel in Morocco. A granular separation of the black and white slag was carried out to monitor the chemical and mineralogical composition. XRD and Fourier Transform Infrared Spectroscopy are performed on the samples in this paper. The slags suggest good hydraulic binder properties. It would be useful for research in the field of building materials to correlate the results of the characterization of EAFS with other types of slag with the aim of improving the potential for partial replacement of cement in the matrix. The slag can also be used as binders in mixtures of bio-based building materials. The electric arc furnace slag (EAFS), exhibiting appropriate cementitious activity, can be utilized as mineral admixture in cement and concrete. Black and white slags are studied in this paper in order to determine their characteristics according to their granularity.
Influence of Palm Oil Fibers Length Variation on Mechanical Properties of Reinforced Crude Bricks
Authors: Hussain Mazhar , Levacher Daniel , Leblanc Nathalie , Zmamou Hafida , Maigre Irini Djeran , Razakamanantsoa Andry
Published: January 2022

Crude bricks are composite materials manufactured with sediments and natural fibers. Natural fibers are waste materials and used in construction materials for reinforcement. Their reuse in manufacturing reinforced crude bricks is eco-friendly and improves mechanical and thermal characteristics of crude bricks. Factors such as type of fibers, percentage of fibers, length of fibers and distribution of fibers inside the bricks have significant effect on mechanical, physical and thermal properties of biobased composite materials. It can be observed by tests such as indirect tensile strength, compressive strength for mechanical characteristics, density, shrinkage, color for physical properties, thermal conductivity and resistivity for thermal properties, and inundation test for durability of crude bricks. In this study, mechanical and physical characteristics of crude bricks reinforced with palm oil fibers are investigated and effect of change in percentage and length of fibers is observed. Crude bricks of size 4*4*16 cm3 are manufactured with dredged sediments from Usumacinta River, Mexico and reinforced with palm oil fibers at laboratory scale. For this purpose, sediments and palm oil fibers characteristics were studied. Length of fibers used is 2cm and 3cm. Bricks manufacturing steps such as sediments fibers mixing, moulding, compaction and drying are elaborated. Dynamic compaction is opted for compaction of crude bricks due to energy control. Indirect tensile strength and compressive strength tests are conducted to identify the mechanical characteristics of crude bricks. Physical properties of bricks are studied through density and shrinkage. Durability of crude bricks is observed with inundation test. Thermal properties are studied with thermal conductivity and resistivity test. Distribution and orientation of fibers and fibers counting are done to observe the homogeneity of fibers inside the crude bricks. Finally, comparison between the mechanical characteristics of crude bricks manufactured with 2cm and 3cm length with control specimen was made.
Improving Performance of Thermal Modified Wood against Termites with Bicine and Tricine
Authors: Jones Dennis , Nunes Lina , Duarte Sonia
Published: January 2022

The desire to incorporate wood in modern construction has led to a considerable increase in the use of wood modification techniques, and especially thermal modification. However, thermally modified wood has poor performance against termites. The concept of using a combined chemical and thermal modification has been undertaken through the impregnation with either bicine or tricine prior to modification. This paper considers the effects of these chemicals on the activity of termites and considers their mode of action in terms of termite survival and on their effects on the symbiotic protists present within the termite gut.
Use of Hemp Fibres in 3D Printed Concrete
Authors: van Hierden Naomi Zahra , Gauvin Florent , Lucas S.S. , Salet T.A.M. , Brouwers Henricus Jozef Hubertus
Published: January 2022

The use of fibres as reinforcement of 3D printed concrete is widely known and applicable in many situations. However, most of the applied fibres are not produced from renewable resources. Natural fibres are commonly considered as an ecological alternative for these fibres. In order to contribute to improvement of the sustainability of 3D printed concrete, natural fibres such as hemp can replace these synthetic fibres. The objective of this study is therefore to study the possibilities of adding hemp fibres for 3D printing purposes. Due to the comparable properties of hemp and synthetic fibres, natural fibres tend to be suitable for printing purposes. Mixes are made at laboratory scale using batches of 1 – 3 kg. The study examines the effect of adding hemp fibres for the mechanical and fresh state properties of hemp-based concrete. Mechanical properties from bending tests and direct tensile tests show comparable properties of mortars containing hemp fibres and mortars containing synthetic fibres. The fresh state behaviour of the designed concrete mix showed promising and comparable results for a mix based on 0.5wt% of hemp fibres. One of the major issues regarding the use of natural fibres is the irregularity and high water uptake of the fibres. Due to its high hydrophilicity natural hemp fibres take up much water and can therefore degrade. For this study the effect of water uptake did not have much influence on the mixing and printing purposes. By printing a wall element on laboratory scale the use of hemp fibre-reinforced 3D concrete is validated.
Link between Acoustic and Hygrothermal Behavior of Hemp Shiv and Pith Composites
Authors: Abbas Mohamed Said , Fabbri Antonin , Ferroukhi Mohammed Yacine , Glé Philippe , Gourdon Emmanuel , McGregor Fionn
Published: January 2022

