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Advances in thermal energy storage techniques/methods, using Phase Change Material (PCM), have gained much hype among researchers in the last decade. Thermal energy storage systems can significantly reduce energy consumption and promotes the use of renewable sources of energy. In recent decades, the building sector has evolved as one of the major consumer of energy resulting in high levels of carbon emissions. Thermal energy storage combined with PCM is an effective method for improving the energy efficiency of the buildings. PCM can be incorporated in the building envelope in many ways. One of the simplest and effective method of integrating PCM directly in building material is macroencapsulation. This method not only improves the indoor thermal behavior of the buildings, but also reduces the cooling load without or little compromising with the mechanical strength of the building structure. In this article, a critical review of the application of macroencapsulated PCM in buildings for energy savings has been carried out. A detailed review of various approaches to integrate the macroencapsulated PCM in the building envelope has been shown. Effect on indoor thermal behavior and reduction in cooling load was analyzed for different approaches. Additionally, the compatibility of various materials used for making containers for encapsulation was also investigated. A detailed description of macroencapsulation technique, types of thermal energy storage methods used in buildings, suitable PCM available for encapsulation has also been shown in the article.

Beijing marble has been used as a construction material for cultural heritage sites in Beijing area, China. The Forbidden City, the Temple of Heaven, the Summer Palace, and the Thirteen Ming Tombs are classified as UNESCO World Heritage sites. In this paper, detailed experimental and analytical investigations of two representative sub-types of Beijing marble are presented. Marble samples were collected from a historical quarry in Dashiwo County of Beijing’s Fangshan District. Mineral and chemical constituents were investigated through petrographical observations, X-Ray Diffraction (XRD) analysis and X-Ray Fluorescence (XRF) analysis. Physical parameters (e.g., density, porosity, water absorption, pore size distribution, P-wave velocity (VP), seismic anisotropy (AVP), hardness, etc.) and mechanical parameters (i.e., uniaxial compressive strength (UCS) and Young’s modulus (E)) were tested in accordance with British and Chinese standards. Correlations among tested parameters were also analyzed to better understand the internal relations among different properties and to aid in evaluating unattainable parameters during in-site heritage site assessments. To get a more comprehensive understanding of the marble’s characteristics, we collected and analyzed those physico-mechanical data reported by previous researchers. Additionally, the weathering mechanisms and resistance of the marbles were discussed from different perspectives. The results of this study provide scientific data on the properties of Beijing dolomitic marble, which have practical use for weathering assessments and reconstruction of cultural heritage sites. Additionally, the results of this study provide a reliable reference for studying worldwide marbles with different geological origins.

This paper discusses on the efficiency of partial replacements of fine aggregate (sand) by waste crumb rubber for improving the deformability and structural ductility of the reinforced concrete (RC) frame and thus resisting progressive collapse. This research experimentally tested the behaviour of four RC frames at one-third-scale under the middle column removal scenario. For comparison, two frames were prepared for 0% crumb rubber as the controlled specimens. The remaining frames were prepared for 20% crumb rubber replacements by volume for sand. The mechanical properties, failure mode, the crack pattern, the load-displacement behaviour, and structural ductility are analysing herein for normal and RuC frames. Results indicated that there was enhanced in structural ductility induced by the addition of crumb rubber in conventional concrete. Meanwhile, the RuC frames showed more deflection than the NC frames. Therefore, RuC is an eco-friendly building material that can be used for enhancing the ductility of RC elements as a new design strategy for preventing progressive collapse.

The present study was undertaken to evaluate the potential of dimensional limestone waste (DLW), generated during cutting and polishing activity, as fine aggregate in mortar mixes. For this, the generated waste was used in two forms, first as slurry and second as manufactured sand. A total of fourteen mortar mixes (volumetric ratio 1:3 and 1:6) were prepared by replacing conventional fine aggregates (river sand) between 0 and 60% with dimensional limestone slurry (DLSS) and manufactured dimensional limestone crushed sand (DLCS). These mortar mixes were evaluated on the basis of workability, compressive, flexural, adhesive and tensile bond strengths, drying shrinkage, water absorption, porosity, density, ultrasonic pulse velocity, and dynamic modulus of elasticity. A positive impact of DLW on strength properties of mortar mixes was observed between 20 and 60% replacement of conventional river sand. Use of DLW resulted in a much denser and homogeneous mixture, reducing water-cement ratio, and improving the workability of mortar. Using DLW as partial replacement of fine aggregate resulted into improved strength properties of mortar. However, above 20% replacement, the drying shrinkage of all mortar mixes increased continuously. Structural matrix of mortar mixes, analyzed by scanning electron microscopy (SEM) images, Fourier-transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) substantiate the above results. Use of DLW as partial substitution of conventional river sand may help to conserve the non-renewable natural resources with alternative building material.

There is a rapid development of earth construction the last few decades followed by an increased interest in scientific research in this field. One of the issues that have arisen is which soils are suitable for construction and can be designated as construction soils and which are not. Thus, the main objective of this paper is to investigate the relation between physical soil properties and mechanical properties of the dried building material. In this context, the Cation Exchange Capacity (CEC) of the soil is investigated in this research as an innovative tool in soil assessment for earth building. The distinct advantage of CEC is its dependence on clay type and organic matter apart from clay content, which is the soil property most frequently used in soil assessment for building purposes. This study focuses on earth mortars, on which little experimental research has been carried out despite their widespread use. In order to overcome the issues often mentioned in literature of using a certain soil and then generalizing the results, it was decided to use a wide range of soils with different textures from various regions of Greece. So, 26 soils were collected and a total of 49 earth mortar mixes were fabricated in two phases. The soil properties assessed were texture, Atterberg limits, CEC, mineralogy and organic matter content, while the hardened mortar properties assessed were compressive strength, flexural strength, dry density and linear shrinkage. It was found that CEC provides stronger correlation with compressive strength and linear shrinkage than clay content and Plasticity Index. A linear correlation between linear shrinkage and compressive strength was also established. Finally, it is shown that the soils with high organic matter content used in this research, are unsuitable for earth building despite having sufficient compressive strength.

In the context of sustainable development, the use of eco-friendly building materials has been considered as a solution to environmental pollution problems caused by fossil fuels. In this study, novel bio-composite were prepared using biochar and natural inorganic clay (NIC) to evaluate the applicability of biochar to buildings. After preparing the rice husk, coconut shell, and bamboo biochar, these were mixed into NIC at four ratios to form a board, and their morphological, thermal, and moisture performance were analyzed. Through morphological analysis using field-emission scanning electron microscopy, the microstructure of each biochar was confirmed, and the shape of each biochar was confirmed in the bio-composite mixed with biochar. As a result of TCi analysis, it showed that the maximum rate of decrease of thermal conductivity was 67.21% by biochar. As a result of dynamic heat transfer analysis, it was confirmed that it is less sensitive to thermal change due to low thermal conductivity of biochar. Also, the CUP test showed that the water vapor resistance factor increased up to 22.58% when mixed with biochar, which means that the biochar can reduce water vapor permeability. In conclusion, biochar can be used to make environmentally friendly and energy efficient building materials.

