The energy and environmental transition in the building sector requires the development and use of low-impact materials. Despite the growing interest in bio-based and earth-based building materials, ...their widespread adoption is still limited due to a lack of hindsight, as their study is relatively recent. This study aims to contribute to the development of these materials by providing an extensive overview of key contributors (authors, countries, journals) in these fields. Then, the keywords of the corresponding publications were analyzed to reveal the main topics covered to date. First, a broad scale is presented, followed by a focus on sub-categories, specifically raw materials for bio-based building materials and implementation techniques for earth-based ones. Finally, a comparative analysis, with the themes covered by composite construction materials as a whole, completes the study. Using statistical analysis coupled with bibliometric network visualization software, this study provides clear, quantifiable, and objective insights into current trends. Furthermore, it facilitates the identification of new, promising research perspectives and highlights the importance of interdisciplinary collaboration. Physics, modeling, durability and microstructure studies emerge as relevant levers for advancing the future development of these eco-friendly building materials.
Radon gas is known to exhale from the ground and can enter and accumulate inside buildings. Many countries set radon limit concentrations and propose mitigation techniques applied in the outdoors to ...prevent radon from entering buildings. However, radon can also exhale from building materials, e.g. cement, bricks, marble or tiles, contributing high concentrations indoors. Space ventilation is the most used technique to reduce the indoor radon concentration to safe limits, but sometimes, it is not enough. In these cases, it is necessary to apply alternative techniques. This work exposes a prevention technique to reduce radon concentration in indoor spaces that come from building materials or from the subsoil diffusing through basement walls, based on the use of wallpapers. The use of wallpapers is a common decorative technique in homes and buildings, which is compatible with interior finishes and is simple to apply, easily accessible, commercially available and inexpensive. Different commercial wallpapers were selected with a cellulosic and polymeric base and vinylic, cellulosic, latex or non-woven coating material. Configurations of single and double layers of wallpaper and a triple configuration by adding an intermediate layer of aluminium film have been tested. Tests to determine the reduction of radon concentration were performed, and diffusion coefficient and diffusion length were calculated following an adaptation of ISO/TS 11665–13 standard. Radon reduction of 90%, low-medium radon resistance and a diffusion coefficient around 10−11 m2/s were reached for single-layer configuration, and up to 98% of radon reduction, medium radon resistance and diffusion coefficient of 10−12 m2/s with double-layer configuration for dense non-porous base wallpapers with vinylic and non-woven coatings. Adding an aluminium foil intermediate in the double configuration improves the results of all wallpapers tested regarding radon reduction concentration, radon resistance, diffusion length and diffusion coefficient. Moreover, for the dense non-porous base made of non-woven fabric with a vinyl coating layer wallpaper, the diffusion length is shorter than the thickness of the sample in this configuration so the amount of penetrating radon will be reduced by the decay of radon in the wallpaper. Therefore, most radon would disintegrate along the sample and the concentration in the interior space would be lower. These results open a new alternative to protect indoor spaces from radon that access through walls or building materials based on a simple, easy and low-cost technique.
•Radon indoors comes mainly from the soil through the basement and from building materials exhalation.•When ventilation is not enough to reduce it, alternative techniques should be applied.•Wallpaper is a common decorative technique that can be used as indoor radon barriers on walls.•Wallpaper of non-woven base with vinyl coating is the best material tested.•Double-layer configuration wallpaper barrier has a radon resistance of 162 Ms/m.
•About 88% of the MI in Finnish wooden houses comes from concrete.•Construction method, GFA and footprint shape significantly affect MI.•The number of storeys in 1–1.5 storeys buildings does not ...significantly impact MI.•The variability in MI within each building typology should be accounted for.•Comparing of MI faces challenges due to a lack of harmonized data and methods.