Bio-based materials are an environmentally friendly alternative to classic construction materials, yet their generally low density can lead to poor acoustic properties. The acoustic performance of hemp shiv and sunflower pith composites is therefore analyzed using Kundt’s tube. Although the loose aggregates present an exceptional sound absorbing behavior, it can be notably worsened in the presence of certain binders. The Transmission Loss is nevertheless enhanced by the binders, although it does not exceed 20 dB in most cases. For both properties, the type of binder has been found to be the most influential parameter. Through the Kundt’s tube method, it is also possible to determine the geometrical parameters of the composites’ microstructure, which have been observed to be similar for materials presenting comparable hygrothermal properties and containing the same binder. In a previous work, an experimental correlation was found between the thermal conductivity and the interparticle porosity of the aforementioned composites, which is compared to theoretical thermal conductivity models from literature without finding any apparent correspondence.
Straw Material: End-of-Life Cycle Analysis Scenario
Authors: Tornay Nathali , Floissac Luc , Garcia Coralie , Rollet Delphine , Aventin Catherine
Published: January 2022

Bio-based materials end of life is analysed from straw builders and farming practices. This paper proposes a classification of constructive straw systems according to their selective disassembly processes. According to EN 15804 standard, end-of-life (EoL) cycle analysis scenarios are used to create Environmental Product Declarations (EPD). These data will be used: - for architectural projects conception in respect to“RE2020” new French regulation. - as an awareness-raising approach for the long term design of constructive systems.
Compatibility of Plants with a Mineral Binder
Authors: Marceau Sandrine , Lacour Lucie , Diafi Dinarzed , Farcas Fabienne
Published: January 2022

Hemp concretes are the most widely used biobased concretes in France. However, their growth is still limited by the lack of knowledge and high variability of the performances of biobased concretes, especially for their mechanical properties. These results are related to interactions between the mineral binder and plant compounds that modify the hydration of the cement. In this work, the interactions between cement and eight types of hemp shiv, and a flax shiv are studied by isothermal calorimetry. The setting delays observed in the presence of plants are interpreted by analyzing the molecules extracted from these plants in water. A link can be observed between the setting delay and the coloration of the extract solutions or their concentration in reducing sugars and in polyphenols. These results constitute a basis in the objective to define an indicator enabling to predict the compatibility between plants and mineral binders.
COVID-19 Lockdown Home Gardening in the Western Province of Sri Lanka
Authors: Perera T. G. U. P. , Wickramaarachchi N. C. , Karunarathne H. M. L. P. , Munasinghe Lasika Madhawa , Rupasinghe Kasuni
Published: January 2022

Sampling a set of households from three districts of the Western Province, this paper explored the landscape of lockdown home gardening which took place during the first wave of the COVID-19 pandemic in Sri Lanka. A structured questionnaire published online enabled collecting 939 household responses. A descriptive analysis performed using the IBM SPSS package highlights that the lockdown conditions have intensified the level of home gardening of the participants. The study validates the findings from recent studies that home gardening has no dividing line when it comes to the socio-economic character of households. Primary benefit of home gardening is of households’ being in seek of good and healthy consumption, vegetables and fruits have been the most preferred crop types to grow. Application of organic fertiliser have been preferred by the majority of the households. This study supports the notion that urban land scarcity is not a limiting factor for home gardening. The paper suggests that this home gardening trend reignited during the Covid-19 lockdown needs to be supported by three means: promoting healthy lifestyles, connecting government officials with local home gardeners and local plans being supportive and appreciative of home gardening.
The Impact of Community Conflict on Tourists’ Behaviour in Sri Lanka: A Case of Madunagala Hot Spring Area
Authors: Bogahawatta Chandima
Published: January 2022

Tourism that is engaged with local communities offers a multitude of opportunities and economic benefits to the community. When the local communities do not get sufficient economic benefits from tourism, their competitive reactions to earn more economic benefits create conflicts. A conflict occurs when the goal of an individual or a group is interrupted by another group. The dissatisfactions of tourists can affect tourism-related conflicts of a particular destination. This paper is based on a qualitative study done at Madunagala Hot Spring to identify the background of community conflicts due to tourism and how they influence tourists' behaviours. The local community which was investigated during the study includes vendors at Madunagala Hot Springs. Due to the lack of economic benefits, competition occurs between permeant shop vendors and temporary shop vendors when dealing with tourists. The study is based on the objectives to identify how negative impacts of conflicts on tourists' behaviours can be reduced through the findings of the study. Primary data was gathered by a three day field observation at the site, and personal interviews with vendors and domestic tourists were done under the unstructured interviewing technique. The content analysing method was adapted for data analysis. Tourist behaviours vary due to vendors' conflicts that create disasatisfaction among tourists. Conflicts can be reduced by introducing new selling techniques such as product diversification, and vendors should be aware of tourism. Attitudes of tourists also should be improved to create a conflict-free environment at the site.
Tumor-Induced Osteomalacia
Authors: Dharmalingam Mala , Kumbar Lohit
Published: January 2022

Tumor-induced osteomalacia (TIO), is a rare paraneoplastic syndrome resulting in bone pain, muscle weakness, and recurrent fractures. Hypophosphatemia, hyperphosphaturia, low 1, 25 dihydroxyVitamin D, and normal serum calcium are noted. It is mostly caused by fibroblast growth factor 23 (FGF23) secreting tumors. Apart from testing for FGF23, additional imaging modalities are required to identify the causative lesion. Prompt remission follows successful lesion excision. This case report highlights the importance of FGF 23 in the diagnosis of TIO.