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Mixing forest industrial by-products, wood chips, with cement to produce thermal insulation concrete can help reduce energy consumption associated with temperature control in buildings. However, wood chips-based concrete usually has low strength due to the incompatibility between wood chips and the widely used ordinary Portland cement (OPC). To address this issue, this study explored using belitic calcium sulfoaluminate (BCSA) cement to replace OPC to enhance the mechanical performance of wood chips-based thermal insulation concrete. The investigation includes the analysis of thermal properties, physical properties, unconfined compressive strength (UCS), hydration reaction, and carbon footprint analysis for mixtures. The findings show that the wood chips concrete achieved an average oven-dry bulk density of 803 kg/m3 and thermal conductivity of 0.237 W/mK, establishing it as a lightweight thermal insulation concrete. In addition, the UCS results highlight BCSA cement's superior compatibility with wood chips. When replacing OPC with BCSA cement, the one-day unconfined compressive strength (UCS) of wood chips concrete increased from 0.7 ± 0.0 MPa to 5.1 ± 0.0 MPa, and the 28-day UCS increased from 4.3 ± 0.2 MPa to 8.0 ± 0.4 MPa. The carbon footprint analysis showed that utilizing BCSA cement and wood chips to develop thermal insulation concrete can result in a negative net carbon footprint of −34 kg CO 2 per tonne of mixture. The results show that replacing OPC with BCSA cement in wood chips concrete can achieve higher mechanical performance, excellent thermal insulation properties, and a negative carbon footprint. • Thermal insulation concrete was developed with belitic calcium sulfoaluminate (BCSA) cement and wood chips. • BCSA cement significantly increased the strength of wood chips-based concrete. • BCSA cement showed better compatibility with wood chips than Portland cement. • Concrete developed with BCSA cement and wood chips has a negative carbon footprint. [ABSTRACT FROM AUTHOR]

The inferior mechanical strength and thermal resistance of foam concrete limited its application in thermal insulation engineering. This study focused on enhancing the mechanical strength and thermal resistance of foam concrete by incorporating glass lightweight microspheres (GLM) to partially replace foam. The roles of GLM in foam concrete were investigated through physical, mechanical, and thermal properties tests. The improvement mechanism behind the mechanical strength and thermal resistance was further revealed. Results indicated that the addition of GLM enhanced mechanical strength of foam concrete by promoting hydration reaction, optimizing pore structure, and improving GLM-paste interfaces. The mechanical strength of foam concrete with 20 % GLM increased by about 40 %. Moreover, GLM improved the residual compressive strength after exposure to 800°C, with an enhancement of 39.8 %. The inclusion of GLM reduced the risks of crack formation, densified the paste, and strengthened the foam wall due to its hollow structure, pozzolanic reactivity, melting and filling effects, and the phase transformation of additional C-S-H into well-packed wollastonite. Additionally, GLM with closed and isolated pores reduced the drying shrinkage and water absorption rate of foam concrete. The finding suggests that incorporating an appropriate amount of GLM can produce high-strength, low-density, and thermal-resistant foam concrete. • Using GLM to partially replace foam improved the performance of foam concrete. • Foam concrete with GLM had high strength of 23.6 MPa and density of 1100 kg/m3. • The introduction of GLM contributed to superior high-temperature resistance. • GLM improved pore structure, foam distribution, and pore wall of foam concrete. [ABSTRACT FROM AUTHOR]

Titanium dioxide hollow microspheres (HMS-TiO 2) were successfully synthesized through a sol-gel and subsequent high-temperature calcination method using a hard template. These microspheres exhibit an average particle size of about 13.66 μm and a shell layer thickness approximately 1.18 μm. Furthermore, the thermal insulation effect is evident in cementitious materials coated with an HMS-TiO 2 -based composite film. The maximum average near infrared (NIR) reflectance and thermal insulation temperature difference of these coated materials are 46.81 % and 9.3 ℃, respectively. Notably, the modified composite film displays excellent mechanical and impermeable properties when applied to the surface of cement mortar samples. These comprehensive results indicate that introducing HMS-TiO 2 with the synergy of structure and composition significantly enhances the thermal, mechanical, and durability properties of modified waterborne coatings on cement-based materials. This augmentation makes them well-suited for thermal insulation and heat preservation applications in building structures. • Micro-scale hollow TiO 2 was synthesized using a hard template method. • The synergy of structure and composition is crucial for cement coatings. • Hollow TiO 2 -based coatings show excellent thermal insulation properties on buildings. [ABSTRACT FROM AUTHOR]