The present review manuscript examines the most essential phases in the developments of the inorganic class of environmentally benevolent Geopolymer concrete focusing on the valorisation of Waste of Glasses in context of incorporation in the manufacturing of Geopolymer concrete, especially concerning to its properties and applications. Their long-standing applications as structural materials developed through activation of alkali, i.e., Geopolymerization, in the field of sustainable constructions and infrastructures industries, diverse GPC are on the map. Even though, more advanced studies in the context of the said concept will be proved valuable to concerned industries people and of course, to the researchers themselves. Although the available literature in this innovation zone is few and far between, it breaks the surface, for the most of the centre of attention on its, incorporation with other waste materials pointing a finger to its approach to embrace “waste for the best” strategy. Previously, their character is neither well-figured out nor aptly welcomed as in the ordinary Portland Cement based edifice materials enjoying. That is the core reason and objective of this article that review of its handy restricted literature to throw lights on the valorisation of blending of Waste of Glasses for the manufacturing of Geopolymer concrete centring its attributes and uses establishing it as a soon-to-be useful lucrative and sustainable global building material. The suggestions pointed out here in this manuscript will confidently be accommodating for potential research works on the topic. However, a modest challenge viz., curing complications, sometimes practical confronts of application, constrained supply chain, and a prerequisite for an observant directive of mix design for its fabricating, are standing up in its tracks to substitute Ordinary Portland Cement counterparts. Even so, when produced by utilizing vast and within reach precursors, activators and waste glass materials under up to the standard quality control of diverse characteristics, predominantly strength and green footprints of alkali activators, valorisation of Geopolymer concrete incorporated with waste glasses are momentous forthcoming part of the prospect toolbox of sustainable and economically reasonable construction materials. Eventually, the paper categorizes promotion of applications and most importantly the properties aspect for this promising novel type of building material.

Soil, as an important building material, has been widely used for a long time. Earthen sites are representative ancient buildings made of rammed soil. As significant archives of human history, culture, and architecture, earthen sites are seriously deteriorated by age, poor conservation, and exposure to the environment. Therefore, the restoration and protection of earthen sites are necessary and urgent. Northwest China has a long history and the earthen sites in this area are widely distributed, numerous and highly valuable. In order to understand the characteristics of the earthen site, a typical site in this area is taken as a case to test the physical, mechanical, and environmental durability of the site soil. The site soil is silt; it is low in the liquid limit and plastic limit, the particle size distribution is good, the material is uniform and compact, the density and strength are extremely high, and the environmental durability is excellent. In view of the problems existing in the earthen site restoration, such as over-reliance on chemical methods, risk of causing new damage and poor similarity after restoration, this paper proposes that the earthen sites should be restored with the material and technology which are similar to the original site. In order to make the restoration material as close to the original site as possible, the soil near the site is selected and particle size distribution is optimized. By changing the variable factors in compaction test, namely hammer weight, hammer blow number, and the drop distance, the compaction mechanism of the site soil is tested; the influence of different compaction factors on maximum dry density is revealed; and a compaction influence parameter λ is introduced to evaluate the influence of compaction factors on the maximum dry density. Contrast test shows that by selecting similar materials and techniques, the maximum dry density and other engineering properties obtained from the compaction test are close to the original site soil. The comprehensive performance of the compacted sample is much better than lime soil which is usually used to restore earthen sites. This result shows that it is feasible to select nearby materials and original techniques so as to make restoration site more similar to original site. The findings in this paper can provide reference for better restoration of earthen sites.

Municipal solid waste incinerator (MSWI) bottom ash (constituting approximately 80–90%) and fly ash are by-products of the incineration of solid waste. In general, MSWI residues are primarily discarded into landfills. To address the continuous growth of landfills and to implement zero waste and circular economy policies, researchers are focusing on more efficient ways of using MSWI bottom ash. To that end, the best practices show that MSWI bottom ash is suitable for civil engineering applications, especially roads. Therefore, the subject of this research was the performance of subgrade and different unbound and bound pavement structural layers containing bottom ash. An algorithm was also introduced to facilitate the use of MSWI bottom ash as a building material. Soil and mineral aggregate mixtures with different percentages (0–100%) of bottom ash were designed and analysed, and more than 10 testing subjects containing a high amount of MSWI bottom ash were tested in the laboratory. The research revealed the suitability of the 0/2 fraction of bottom ash to improve soil and to enhance the performance of asphalt concrete mixture AC 16 PD in which the 0/4 fraction of sand is replaced with the 0/2 fraction of bottom ash. Furthermore, the suitability of mixtures composed of mineral aggregates and MSWI bottom ash or only of MSWI bottom ash (100%) to construct sub-base and base courses was confirmed.

Plantation softwood is the future timber material resource for building and construction. However, significant volumes of sawn softwood are considered out-of-grade and sold at a loss. New approaches and methods need to be implemented to value-add out-of-grade timber and increase structural yield from existing plantations. This paper provides a critical review of out-of-grade characteristics of pine timber to gain an understanding of the strengths and weaknesses of this resource as a structural building material. Methods to incorporate out-of-grade timber into current building systems are presented and building technologies that can facilitate this use are identified. Finally, it discusses developments and important considerations for design of cross laminated timber (CLT) as a prime example of a building system with good capacity to incorporate high volumes of out-of-grade timber. This provides critical information for the maximum utilisation of sawn out-of-grade pine and is anticipated to create new opportunities that can effectively incorporate this renewable and sustainable material resource into innovative building systems and technologies.

Water hyacinth (WH) is an invasive aquatic with an extensive, rapid growth. Nowadays, the considerable amount of WH biomass generated is a waste management challenge for those areas where WH is present. In this paper, a new insulation building material based on WH’s petioles (WHP) and mixed with cement was analysed. Different WHPs particle sizes were processes (pulp WHPs and staple WHPs). As a consequence, two type of panel were studied. Both panels used different WHP content ranging from 40:60 (WHP:cement) to 100:0. According to the results, self-supporting WHP-cement board could be used as an alternative insulation material. The optimum percentage (WHP:cement) was 80:20 for panels made with pulp WHP and 75:35 for panels made with staple WHPs. Their thermal conductivity values were 0.63–0.45 W/mK respectively.