Improving resource efficiency in the building sector is a significant challenge, largely due to a lack of knowledge about material usage in buildings. Material intensity (MI) quantifies materials used in buildings, normalized by floor area or volume. MIs serve as indices for material stock and flow models and as an inventory approach for assessing the environmental impact of the built environment. Therefore, this study aimed to determine MIs of Finnish wooden residential houses built between 1940 and 2010 due to the dominance of them in residential building stock and their demolition rates. Factors influencing MI and cross-country comparisons were also explored because they had not been explored enough in the literature. Results showed construction method, time cohort, floor area, design choices and footprint shape impacted MI. Accounting for variability of MI was recommended, particularly when using it for material stock and flow analysis. Data and method disparities restrict cross-country comparison of MI.
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In recent years, wood has received increased interest in Europe as a multi-storey building material. The trend is driven by the recognition that wood, as an environment friendly material, can ...contribute bioeconomy development and the achievement of sustainable development goals. In Lithuania, multi-storey wood-based building is still at the level of policy and political discussions. Therefore, the presented research focuses on quantification and comparison of the sustainability impacts of both wood- and concrete-based building materials value chains and provides applied scientific knowledge relevant to decision makers and in this way contributes to mitigation of the climate change.
In detail, study covers the production value chain – from raw material extraction to manufacturing using the same method, while documenting and assessing the material sourcing stages transparently and consistently. In our study glue laminated timber and sawn timber building materials represented renewable material value chains, while site-cast concrete and precast reinforced concrete building materials represented non-renewable materials value chains. In discussion with study partners in the BenchValue project and during a project stakeholder workshop, twelve environmental, social and economic indicators were selected to perform the sustainability impact assessment of selected building materials. Building materials were compared by using a decision support tool ToSIA. The relevant data was gathered from local, well-known companies in the national and international arena.
Our results revealed that glue laminated timber and sawn timber value chains compared to site-cast concrete and precast reinforced concrete value chains have more positive sustainability impacts. This is especially true when analysing environmental indicators: GHG emissions, Energy use, Generation of wastes and Water use. Analyses also revealed more positive socio-economic impacts of wood-based building materials. The socio-economic advantage of wood could increase competitiveness of the regions and contributes to their sustainable development.
Our paper is in line with the applied research. Since it is a case study, the presented results are country specific, because the estimation of indicators was done by applying local data. The presented research is relevant to policy experts and decision makers in the context of the reduction of CO2 emissions. Also, this paper is relevant to the companies and architects who want to build and compare various building materials. Partially, results of this paper could be applied in other countries with comparable to Lithuania economic development level, having in mind the possible shortcomings already highlighted.
•Sustainability impact assessment of building materials are critical for decision makers and influence the choice of materials.•SIA of wood- and concrete-based building materials production value chains (A1-A3) were compared.•A decision support tool ToSIA was applied.•Wood-based value chains showed more positive sustainability impacts compared to concrete-based value chains.•Wood could be the key component in increasing the sustainability of the national construction sector.
Air movement dries surfaces by increasing evaporation and convection, which may prevent mould growth. Cladosporium sp. is used as the test organism (dominant fungi in the envelope of rural houses in ...hot summer and warm winter areas), and the effect of fans on inhibiting mould growth on building materials is investigated. Surface mould growth on materials was simulated and compared after rain leakage and surface condensation, and spore germination was studied in high humidity, with or without airflow. The results are as follows: (1) Airflow has an evident inhibitory effect on mould growth on wet building materials. This observation was linked to the availability of moisture content in the building materials. (2) Airflow can slow the appearance of visual mould on the material surface. Mould did not appear on the gypsum surface due to the airflow, and mould growth on a wood surface was delayed for about two days. (3) Periodically, spore eluates were examined by electron microscopy to determine the stage of spore germination, and it was found that airflow delayed mould spore germination for about 2–3 days.