The extensive mining of natural resources, such as sand, for the construction industry, poses a hazard to the environment. To preserve the environment, the researcher must thus take into account the use of industrial byproducts rather than natural materials. The use of sawdust (SD) produced by the wood industry in foam concretes (FC) has been investigated in this study. This study examined the physical, mechanical, thermal, microstructural and durability characteristics of FC containing SD as a replacement of silica sand (SS) in the rates of 0, 25, 50 and 100 %. Two different SD sizes of 0–4 mm (SD4) and 0–1 mm (SD1) were used in the fabrication of FC mixtures. Protein-based foam agent was used to create FC mixtures. Fourteen mixtures with a 0.6 water/binder (w/b) ratio were produced at two different cement contents of 400 kg/m3 and 500 kg/m3. The fresh, mechanical, physical, and sorptivity characteristics of the FC mixtures were investigated in relation to the impacts of cement dosage, SD size, and SD replacement levels of SS. Durability of FC against high temperature, sulfate attack and freeze-thaw cycles was assessed. Costs and CO 2 emissions from the blends were also assessed. The outcomes revealed that a 25 %SD1 integrated FC mixture with a cement content of 500 kg/m3 generated the highest 28-day compressive strength of 3.56 MPa with a 20 % strength loss as per the Ref.500 mixture. 17 % lower thermal conductivity was gained with the inclusion of 100 %SD4 as per the Ref.400 mixture. The mixture with 50 %SD4 and 400 kg/m3 cement dosage exhibited the best resistance to high temperature. The mixture with 25 %SD1 and 400 kg/m3 cement dosage showed the best frost resistance. SD incorporated mixtures showed better durability performance than the reference mixtures. • This study evaluated the sustainable use of different sizes of SD aggregates in eco-friendly FC. • Fresh, thermal, mechanical and microstructural properties of FC were studied. • Transport properties, cost investigation and environmental impact of FC mixtures were also investigated. • Durability performance for sorptivity, sulfate attack, high temperatures, and freeze-thaw cycles was also carried out. [ABSTRACT FROM AUTHOR]

The use of bio-based building materials is a sustainable opportunity to reduce the environmental footprint associated with the construction sector. The achievement of this objective is primely achieved through the valorisation of vegetable waste, resulting in a reduction in the use of primary source material and waste generation. Within the scope of this study, the focus is directed towards research concerning the thermal, acoustic, and fire behaviour properties of bio-based building materials. This study conducts a comprehensive bibliometric analysis encompassing all documents meeting these criteria within the Scopus database, spanning two decades, from 2003 to 2023. The comprehensive analysis covered a total of 1081 documents, which were analysed. This analysis furnishes insight into various facets, including the temporal evolution of publications, journals boasting the highest publication counts and impact, influential research areas, countries with substantial contributions and their collaborative patterns, noteworthy affiliations, prolific authors, and seminal documents, alongside recurrent keywords. The objective of this comprehensive study is to provide a detailed analysis of the documents published up to the present day, in order to identify research gaps and potential opportunities in this field, to assist new researchers interested in the subject. The analysis reveals that bio-based building materials have gained substantial attention over the past decade. With each passing year, the published documents have increased their impact and become more specific, underscoring the growing importance of this subject. This evolution has also fostered a broader network of researchers engaged in this field. However, it is noteworthy that the characterization of these materials focuses predominantly on their thermal properties, while research avenues related to acoustic and fire properties remain less explored and present opportunities for future investigation. • This study contributes to identify research gaps and potential opportunities in the field of bio-based building materials. • Studies in bio-based building materials have shown an annual growth of the 25% since 2014, being a topic on the rise. • France and China are the countries with the highest scientific publication on bio-based building materials. • Keywords play a crucial role in making visible the research within bio-based building materials. • "Thermal Conductivity" and "Thermal insulation" are the most repeated keywords in this field. [ABSTRACT FROM AUTHOR]