Currently, wood is attracting attention as an eco-friendly building material that has advantages such as high insulation performance and low CO2 emission. However, it is vulnerable to moisture. Therefore, the objective of this study was to develop wood-lime boards using lime as resins that is known to be excellent in moisture control. Hygrothermal behaviors of such wood-lime boards were then analyzed to confirm their applicability as building materials. Results of hygrothermal behavior analysis revealed that they had higher insulation performance and higher water vapor resistance factor. Simulation analysis results also indicated that both total water content and mold growth risk were reduced when wood-lime boards were used in comparison with existing layers. Therefore, wood-lime boards were applicable as building materials.

In this work four incineration bottom ashes (IBA) and coal fly ash (CFA) were directly treated in hydrothermal conditions in autoclave. However, not each ash solidified into a solid product. Therefore, it was checked whether the modification of calcium oxide/silica (C/S) molar ratio of the initial mixtures to the value of 0.83 would enhance the properties of such products. The modification improved the compressive strength of the autoclaved ashes as compared to samples with unchanged C/S ratio in the case of each investigated ash (e.g. from 23.5 to 74.9 MPa). The ashes and products were characterized in detail (XRF, XRD, FTIR, Raman). The heavy metals leaching was conducted to assess the toxicity risk. The regulatory limits for the safe application were not exceeded. Heavy metals were almost totally immobilized in the obtained matrices (over 99%). Therefore, presented procedure can be simply applied for the conversion of hazardous incineration bottom ash into non-toxic material, which can be applied as building material.

This study evaluates the thermal properties of cement mortar using by-product ferronickel slag (FNS) fine aggregate and its residual strength after high temperature exposure. Compressive strength of mortar increased when FNS was used up to 50% replacement of sand and then reduced with further increase of FNS. Volume of permeable voids (VPV) increased by 4% and 7% respectively for using 50% and 100% FNS fine aggregate. Thermal conductivity of mortar decreased from 2.34 W/m.K for using 100% sand to 1.65 W/m.K and 1.16 W/m.K for 50% and 100% FNS, respectively. Similarly, specific heat increased from 2.18 MJ/m3.K to 2.43 MJ/m3.K for 100% replacement of sand by FNS. These changes of VPV and thermal properties are attributed to the cavity of FNS particles, and their larger size and angular shape. Residual strengths of mortar after exposure to 800 °C were found marginally less for using FNS aggregate. This is attributed to the decrease of thermal conductivity of mortar by FNS. Overall, FNS aggregate showed improved thermal insulating properties and thermal mass of mortar without compromising compressive strength. Therefore, FNS can be considered for use as an energy efficient sustainable building material.

The use and development of earth as a building material is notably constrained by its specific thermal and mechanical behaviours in relation to water, currently not considered in construction norms and technical guides. As the compressive strength decreases with the presence of water in pores, a good prediction of water content evolution within earthen walls is critical to ensure safety. The key parameter driving the flow of liquid water through the material is the intrinsic permeability. In this paper, a novel analysis of the water absorption test is developed, enabling thereby the identification of the intrinsic permeability. Through the comparison with permeability measurements made with an oedometer at a variable hydraulic load for samples with different dry densities, this new method could be validated. This work gives therefore the opportunity to use simple standard absorption tests to assess the intrinsic permeability of earthen materials.

The physico-chemical analysis of bark-free oil palm trunk (OPT) in comparison with rice husk (RH) was evaluated for their suitability in building construction. The results showed insignificant differences in both chemical and proximate analysis of the two fillers. The optimum value for flexural and nail-pull hardness test was at 20% OPT loading. The OPT mixed gypsum composite shows good thermal stability suitable to be used as a new type of filler for the reinforcement of gypsum composite. The limitation however is its hygroscopic properties that might affects the dimensional stability of gypsum composite when contact with water.

International audience; Hygrothermal behavior of a new building material, composed of cement, sand and date palm fibers was investigated in the present work. In a first part, the sorption-desorption isotherms and the hysteresis effect were characterized under static conditions, and collected results revealed a high hydric capacity of this Date Palm Cement (DPC) mortar. In addition, the GAB model (Guggenheim-Anderson-de Boer) was successfully applied to describe the experimental sorption isotherm curve. In a second step, the moisture buffer value and the effect of temperature on successive adsorption/desorption cycles were assessed under dynamical conditions. It was found that the sorption process is highly affected by temperature. Finally, this bio-based mortar was classified as hygroscopic and breathable material with excellent moisture buffering capacity.

It is commonly known that materials behave differently under static and dynamic loadings. Clay brick is a vastly used building material. Systematic studies on the dynamic material behaviours of clay bricks are still very limited in the open literature, and the dynamic effect on clay brick material properties is not well investigated. This study carried out both low-speed and high-speed compressive tests on three types of clay bricks, i.e. high-strength, mid-strength and low-strength, made with Western Australia clays. The compressive strengths, ultimate strains and Young’s modulus of the three different types of bricks at different strain rates (from 1.67 × 10−6/s to 0.08/s and 190/s to 337/s) were quantified. The test results showed the compressive strength was very sensitive to strain rate effect, while the ultimate strain and Young’s modulus also exhibited strong strain rate dependency in high strain rate range but appears to be less sensitive to strain rate in the low strain rate regime. Based on the test results, empirical relations of dynamic increase factor (DIFs) for compressive strength, ultimate strain and Young’s modulus with respect to strain rate were derived for each type of brick. Discussions and comparisons were made on the dynamic fracture processes and specimen fragments to explain the dynamic enhancement in brick mechanical properties.

Red mud is a NORM residue of aluminum industry, and its large storage endangers environmental safety. In this study, red mud was used to prepare geopolymers to dilute its radioactivity. The activity concentrations of 226Ra, 232Th and 40K of geopolymers with different contents of red mud (0, 30, 50, 70 wt%) were investigated, and the activity concentration index, annual effective dose and shielding rate were calculated to evaluate the radiological safety and solidification effect of geopolymers. The solidification/stabilization mechanism of geopolymers was discussed by using X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). The results showed that the hydration process of geopolymers had a solidification effect on the radionuclides contained in red mud. When the red mud content was 30 wt%, the radioactivity was within the safety threshold as a building material, and the compressive strength of the geopolymers reached 72.19 MPa. The maximum red mud content in geopolymers was 40.81 wt% by fitting. The adsorption effect and the encapsulation effect of C-S-H gel could promote the solidification/stabilization of radionuclides of red mud in geopolymers. This research provides a perspective for the radiological safety of the red mud based geopolymers in construction materials.