One of the main phases formed at the beginning of the carbonation reaction of cementitious building materials is the calcium hemicarboaluminate (abbreviated as Hc). This AFm (shorthand for hydrated ...calcium aluminate phases structurally related to hydrocalumite) phase was synthesized, crystallized and then studied by synchrotron X‐ray powder diffraction and micro‐Raman spectroscopy. At room temperature and standard experimental conditions two major cementitious phases were detected, the Hc phase (as a major phase) and carbonated calcium hemicarboaluminate (abbreviated as cHc). By increasing the temperature the Hc form transforms into cHc. The crystal structures of these important AFm phases were successfully solved and refined in the space group of the trigonal crystal system. Hc has the unit‐cell parameters a = 5.7757 (1) and c = 48.812 (2) Å, and cHc the unit‐cell parameters a = 5.7534 (1) and c = 46.389 (1) Å. The two crystal structures are composed of positively charged main layers, Ca4Al2(OH)122+, and negatively charged interlayers, OH2n(CO3)1 −n·4H2O2−. The structure of the main layers is typical of the AFm family. Conversely, the interlayer region has a characteristic structure built up from water molecules and statistically distributed anions. In the interlayer, the Hc carbonate and hydroxyl anions are distributed in a 0.25:0.5 ratio, whereas the ratio of the anions in the cHc interlayers is 0.4:0.2.
The transformation from the building material industry (BMI) to green BMI (GBMI) is not only of great significance to the upgrading of traditional BMI, but also has a pivotal role in promoting the ...sustainable development of cities. This paper studies the governance mechanism of the BMI in transformation to GBMI from the perspective of supply-side and demand-side of green building. First, evolutionary game theory is used to develop two three-party dynamic game models including building materials enterprises (BME), government, building developers (BD) and building consumers (BC). Second, numerical simulation experiment method is used to study the multi-stage governance mechanism based on the model deduction and the theoretical analysis of green transformation. The numerical simulation results show that the infrastructure construction projects on green building is an important governance mechanism for the rapid development of the GBMI, and the green innovation subsidy is a core governance mechanism for the high-quality development. The punishment of pollution and fraud compensation punishment and green innovation subsidy to green BME, tax incentives to green BD and purchase subsidy to green BC are conducive to promoting the change of the concept of green production and consumption. The aforementioned mechanisms and infrastructure construction contribute to promoting the production of green building materials in BME through developing and purchasing green buildings. The infrastructure construction and green innovation subsidy play a pivotal role in the high-quality development of the GBMI. This study not only reveals the theoretical mechanism of the BMI in transformation to GBMI under government-driven, but also provides a practical guidance for formulating high-quality development policies for GBMI. In addition, questionnaire method can be used to effectively solve the problem of bringing the four parties into a unified framework for future research.
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•The perspective of supply-side and demand-side of green building.•Two three-party game models including BME, government, BD and BC are proposed.•Governance mechanism is put forward based on target efficiency at different stages.•Construction of infrastructure projects on green building is an important measure.•Technology innovation is a core mechanism for the rapid development of the GBMI.
The accelerated weathering of limestone (AWL) process is an inexpensive and eco-friendly carbon dioxide (CO2) capture process with comparable performance to amine-based systems. However, the ...generated calcium bicarbonate (Ca(HCO3)2) solution lacks an effective utilization alternative. Aside from that, the current solid waste utilization alternatives (i.e., carbon mineralization and partial replacement of conventional binders) lack the capability to effectively curb the tremendous production rate of solid waste (i.e., cement kiln dust (CKD)). To address both gaps, this study developed a novel Ca(HCO3)2 solution utilization alternative with CKD as the sole binder to produce a building material termed CKD-bicarbonate lime mortar (BLM). This work aims to identify the optimal mix ratio for CKD-BLM to achieve maximum compressive strength via a series of studies; (i) liquid medium, (ii) Ca(HCO3)2 solution volume, and (iii) sand:CKD mix ratio. From the findings, it was found that CKD-BLM at the optimal CKD:sand:Ca(HCO3)2 mix ratio of 1:0.45:0.29 exhibits the highest compressive strength of 2.09 MPa, surpassing the compressive strength standard of 1.70 MPa set by the ASTM C141 while having acceptable workability of 118 % which is within the standard workability range of 105–155 % set by ASTM C270. However, the CKD-BLM sample exhibits high leaching of Ca, Si, Na and Cl which does not meet the environmental regulation. This was resolved by applying a waterproof coating that effectively curbed the leaching by 28.84–99 %. Overall, this study successfully developed a building material with industrial wastes (i.e., Ca(HCO3)2 solution and CKD) that surpasses the performance of conventional lime mortar while utilizing up to 0.22 kg CO2.kg CKD-BLM_1:0.45:0.29−1.