Using natural porous and fibrous materials for acoustic and thermal conditioning in the construction sector is a solution to achieve a comfort level in buildings. The novelty of this research work lies in employing agricultural and agro-industry waste to solve noise and thermal insulation problems. This study was conducted to investigate a multilayered panel made of fruit stones and coconut fibre from agro-industry waste. Acoustic absorption, and acoustic and thermal transmission, tests were run on four different fruit stone types, olive, cherry, apricot and peach, plus a coconut fibre layer. Although they are not structural elements, bending tests were run to ensure panels' structural integrity. Acoustic tests complied with the recommendations of Standards ISO 10534–2 and ASTM E 2611–09, based on the standing wave tube to obtain the acoustic absorption coefficient and sound transmission loss, respectively. Standard EN 12667 was considered for the thermal test to determine the thermal conductivity coefficient based on the hot plate method. The results show an average sound absorption coefficient above 0.5 and sound insulation over 25 dB within certain frequency ranges. The cherry panels had absorption values of around 0.7 and apricots had sound insulation values of up to 30 dB. Samples' thermal transmittance coefficient values were between 3.0 and 3.4 (W/m2K), which indicate panels' ability to provide thermal insulation. The cherry and olive panels obtained the lowest thermal conductivity (around 0.14 W/mK). The backing effect of the coconut fibre layer improves all the panels' acoustic absorption and thermal properties. [Display omitted] • These natural materials reduce the environmental impact and support a more sustainable construction industry. • Acoustic and thermal properties of multilayer panels composed of fruit stones and coconut fibres. • The panels made of the studied materials, have inherent strength and stiffness that allows them to be structurally stable. • The results show an average sound absorption above 0.5 and sound insulation above 25 dB in certain frequency ranges. [ABSTRACT FROM AUTHOR]

High-strength thermal insulation mortar, with its excellent mechanical properties and thermal insulation performance, is commonly used in building structure insulation and reinforcement renovations. In this study, vitrified microbeads and expanded perlite (EP) were used as thermal insulation materials to create high-strength thermal insulation mortar. The effects of the replacement percentage of these materials (50%, 65%, 75%, and 80%) on the density, water absorption, porosity, compressive and flexural strength, and thermal conductivity of the mortar were studied. The results show that increased replacement percentages of vitrified microbead (EP) led to a decrease in the density of the mortar and an increase in the water absorption rate and porosity. Furthermore, when the replacement percentages were increased, the compressive and flexural strength and the thermal conductivity of the mortar were reduced. Comparative analysis of the pore structure of high-strength thermal insulation mortar using scanning electron microscopy and digital microscope revealed the influence of vitrified microbead (EP) on the internal pore structure of high-strength thermal insulation mortar. The influence coefficient (η s) of volume replacement percentage of insulation materials was introduced using the Hamilton and Crosser models. Furthermore, the prediction model of thermal conductivity of high-strength thermal insulation mortar was established under different volume replacement percentages of vitrified microbead (EP). The calculated values of the model matched well with the measured values, with the ratios of the calculated values of the model to the experimental ones ranging from 0.85 to 1.15. • The physical, mechanical, and thermal conductive properties of mortar are found to be influenced by the amount of insulation. • The prediction model of thermal conductivity of high-strength thermal insulation mortar is established. [ABSTRACT FROM AUTHOR]

Recycled concrete powder (RCP) is a promising supplementary cementitious material, its application in thermal insulation materials is however very limited. In this study, the influence of RCP substitution on the properties of insulation mortars was investigated. The results showed that as the RCP content increased, the compressive strength and thermal conductivity of insulation mortars decreased by 39.8% and 16.8%, owing to the increasing volumes of porous paste and internal air voids. Note that the mortar containing a high content (50 wt%) of RCP struggled to meet the strength requirements of the specification. Therefore, CO 2 curing was further employed here to alleviate the strength loss and successfully increased the compressive strength by 11%∼38%. It was found that since the CaCO 3 particles formed and densified the microstructure (confirmed by the porosity test), the strength reduction derived from the RCP substitution was compensated for. Consequently, insulation mortars incorporating 50% RCP after CO 2 curing for 7 days exhibited satisfactory compressive strength (∼ 0.22 MPa) and relatively low thermal conductivity (∼ 0.048 W/(m∙K)). The mortars showed improved aesthetic appearance and excellent thermal insulation capacity in both hot and cold environments. This study proposed a successful approach to combining reutilization of RCP and CO 2 curing in insulation mortar generation, which effectively improved the sustainability of materials. • A novel and sustainable EPS insulation mortar is developed for energy-efficient buildings. • The synergistic influence of the RCP substitution and CO 2 curing duration is studied. • Remarkably low thermal conductivity is attained through the incorporation of RCP. • Excellent aesthetic appearance and thermal performance are achieved simultaneously. [ABSTRACT FROM AUTHOR]