Lightweight concrete is a building material used for better insulation and lower energy consumption. The material properties of lightweight concrete, such as compressive strength and thermal conductivity, are strongly affected by the characteristics of its aggregate, binder, and other concrete additions. This study aims to investigate the effects of different concrete additions on the performance of lightweight concrete. Six different materials were used as concrete additions: limestone powder, expanded clay (Liapor®), fine fly ash, fly ash, and fine and normal sand. For lightweight concrete specimens, expanded glass granulate, i.e., Liaver®, was used as a lightweight aggregate to clarify the effects of concrete addition type, with all specimens designed so as to have a density between 800 and 950 kg/m3. The effects of different concrete additions on the characteristics and properties of lightweight concrete were investigated using several approaches; X-ray micro-computed tomography ( μ -CT) was adopted to examine microstructural characteristics, with both the mechanical and thermal properties of the materials being measured using experimental tools. Numerical analysis was also conducted to validate the performance of the materials. The results show that supplementary materials can improve the performance of lightweight concrete with regard to both compressive strength and thermal conductivity.

In this paper, ecological masonry mortars as a new building material are design, using a mix of calcium lime and Portland cement as binder, together with steelmaking waste aggregate (Electric Arc Furnace Slag and Ladle Furnace Slag), in substitution of natural aggregate and, subsequently a comparative study was made using mathematical models. To do so, different reference mortar types were prepared with various proportions of calcium lime CL-90-S and Portland Cement CEM I 42.5 R as binder, together with a natural siliceous aggregate. Subsequently, and separately, the natural siliceous aggregate (NA) was progressively substituted by LF and EAF slags. The mixtures designed were analyzed in the laboratory through characterization tests (European Standard), and a comparative study was made with the reference mortars. Surface Response Methodology (RSM) was applied to test whether the mathematical model could acceptably predict the behaviours of these types of mortars, analytical process that allow predicting the behaviour of a material without having to complete the entire series of necessary laboratory tests. Comparing the results obtained in the laboratory and those estimated through mathematical models RSM of each of the properties, it can be affirmed that the methods of mathematical prediction were useful for the study of these ecological mortars for use in construction.

The use of woodchips of local origin for heating purposes is a diffused practice in some areas, like northern Italian alpine and sub-alpine zones, where large woods and forests extensions occur. In recent years, many thermal plants producing energy using woodchips as fuel have been constructed, supplying single edifices and delivering heated water to small communities through district heating. Unfortunately, due to the Chernobyl fall-out, particularly relevant in many mountain areas of northern Italy, woodchips of local origin are often contaminated with relevant 137Cs traces: therefore, the woodchips burning aimed at water heating produces ashes in which the 137Cs activity concentration is highly enriched with respect to that of the raw material. Typical activity concentrations of 137Cs in such ashes span a range from a few hundreds to several thousands Bq/kg. These combustion ashes are subject to different fates, according to reuse opportunities and law restrictions (not referred to the radiological aspects). Landfill disposal is the most common general option, together with the use in compost production plants and concrete factories. In this paper, we focused in particular to the use of concrete containing highly contaminated ashes, being considered as the most relevant from the radioprotection point of view. Therefore, some evaluations of the public exposure to radiations coming from concrete utilized as building material and containing woodchip ashes with high radioactivity levels (specifically 137Cs and 40K) have been done. The dose estimates for a person living in a house built with “contaminated” concrete were made using both standardized gamma radiation exposure indices and simulation models. The results are presented and discussed. Finally, a new formulation of the activity concentration index I is proposed for a safe and radioprotection sound use of building material containing woodchip ashes.

This paper presents fundamental information on the utlization of mosaic sludge waste from industrial mosaic activities into building materials. The study greatly benefits solid waste management and industries that produce waste with high heavy metal concentration by providing insights on ways to dispose waste by minimizing heavy metal leaching potential whilst providing a new formulation of low-cost and environmentally friendly building materials. Therefore, an alternative disposal method is to incorporate mosaic waste such as bodymill sludge (BS) and polishing sludge (PS) into fired clay brick. The bricks were incorporated with different percentages (0%, 1%, 5%, 10%, 20% and 30% by weight) of sludge waste and fired at 1050 °C (0.7 °C/min heating rates). The optimization results showed that the incorporation of up to 30% of mosaic sludge into fired clay bricks is capable of improving its physical and mechanical properties. Moreover, the incorporation of mosaic sludge waste into clay bricks has a positive effect on firing shrinkage, density and compressive strength. However, a decreased performance was reported for certain aspects. Hence, this study demonstrated that BS and PS can be alternative low-cost and environmentally friendly which can be used to improve the physical and mechanical properties of fired clay bricks.

Wood is an ideal building material as it is renewable and green. However, low dimensional stability and durability might restrict its usage in structural application. Therefore, modification is needed to improve the aforementioned issues. As an environmentally friendly wood modification method, heat treatment of wood using oil as a heating medium has brought to researcher’s attention to the fact that it might serve as an excellent treatment procedure in treating wood. This paper presents a review about the effects of oil heat treatment on the properties of wood such as colour stability, dimensional stability, mechanical strength and durability against termites and fungi as well as its potential to be used as construction and building materials. The pros and cons of using oil as a heating medium in wood treatment are discussed. This review shows discrepancies between the treatment methods or procedures and its resultant findings. Moreover, the effectiveness of the treatment is governed by several factors such as the type of oils used and wood species. The objective of the present paper is to conduct a review of the published literatures regarding the properties of wood modified by oil heat treatment and the results obtained were compared systematically.

The red mud waste generated from the alumina refining industry, which remains high alkalinity and problematic pollutants, is occupying considerable land resource and causing significant environmental problems worldwide. Instead of landfills, the utilization of the red mud waste as a substitution of mineral filler in asphalt pavement mixtures has been investigated in this study. The physical and chemical properties of the red mud waste were first characterized. The experimental tests including softening point, penetration, dynamic shear rheometer (DSR) and multiple stress creep recovery (MSCR) were then conducted to evaluate the properties of asphalt mastic. Based on the results on leaching toxicity and radioactivity, the red mud waste had no risk to be used as a building material. Moreover, the addition of red mud waste can improve the stiffness and elasticity of asphalt mastic. The increased rutting parameter and the decreased accumulated creep strain were further found, especially the Sintering RM. In addition, the Sintering RM had the capability to improve the elastic recovery of asphalt mastic, while the Bayer RM had limited contribution to this behavior. Consequently, the red mud waste can be concerned as a secondary resource to replace the natural mineral filler for asphalt pavements.