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•Cement kiln dust is used as feedstock for bicarbonate mortar production.•CKD-BLM_1:0.45:0.29 was able to achieve a strength of 2.09 MPa.•Generated CKD-BLM are able to meet ASTM standard requirements.•Able to achieve a CO2 storage capacity of 0.22 kg CO2.kg CKD-BLM.•Encapsulation with waterproof coating can curb heavy metals leaching up to 99.17 %.
One novel lightweight building material was successfully manufactured using magnesium oxysulfate (MOS) cement as binder and foam and/or rice husk as inert fillers in this paper. It behaves much ...higher specific strength and lower environmental load than normal concretes prepared by Portland cement, natural sand and aggregates. To improve the mechanical strength and water resistance of MOS matrix, three kinds of weak acids were incorporated at low levels. On the basis of the modified MOS matrix, foam, rice husk, and the mixture of foam and rice husk were added at variable dosages as fillers to prepare MOS cement based lightweight materials. Mechanical strength, bulk density and compressive strength/volume deformation of these materials were evaluated after variable wetting-drying cycles. At the same time, phase composition and microstructure of typical samples were studied using X-Ray Diffraction (XRD), Fourier Transform Infrared Spectrometer (FTIR), Opto-digital Microscope (OM) and Scanning Electron Microscope (SEM) tests. Experimental results indicated that the addition of 0.5% citric acid by MgO weight can greatly enhance compressive strength and water resistance due to the formation of finer needle-like crystals of 5 × 1 × 7 phase instead of 3 × 1 × 8 phase. The higher incorporation of foam and rice husk decreases bulk density and mechanical properties of MOS cement pastes. With a density of as low as 1000 kg/m3, the compressive strength of MOS cement based lightweight materials can reach higher than 12 MPa. The wetting-drying treatment leads to a negative effect on both compressive strength and volume stability of these materials, due to the transformation of unreacted MgO into Mg(OH)2 crystals upon water immersion. On the other hand, the coupling effect of water-swelling and drying-shrinkage induces the formation of micro cracks in specimens. A proper addition of foam bubbles and rice husk presents the better resistance to wetting-drying cycles. Therefore, the MOS cement based lightweight material could be widely applied to inner partition walls and structural component, and its long-term service behavior should be further assessed.
•Gypsum boards added with porous materials and phase change materials were prepared.•Hygrothermal performance of specimens was analyzed based on ISO 12,571 and 12,572.•Thermal conductivity of ...specimens was lower than conventional gypsum board.•Water vapor resistance factor was higher than gypsum board after impregnation of PCM.•There were no moisture problems of gypsum boards with porous materials and PCM.
Gypsum board is widely used as a finishing material, and it is mixed with functional materials to improve the comfort level of indoor air, provide thermal insulation, and satisfy moisture properties. In addition, Phase change material (PCM) is also used as a functional material to reduce energy consumption. Recently, there have been many studies on improving moisture problems, such as condensation and mold growth. Therefore, the hygrothermal behavior of building materials must be carefully considered to reduce the risk of moisture problems. The objective of this study was to improve the thermal and moisture performance of gypsum board, and achieve energy savings by adding porous material and PCM. The characteristics of functional gypsum board (FGB) with expanded vermiculite (EV), expanded perlite (EP), nano carbon material (C300), and n-octadecane (PCM) were analyzed by fourier transform infrared (FTIR) spectroscopy for structural stability. The thermal conductivities of the various FGBs were analyzed by TCi thermal conductivity analyzer, and their hygroscopic properties were analyzed based on ISO 12,571 and 12,572. In addition, the hygrothermal performance of walls applied with FGB was evaluated using Wäme und Feuchte instationär (WUFI) simulation; the wall composition was concrete wall. As a result, the thermal conductivities of FGB were decreased by 15%, compared with the conventional gypsum board. In the case of moisture properties, the water vapor resistance and water content of FGB were increased, compared with the conventional gypsum board (SR). However, the simulation results showed that there were no moisture problems, such as condensation, mold growth, or structural damage.
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