A novel lightweight foamed cement-based electromagnetic wave (EMW) absorbing material (Density<0.5 g/cm3) is prepared using secondary aluminum ash (SAA) as a foaming agent and carbon black (CB) as an efficient EMW absorbent, providing a new way to recycle SAA. The pore structure parameters, reflection loss (RL), mechanical strength and thermal conductivity are systematically investigated. The experimental test results indicate that the pore structure of cement matrix prepared by SAA exhibits better EMW loss performance than those prepared by traditional foaming agent. The analysis of the pore structure images indicates that the average pore size is reduced, and pore size distribution shifts towards smaller sizes due to the addition of CB. Furthermore, the roundness of pores is increased due to the formation of more irregular pores. Increasing CB content and thickness can reduce RL, enhance absorbing performance at low frequencies, and broaden effective absorbing bandwidth (EAB). The absorbing performance was tested using the arch reflection method in the frequency range of 1.1–18 GHz, the excellent absorbing performance and the widest EAB (RL<−10 dB) reach −36.34 dB and 14.46 GHz, respectively, at a thickness of 4 cm. Benefiting from excellent pore structure, the foamed cement-based material also exhibits better mechanical strength, and good thermal insulation properties are maintained after adding CB. The compressive and flexural strength can reach 2.18 MPa and 1.02 MPa, respectively, while the thermal conductivity remains below 0.122 W/(m·K). • Lightweight cement-based absorber was firstly prepared using SAA as foaming agent. • The effect of CB on pore structure and EMW absorbing property is investigated. • EAB and minimum RL of the developed absorber reach 14.46 GHz and − 36.34 dB. • A new way to recycle SAA is provided. [ABSTRACT FROM AUTHOR]

In the field of material science, foaming agents common are commonly used for enhancing the thermal insulation and phase change materials (PCM) for heat storage. However, PCM tends to agglomerate in the cement slurry with the directly addition, presenting an obstacle to effective dispersion. Moreover, the addition of PCM leads to rapid defoaming. To overcome this issue, a novel nanoparticle-stabilized foam was designed in this study to create a three-component system that enhances the interaction of viscosity modifiers, surfactants, and foam stabilizers. The effect of cement density on thermal insulation was evaluated by analyzing thermal conductivity and heat transfer performance tests, as well as exploring the mechanical properties of the cement-based materials. Scanning electron microscope (SEM) images show that the foam designed in this study remarkably promotes the dispersion of PCM microcapsules, indicating the bridging interactions of foam in the cement paste. The result shows that the thermal conductivity of foam cement with 15 vol% PCM microcapsules drops from 0.11 W/m·k to 0.07 W/m·k compared to that without PCM addition, with a dry density around 600 kg / m 3. Furthermore, the specimens with the addition of PCM achieve the endothermic and exothermic peaks under experimental images. This discovery is of great significance to heat absorption ability of low-density concrete, where the addition of PCM leads to a slower foam bursting under the nanoparticle-reinforced foam system. The dispersion and connectivity of foams, as well as the physical characteristics of PCM, provide new perspectives for coexistence in a relatively stable system in this way. • Nanoparticle-stabilized foam remains stable within the cement slurry. • Stable foam contributes to the low thermal conductivity and superior insulation performance of foam cement. • The sustainable and environmentally friendly energy-saving effects of phase change materials microcapsules in foam cement. • A novel lightweight and eco-friendly cement with thermal regulation capabilities. [ABSTRACT FROM AUTHOR]

• Silica aerogel granules were replaced by quartz sand of 0 to 4.5 wt% to produce lightweight cement-based composite mortars. • SAG has increased the water absorption and porosity of the mortar, while reduced compressive strength and hardened density. • Pores increased with increase in aerogel, SAG tend to agglomerate, and pores accumulate around the aerogel particles. • SAG significantly decreased thermal conductivity from 0.772 to 0.155 W/mK. • SAG also reduced thermal diffusivity and heat storage, and increased specific heat. It has been discovered in recent years that the use of silica aerogel in cement-based materials contributes to the thermal insulation properties of the materials, and studies on this subject have gained importance. However, it was determined that the studies mostly remained at the level of the thermal conductivity coefficient and the main physical and mechanical properties of the materials. In this study, a comprehensive research was carried out with the replacement of micro-sized aerogel particles with quartz sand in different ratios (0, 1, 1.6, 2.4, 3.2, 4 and 4.5 wt%) in lightweight cement-based composite mortar (LCCM) combinations. Specifically, the effect of silica aerogel granules (SAG) on flowability, fresh and hardened densities, porosity, water absorption, compressive strength, macro/microstructural properties (by optic microscope, SEM, XRD analysis), thermal conductivity, specific heat, thermal diffusivity and heat storage capability of LCCMs were investigated. While SAG could increase the flowability (up to 8.4 %) at low using rates, it decreased it at higher rates. It is very effective in reducing fresh and hardened densities. However, it highly increased porosity and water absorption, and greatly decreased compressive strength. On the other hand, generally the poor interfacial properties of the cement matrix and the aerogel were moderately improved in this study. The lowest thermal conductivity was determined as 0.155 W/mK in the highest SAG usage. SAG increased specific heat, decreased thermal diffusivity and decreased heat storage capability of LCCMs up to 45.23 %, 63.49 % and 46.32 %, respectively. As a result of the study, aerogel has been identified as a very suitable material that can be used to highly improve thermal properties in LCCMs. [ABSTRACT FROM AUTHOR]