The increasing demand for environmental sustainability has prompted a growth in the production and implementation of energy efficient building materials. The use of phase change materials (PCMs) in buildings has proven to be an effective way of improving thermal regulation in buildings. However, the effectiveness of various PCMs has not yet been quantitatively assessed to identify which are superior. This paper conducted a critical review on PCMs and incorporation methods, and developed a novel ranking system based on the literature to assess and identify superior PCMs with respect to their thermal performance and economic efficiency. Initially, 24 potential PCMs were selected based on appropriate melting temperature and adequate heat of fusion values for building applications. Having taken the technical and environmental considerations into account, 20 PCMs (four were removed from the initial selection) were evaluated using the developed ranking system for their use in concrete. The salt hydrate eutectic of calcium chloride hexahydrate and magnesium chloride hexahydrate was found to perform the best based on the ranking results. To examine the viability of PCM-concrete as a thermally efficient building material, an economic and environmental case study evaluation has also been undertaken on its use in a typical New South Wales home. It was found that the payback period on the capital investment of the material was much less than the lifetime of the building, indicating that the technology is financially viable. Over a fifty year lifespan, the home would reduce a minimum of 28 tonnes of carbon dioxide emissions. Therefore, this technology could help Australia reach its 2030 greenhouse gas emissions reduction target.

Earth is a traditional building material used through History in many areas around the world. Nowadays, there is also a significant revival of its use because of its ecological value and architectural performance. However, there is still a lack of knowledge about its actual mechanical behavior. This paper is aimed at providing experimental data for the development of consistent methodologies for the characterization of this building material. Compression tests of prismatic, cubic and cylindrical specimens were carried out. The compressive strength, Young modulus and the stress-strain constitutive law are obtained and analyzed. The paper shows that the Unconfined Compression Strength of the material should not be obtained by applying existing correction factors for other materials. The paper also analyzes the meaning and usefulness of different estimates of the Young modulus. Finally, the paper proposes a simplified method for estimating stress-strain relationships from the compressive strength and its corresponding strain of tested samples by using reference normalized curves.

Serpentinites are rocks commonly used in construction. They have a very complex origin and multiple factors can influence their behaviour once placed in a building. These include the carbonation process that occurs naturally in these rocks. This process causes transformations of the serpentinite minerals (hydrated magnesium silicates) into carbonates, which affect their properties as building material. In the south of Spain, serpentinites have traditionally been used from two areas: Sierra Nevada (Granada), starting from the thirteenth century and the Sierra de los Filabres (Almeria). More recently, the latter are extracted together with the “White Macael” marble. They show variable carbonation state which is reflected in different properties even between very close outcrops. Their mineralogy, geochemical composition, and main technological characteristics were determined in accordance with the different UNE-EN Standards for use in the building industry. According to the results obtained, the process of carbonation in serpentinites affects their properties for construction and building materials. This process produces increased bulk density and decreased water accessible porosity, water absorption under atmospheric pressure, and water absorption coefficient by capillarity. Carbonation also leads to increased velocity of ultrasonic p-waves. The uniaxial compressive strength displays low values compared with the other samples. The values obtained for flexural strength are similar, or slightly lower, compared to the non-carbonated serpentinite. Knoop microhardness increases with carbonation. The results of our study can improve efficiency, productivity, and competitiveness in the use of serpentinites in the building industry.

LECA is the abbreviation of lightweight expanded clay aggregate. LECA is produced from special plastic clay with no or very little content of lime. The clay is dried, heated and burned in rotary kilns at 1100–1300 °C. LECA is porous ceramic product with a uniform pore structure with almost potato shape or round shape due to the kiln circular movement. The abundant numbers of small, air-filled cavities in LECA give its lightweight, thermal as well as sound isolation characterizes. In this article, the earlier studies which focused on using LECA as a part of building materials in traditional cementitious materials, as well as inorganic polymers (geopolymers), have been briefed. Furthermore, various materials which added to modify some properties of LECA concrete and mortar have been briefed and reported. The main findings of this review are the incorporation of LECA in the matrix increased its workability, decreased density, decreased mechanical strength, decreased freeze/thaw resistance, increased water absorption, decreased chloride penetration resistance, but increased thermal insulation and fire resistance.

Portland cement concrete is a major construction and building material used all over the world. It is a composite material comprising Portland cement, coarse aggregate, fine aggregate, and water. But its increased use in construction is exhausting natural resources used in its production, making it necessary to find alternative materials. One potential method is to use sea sand as fine aggregate to produce fly ash based geopolymer concrete. In this paper, the mechanical properties of geopolymer concrete prepared with sea sand as the fine aggregate, and the corrosion of steel bar embedded in the concrete subjected to accelerated corrosion tests, were investigated. The test data revealed that for sea sand based geopolymer concrete, the compressive strength reached high values at an alkaline to fly ash ratio of 0.35–0.45. The geopolymer concrete exhibited highcompressive strength with a low aggregate to fly ash ratio. Also, there was an increase in compressive strength when the Si/Al ratio changed from 1.16 to 1.67. Furthermore, very little difference was observed between the mechanical properties of geopolymer concrete using sea sand, and river sand. Measurements of the corrosion of steel bar using a half-cell potential survey indicated that the steel in geopolymer concrete with sea sand was attacked and corroded like normal concrete. However, the potential of steel bar in geopolymer concrete was higher than in Portland cement concrete.

The growing environmental awareness promotes the research of greener and more sustainable materials for their use in building materials. Polyolefin-based wood plastic composites (WPCs) have attracted the attention of researchers in the last decades mainly due to their improved mechanical properties, low weight and low cost. On the other hand, rapeseed is one of the most extended harvests in the world and their production is expected to increase in the next years, according to FAO (Food and Agriculture Organization). Rapeseed is mainly used for the production of biodiesel, and moving from an oil-based economy to a bio-based economy will presumably involve increases of rapeseed production. Its harvest produces high amount of agroforestry residue in the shape of integral stems which can be exploited as polymer reinforcing element, although very little information is found in the literature in this respect. In this work, the viability of rapeseed sawdust reinforced polypropylene copolymer composites was analysed regarding its mechanical tensile strength. Besides, the coupling agent percentage to ensure the best performance was also studied. The tensile strength of the produced composites has been modelled using well-known micromechanical models which allow the determination of the fibre and matrix contributions to the composite strength. The results showed that competitive green composite materials can be obtained using a byproduct of rapeseed harvesting.

The construction industry has been responsible for plaguing the environment due to ecological imbalance caused during the extraction and production of building materials. To make this production of construction materials cleaner, the dependency on natural resources has to be reduced. With this aim, marble powder which is a waste product generated during cutting and shaping of marble blocks has been evaluated as a replacement of conventional river sand in cement mortars. For this, four different mix proportions of mortars were evaluated in terms of workability, drying shrinkage, compressive strength, bond and adhesive strengths, density, water absorption and dynamic Young’s modulus. Results show that mortar mixes with 20% substitution of river sand by marble powder can be used for masonry and rendering purposes. Such mortars have a distinctively dense microstructure which is a consequence of reduced water requirement and formation of superior quality of hydration products. These were confirmed by scanning electron microscope, thermogravimetric analysis and Fourier transform infrared spectroscopy techniques. Hence, by replacing sand to the tune of 20% by marble powder, would enable the construction industry to reduce their dependency on river sand. Additionally, by utilizing this non-biodegradable marble waste as a building material, would reduce the burden on landfills and therefore help the marble stone industry to be more sustainable.

For the performance of wood as a building material, its dimensional changes in response to alterations of relative humidity are commonly perceived as an adverse effect. Recently, this material inherent property has been proposed to be utilized in a smart way. Employing the bilayer principle, controlled and reversible shape changes in response to changes of relative humidity were demonstrated. Wood naturally inherits a unique combination of material properties specifically suitable for large-scale shape-changing parts. While being environmentally responsive, it offers high mechanical stiffness throughout shape-change, ease of machining and working, and sustainable availability in large sizes and quantities. In this study, we demonstrate design principles for achieving a range of shape changing patterns such as uni- and bi-directional surface curvature of wood and wood-hybrid bilayers with both negative (hyperboloid curvature) and positive Gaussian curvature (spherical curvature). In parallel, we have developed suitable joints to join multiple elements to facilitate upscaling in length and width while maintaining shape-change. The ability to design and control the type and magnitude of curvature for specific sizes, shapes, and aspect ratios open the opportunity for a new class of large-scale weather responsive elements and self-forming building components.

The demolition process of a historical brick masonry building in St. Petersburg, Russia was observed as a case study and research was conducted on the possibility of reusing the resultant debris, which was composed of high quality brick masonry, as new building material. Therefore, samples from the demolition debris, i.e. brick, mortar and wall pieces were collected and tested for their mechanical properties, according to Russian standards, when available, and according to International Standards for the rest. The results for the compression test of brick and mortar separately as well as wall prisms indicated that their strength was still higher than standard limits, therefore, these wall pieces could be reused under appropriate conditions. Additionally, the bed mortar was tested under shear loads in order to understand if the jointing was still reliable or not. Eurococe 6 (Eurocode 6: Design of masonry structures – Part 1–1: General Rules for Reinforced and Unreinforced Masonry Structures, (2005)) defines a reference table for comparison, which showed that the shear resistance obtained from the wall prisms was also reliable.

Concrete is the most consumable building material in the world. Marine aggregates are the natural sand and gravels available in the sea or dredged from seabed. Contents of chloride, sulphate and shell in the marine aggregates can influence the properties of concrete and corresponding performance of the concrete structures. However, the limitations of chloride, sulphate and shell contents are set as different threshold values in different countries and/or regions. Some of them are inconsistent or puzzling for user. This paper presents a comprehensive review on the limit values of these contents used in different countries and provides a better understanding on the rationale behind these limit values thorough analysis on the limits of chloride, sulphate and shell content in marine fine aggregates for concrete. Except discussion, in this paper, an experimental study was carried out to evaluate the corrosion of reinforcing steel in concrete mixed with DMS as well. The experimental results of corrosion potential and corrosion current density showed that the rebar in DMS concrete should be safe from corrosion when the chloride content in DMS is less than 0.18% or the total chloride content in concrete is less than 0.34%. This study can contribute to fill the knowledge gap on concrete applications on dredged marine sand (DMS) and relative research.

Moisture has a significant influence on the mechanical and physical properties and on the biological durability of wood and wood based materials. As plywood is commonly used as a building material for outdoor applications knowledge regarding its moisture behaviour is of utmost importance. The aim of this research is to model water accumulation in plywood panels in terms of their basic characteristics and in-service moisture conditions. Therefore, moisture dynamics of 29 uncoated plywood types consisting of different wood species, adhesives and layering were evaluated using a simple laboratory water floating test and an outdoor continuous moisture measurement set-up. A significant correlation was found between laboratory and field test results. By means of regression analysis the material characteristics affecting the moisture dynamics of plywood were evaluated. The most influential parameters were wood species, glue type and thickness of the top veneer. Limit values for the water left in the plywood specimen after 72 h absorption and subsequent 72 h desorption, the residual moisture content (rm72), were calculated as to develop a classification tool for plywood. Based on such a classification tool some recommendations for uncoated plywood regarding end use and service life were drafted. Enhanced performance should be obtained by means of wood preservation or by reducing its residual moisture by applying a coating or by an optimal selection of adhesive, wood species and top veneer thickness.

Hemp concrete is a sustainable material with low embodied energy. However, its development as a building material requires a better evaluation of its moisture-thermal buffering abilities behavior, which are known to strongly depend on the amount of water contained in wall pores and its evolution. In this context, the aim of this paper is to study the experimental determination of sorption-desorption curves of hemp concretes following two methods and at two temperatures (23 °C and 40 °C). The former considers the total sorption-desorption loop, from the dried state to a relative humidity of 85%, while the second one is based on partial relative humidity cycles between 23% and 85%. At first, the difference between the curves obtained through these two methods were analysed. They were then implemented in a simple hygrothermal model to simulate dynamic hygroscopic and hygrothermal loadings. The comparison between the theoretical calculations and the experimental results eventually allows to scan which of these relations is more representative of the real dynamic behaviour of the tested hemp concretes.

The paper concerns the role of cellulose reinforcements in overall mechanical toughness of fiber concrete panels applied as facade building material. The results of mechanical tests performed on specimens in as delivered state as well as on specimens which underwent the procedure of destruction of internal fiber network structure due to pyrolysis are presented. The results of mechanical tests let the authors to calculate the work of fracture for six different mechanical conditions. Moreover the analysis of registered Acoustic Emission (AE) signal had revealed that the investigated process of destruction begins with the brittle crack generation and growth while major damages of reinforcement system appears in later phase of the process.

Natural rock is a very common building material, and its stability plays an important role in the safety and durability of tunnels, rock slopes, and other projects. However, tunnels and other underground projects often face the threat of disasters such as fires, and during their service, the surrounding rocks are also subject to erosion by acidic groundwater. Therefore, it is of great engineering significance to study the damage of the surrounding rocks under the threat of fire and acid groundwater. In this study, the variations in chromatic aberration, mass, P-wave velocity, porosity, thermal conductivity, and tensile strength of granite, sandstone, and marble induced by high temperature and chemical erosion are investigated from room temperature to 1000 °C. The results show that the rock materials exhibit different degrees of variation in physical and mechanical properties under the effect of high temperatures and acidic solution corrosion. Then, according to the variation of physical and mechanical properties, the formation mechanism of damage is discussed and the damage process verified by the deterioration of mechanical properties. For rocks heated to different temperatures and eroded by acid solution, the main reason for damage is the increase of cracks which destroy the structure and weaken the bonding between particles.