• Phenolic resin is used as an insulation modifier for geopolymer for the first time. • Phenolic resin can increase the porosity of fly ash geopolymer. • Phenolic resin can reduce the porosity of nanopores but increase more micropores. • Phenolic resin narrows the throat of the ink bottle pores. • An iterative method related thermal conductivity prediction method is proposed. Phenolic resin has been widely used owing to its excellent thermal insulation performance. However, the application of phenolic resin in the field of geopolymer remains unexplored. Here, the foamed fly ash geopolymer samples with high porosity were prepared using phenolic resin for the purpose of foaming materials. The thermal insulation properties of these samples were evaluated by Transient Plane Source Method, and the effect of phenolic resin on pore characteristics was investigated by Mercury Intrusion Porosimetry (MIP), aim to explore how phenolic resin affects the thermal conductivity by changing the pore characteristics of geopolymer. In addition, considering that the internal gas thermal conductivity of pores with different pore sizes is also different (Knudsen effect), in order to predict the thermal conductivity more accurately, this research proposes an iterative calculation method to establish a thermal conductivity model. The results show that phenolic resin can improve the thermal insulation effect of geopolymer, and the minimum thermal conductivity of the sample is 0.17 W/m·K. In addition, according to the test results of MIP, it can be found that phenolic resin mainly promotes the porosity of micron pores (>1 μm) whereas there is slight inhibition on nano pores (<1 μm), but the beneficial effect of the increase of micron-sized pores (>1 μm) on the thermal insulation performance of geopolymer is greater than the negative influence effect of the disappearance of nano pores. Moreover, according to the results of MIP, phenolic resin can narrow the throat in the pore of the ink bottle, limit the thermal convection of the gas between the pores, and reduce the thermal conductivity. Finally, the newly modified Russell model considering the Knudsen effect can effectively predict the thermal conductivity by using the experimental data. This study provides a new method to improve thermal insulation performance of geopolymers and offers a new building insulation product. [ABSTRACT FROM AUTHOR]

• Properties of alkali-excited fly ash aerogel foam concrete were studied. • The microstructure of alkali-excited fly ash aerogel foamed concrete was analyzed. • Test variable included aerogel particles, fly ash, foam and polypropylene fiber. • Developed concrete exhibited excellent thermal performance and mechanical strength. • Aerogel used in concrete had excellent thermal insulation performance. With increasing focus on low-carbon energy conservation and environmental protection, there is a need to consider all aspects of life in future developments. To meet the concept and requirements of energy conservation and environmental protection in the building industry, we have developed alkali-excited aerogel-foamed concrete that exhibits excellent thermal insulation performance and mechanical strength. The variables involved in its production include fly ash, foam, aerogels, and polypropylene fibres. In this study, the microstructure and mechanical and thermal properties of alkali-excited fly ash aerogel foam concrete was analysed. The results indicated that fly ash can replace a portion of the cement, resulting in a reduction in the thermal conductivity of the concrete. The addition of aerogels and foams to the concrete can significantly decrease its thermal conductivity. Specifically, when the aerogel content reaches 12 % and the foam content reaches 75 %, the thermal conductivity of the concrete decreases from 0.498 W/m·K to 0.183 W/m·K and 0.19 W/m·K, respectively. However, this decrease in thermal conductivity comes at a cost of approximately 50 % reduction in the flexural and compressive strengths of the concrete. The findings reveal that the aerogel has excellent thermal insulation performance similar to that of the foam, but it has little influence on the mechanical properties of the concrete. Additionally, an increase in the polypropylene fibre content significantly improves the mechanical properties of alkali-excited fly ash aerogel concrete, but the thermal properties of the concrete remain mostly unaffected. [ABSTRACT FROM AUTHOR]