Rice husks ash was previously shown as a raw material for the foamed silicates production. This article is devoted to the use of the foamed silicates as an aggregate for the manufacture of lightweight cellular clay bricks. The coalescence of the foamed silicate structure inside a ceramic matrix leads to obtaining cellular lightweight ceramics in the process of firing. The present study has shown that on decreasing the ceramic brick density while using the foamed silicate filler the mechanical strength is not significantly decreased as opposed to the bricks with inert fillers. This effect is explained by obtaining a high strength glass layer on the inside surface of the cells. The lightweight cellular bricks demonstrate good heat insulation properties. Using rice husks ash as a raw for foamed granulated silicates in the manufacture of lightweight ceramic bricks not only solves the problem of rice husks as a large-tonnage waste, but also provides an environment-friendly building material with strength and heat insulation.

With the growing environmental impact related to the production, disposal, and recycling of synthetic fiber based polymeric matrix composites, environmentally friendly composites have been developed using materials based on natural resources. Of late, the disposal of agro-waste from industrial crops is another serious concern in developing countries. Based on the availability of agro-wastes, its usage for the development of sustainable composite materials is on the rise which constitutes a very interesting option for the construction industry. However, the water uptake characteristic of these natural fibers is established to be the most critical factor for the progressive deterioration of resultant composites’ properties over time. Present review article attempts to comprehensively report studies related to water absorption properties of agricultural fiber reinforced polymer composites. This study is divided into three sections: The first section highlights the water absorption mechanism including the experimental measurement and prediction using Fickian modelling. The second part outlines the experimental results of water absorption capacity for various composites with different types of thermosets, thermoplastics and agro-wastes. The last section analyses the potentiality of agro-waste materials to partly replace the conventional composites in building material research. The impact of water absorption on the mechanical properties of composites is also demonstrated. The literature survey compares the moisture/water content level of previous findings with the existing wood-based products in service and the established standard requirement for industrial building materials. This review article will provide a comprehensive data source for further research in this topic to explore the application of agricultural fiber-reinforced polymer composites as cheap, primary building construction materials.

Due to its reliability, strength, and ease of access, bamboo has become an attractive material for engineering applications. However, heterogeneous properties and durability issues still hinder the widespread use of bamboo as a building material. Thermo-mechanical treatment is a method to decrease the heterogeneity of bamboo culms and enhance mechanical properties and durability, but it may negatively impact dimensional stability. The objective of this study was to achieve the minimum spring back, water absorption, and thickness swelling for densified bamboo. Accordingly, the behavior of bamboo samples subjected to different thermo-mechanical (TM) treatments using a two-step analysis was investigated. In the first step, the optimum TM treatment for achieving the highest critical densification degree (DD) without shear failure was determined. In the second step, the three key elements of dimensional stability were studied for this optimum case. According to the first step results, the maximum achievable DD in which no shear failure happens and the texture is not disturbed is about 43.6%, and it can be obtained at 200 °C with a compression rate of 2 mm/min. X-ray densitometry analysis confirmed that DD of around 50% achieved the highest value of density, 1.30 g.cm−3. The results of step 2 revealed that the lowest values of spring back, water absorption, and thickness swelling, 4.72%, 23.80%, and 17.70% respectively, for densified bamboo occur when the densification process is conducted at 200 °C and adopting a compression rate of 6.7 mm/min. In conclusion, by manipulating and optimizing process parameters, the dimensional stability and final quality of densified bamboo can be improved, opening new opportunities for this class of material.

The construction sector is the most energy consuming one in the world, and it has a significant ecological impact. Indeed, concrete manufacturing overuses natural resources such as sand or gravel, and the need to use alternative building materials is urgent. Choosing adequate building materials takes an important part in the success of a high environmental quality project. This suggests using new alternative solutions, based on recycled materials or waste. However, their use being relatively recent, these materials properties are not widely known and there is lack of information concerning their hygrothermal and mechanical behavior. In this context, the present work aims then to highlight the experimental characterization of hygric, thermal, physical and mechanical properties of a recycled expanded polystyrene mortar, which is a relatively new building material, generally used for its thermal performances. Indeed, a complete characterization campaign was elaborated in this work, allowing a precise determination of the main properties of the material. The experimental characterization also included a usual cement paste made of the same cement as a reference material, in order to evaluate the polystyrene adding impact on the measured hygrothermal properties. Different methods of sorption isotherms determination were presented, and a better attention was devoted to the sorption hysteresis phenomenon characterization. The macroscopic hygrothermal properties, such as water vapor permeability, thermal conductivity and thermal capacity were also investigated function of the temperature and water content evolution. Mechanical strength was also determined, and SEM observations were performed to study the morphology of the material. Experimental results show that expanded polystyrene mortar exhibits a good thermal conductivity and thermal capacity, and a higher water vapor permeability. These results provide data for better forecast on the prediction of the hygrothermal and mechanical behavior of such material.

Exposure to 222-Radon (Rn) usually occurs in closed environments as effect of the Rn exhaled from building materials, soil or water. While building materials provide a protection barrier to outdoor natural radiation (terrestrial and cosmic), their radionuclide composition could increase the indoor Rn exposure. In fact, the Rn exhalation of building materials is of great importance from the viewpoint of mitigation and public health in very specific conditions. This work presents the Rn exhalation rates of 40 building materials (concrete blocks, clay brick, granite and concrete samples) produced and used in Ecuador, as well as the effective dose for a reference dwelling. Rn concentration measurements were performed using the closed chamber method and a RAD7 equipment. The resulting Rn exhalation rates were found to be in the range from 0 to 7.83 Bq · m - 2 · h - 1 . The highest surface exhalation rate was detected in granite samples, while clay bricks show Rn exhalation below the minimum detection level ( 0.05 Bq · m - 2 · h - 1 ). In the reference dwelling, the effective dose rates caused by Rn exhalation from building material range from 0.019 up to 0.112 mSv / y . However, the effective dose rate depends on the exposure time and quantity of granite used. Our results could be of immediate help to choose suitable building materials to ensure a safe indoor environment for the dwellers.

Usually, the thermal insulation and flame retardancy of traditional building material are mutually exclusive. It is very challenging to make a material with both of these properties. In this study, a hollow glass microsphere based ultralight non-combustible thermal insulation foam (HGMs-TIF) with point-to-point binding structure was prepared using solvent evaporation method. Five samples were prepared with different mass ratios of hollow glass microspheres and phenolic resin. The results showed that as the mass proportion of HGMs increase from 60.6% to 88.5%, the thermal insulation as well as flame retardancy of composite is improved. Remarkably, the HGMs-TIF-01 which has the largest proportion of HGMs (88.5%) shows lowest thermal conductivity of 0.0452 W/(m∙K) and lowest gross heat of combustion of 2.844 MJ/kg, what implies it is a non-combustible material according to the National Standard of the People's Republic of China GB/T 8624-2019 (i.e. gross heat of combustion of the standard of class A2 is lower than 3 MJ/kg). Besides, the HGMs-TIF-01 also is a lightweight and high-strength material, which has a low density of 0.142 g/cm3 and a high compressive strength of 0.748 MPa. It is helpful for the further design of the non-combustible thermal insulation material.

In recent decades, CO2 emissions from concrete production account for 5% of the global total carbon emissions. At the same time, the amount of industrial waste is also increasing year by year. As a non-toxic and harmless industrial waste, copper slag (CS) has been a great concern for researchers as a type of building material in recent years. This paper mainly reviews the relevant literature published in the past decade; critically discusses the performance of CS and the influence of partial replacement of CS on performance; and performs a global analysis, pointing out the direction for the future research on CS concrete. To make the conclusion comprehensive and reliable, this paper has consulted more than 90 related studies. The fresh performance, mechanical property and durability of CS concrete are discussed from three aspects of particle size, replacement rate and replacement method. In conclusion, as a partial replacement of cement or aggregate in concrete, CS can appropriately improve the strength, chloride ion corrosion resistance, sulphate corrosion resistance, carbonation resistance and freezing–thawing resistance of concrete. On the basis of research that describes the durability and compressive strength of CS concrete, the particle size and replacement ratio of CS in concrete preparation should be below 10 mm and 40%, respectively. According to the environmental impact analysis, using CS as a partial substitute can improve the environmental impact, although the production process still needs to be improved. Global analysis of results indicates that the long-term mechanical properties and durability of CS concrete need to be further studied.

Currently, growing activities in the construction sector have resulted in a rapid depletion of natural resources for building material production. On the other hand, agricultural industries generate a huge amount of residues/by-products every year around the world creating environmental concerns since most of these residues are burnt or disposed to the landfill. However, several current studies have presented the potential application of agricultural wastes in building material production owing to good physical and mechanical properties. Moreover, utilisation of such waste materials can contribute to reducing environmental impacts by proving alternative waste management strategies worldwide. This paper reviews some of the nut shell wastes (Argan nut, Brazil nut, Cashew nut, Groundnut, Hazelnut, Pistachio, Shea nut and Walnut) for the production of three groups of materials i.e. brick, mortar and concrete. Different properties of brick, mortar and concrete when admixed with nut shell wastes are discussed and compared with related standards. The review of literature exhibited an obvious potential of the nut shell waste as a partial replacement of conventional materials since most of the developed materials comply with the standards. However, a lack of studies on durability and thermal properties is observed. Besides, existing studies are inadequate to ascertain the potentiality of these wastes for reuse in building materials production. Therefore, extensive research is required to enhance the existing knowledge in this domain to achieve sustainable objectives in the construction industry.

Foamed concrete is widely used as a highly energy-efficient building material. However, low-density foamed concrete requires increased amounts of Portland cement or steam curing to meet engineering requirements. This is due to inadequate compressive strength and long setting time of Portland cement. In this study, we investigate a method for preparing green, high strength, low-density foamed concrete, which is ready to use without the application of heat or pressure. First, a sulfoaluminate high-activity material (SHAM) was prepared using red mud, aluminum dust, flue gas desulfurization-gypsum, and carbide slag. The SHAM was used to produce ready-to-use low-density foamed concrete (RLFC). RLFC with a dry density of 615 kg/m3 had a compressive strength of 4.11 MPa and a thermal conductivity of 0.1638 W/m·K. Addition of 0.2 wt% hydroxypropyl methylcellulose (HPMC) as foam stabilizer, increased the compressive strength by 27.22% to 5.22 MPa, which was 3.48 times the compressive strength specified by the relevant Chinese standard (1.5 MPa). To further enhance the practicality, other solid wastes (limestone tailings and gold tailings) were blended with SHAM to prepare the RLFC. RLFC prepared from SHAM, limestone tailings, gold tailings, and HPMC in the match ratio of 54:6:40:0.11 (wt%) delivered dry density, compressive strength and thermal conductivity values of 612 kg/m3, 2.37 MPa and 0.1556 W/m·K, respectively. This study provides a low-cost and highly promising method for preparing low-density foamed concrete, which not only consumes a large amount of industrial solid waste but also avoids depletion of resources and generates profits.

During the past few years, the construction industry is looking to expand the use of ecological materials, in order to create environmentally friendly buildings, contributing to the sustainability of built environment and limiting the waste of energy. In this direction, earth is seriously reconsidered as a possible building material of extensive use. Additionally, earthen mortars are globally an extremely common type of contemporary and traditional mortar on account of the availability of earth material, its good thermal properties and low embodied energy. However, the main disadvantage of earthen mortars lays in their reduced resistance against water action. In the present paper, the use of natural hydraulic lime (NHL3.5) and ladle furnace slag (LFS) is investigated for the stabilization of earthen mortars, aiming to enhance their water resistance. Different mortar mixes, including stabilized and non-stabilized earthen mortars, are examined in relation to their chemical properties (thermal analysis, DTA/TG), microstructural characteristics (mercury intrusion porosimetry, water uptake tests), and mechanical properties (flexural and compressive strength tests, ultrasound pulse velocity measurements). Shrinkage of the different mortars is also monitored and assessed. Finally, the mortars are subjected to wetting-drying cycles to determine the effect of the stabilizing agents on the mortars’ resistance against water. The results show that both NHL3.5 and LFS, present an excellent stabilizing efficiency, enhancing earthen mortars’ resistance against water, while simultaneously improving their physico-chemical and mechanical characteristics.

Starch is a natural polymer which is commonly used as a cooking ingredient. The renewability and bio-degradability of starch has made it an interesting material for industrial applications, such as production of bioplastic. This paper introduces the application of corn starch in the production of a novel construction material, named CoRncrete. CoRncrete is formed by mixing corn starch with sand and water. The mixture appears to be self-compacting when wet. The mixture is poured in a mould and then heated in a microwave or an oven. This heating causes a gelatinisation process which results in a hardened material having compressive strength up to 26 MPa. The factors affecting the strength of hardened CoRncrete such as water content, sand aggregate size and heating procedure have been studied. The degradation and sustainability aspects of CoRncrete are elucidated and limitations in the potential application of this material are discussed.