• Mechanical and thermal properties of straw boards with high densities are studied. • Tensile strength prediction method of straw boards is proposed. • Correlation between thermal conductivity and density of straw boards is revealed. • Feasibility of using straw boards for load bearing and insulation is verified. • Wheat straw strand board is identified as transversely isotropic material. Straw is an environmentally friendly, cost-effective, and abundant raw material for building boards. To assess the feasibility of using straw boards in building envelops, such as being alternative sheathing panels in light-gauge steel-framed members, for instance, walls and floors, both the mechanical and thermal properties of straw boards with high densities were investigated. The straw boards involved in this study include five wheat straw strand boards (WSSB12, WSSB15, WSSB18, WSSB25, and WSSB30) and a paper straw board (PSB58) named with a combination of the respective board type and thickness. Among them, the WSSBs are a type of straw composite, while the PSB is an improved straw bale with sheathing paper, which is mainly for enhancing the board integrality. Moreover, the former is composed of smashed straw fibers and isocyanate resin and has higher densities, while the latter is without using any artificial binders. Mechanical properties, including compression, tension, and bending properties, were investigated by tests and a proposed prediction method of tensile strength. In the experimental studies of compression properties, the failure modes, characteristics of load-deformation curves, and the differences in material directivity were analyzed and discussed. The results show that the WSSBs were considered to be transverse isotropic material with brittle characteristics in the plane. Then, the experimental studies of bending properties were carried out, and the results show that the bending strength is less than the compressive strength for WSSBs, while the bending strength of PSB is greater than its compressive strength. And the bending elastic modulus and the compression elastic modulus are close for either the WSSBs or the PSB. Furthermore, finite element models of the bending test specimens using the user material subroutine UMAT were developed to predict the tensile strength f t , and the constraint checks were conducted. It is verified that the prediction results of f t are believable, and the prediction method proposed is feasible. For the thermal properties of straw boards, tests were performed using the temperature control box - heat flux meter method, and the thermal conductivity λ was mainly focused. It is found that a significant linear correlation exists between the density ρ and λ , and the proposed fitting formula can be used to predict the thermal conductivities of such materials. Finally, brief comparisons of the mechanical and thermal properties between the straw boards and the oriented strand boards (OSBs) were conducted, and the feasibility of applying straw boards in building envelops, such as alternative sheathing panels with load bearing and insulation demands was verified. This study contributes to popularizing the application of straw boards in engineering structures by a compromising consideration of mechanical and thermal properties, which plays a positive role in the development of green buildings. [ABSTRACT FROM AUTHOR]

• Cyclic loads applied on foam glass aggregates (FGA) at different compaction ratios. • FGA response under deviatoric stresses 25 kPa, 100 kPa, and 200 kPa was investigated. • Resilient modulus (M r) and accumulated plastic strain (ɛ acc) were measured. • Increasing the compaction ratio led to a significant decrease in ɛ acc values. • Revealed that FGA at 40% can be used in infrastructure base layer material. Foam glass aggregate (FGA) is considered as a lightweight and thermal insulation material. It has a wide granular size distribution nature that can influence the material's dynamic response when subjected to moving loads. Therefore, it is crucial to investigate the impact of different compaction ratios on the material's dynamic behavior. This study focused on examining the effects of varying compaction ratios (10%, 20%, 30%, and 40%) on dynamic parameters such as resilient stiffness (M r) and accumulated plastic strains (ɛ acc) of FGA. Uniaxial deviatoric stresses were applied to the material samples in a series to assess their influence on the material's behavior over multiple cycles. The results revealed the significant influence of increasing the compaction ratio to 40% on the material's behavior. At this compaction ratio, the ɛ acc decreased to approximately 71%, 69%, and 86% for deviatoric stresses of 25 kPa, 100 kPa, and 200 kPa, respectively, after subjecting the material to 40,000 cycles. The increase in recoverable strains resulting from the material's fragile property under higher compaction energy led to a decrease in the M r values of FGA samples as the compaction ratios increased. The lower boundary of M r values for FGA ranged from 102 MPa to 189 MPa, while the upper boundary ranged from 150 MPa to 219 MPa under the selected deviatoric stresses. Although the interpretation of the shakedown criterion limitations yielded varying ranges for the colocation of FGA samples, it was found that FGA samples compacted at 40% exhibited robust characteristics suitable for constructing road embankments. This can be beneficial for infrastructure applications due to their excellent lightweight and thermal insulation properties. [ABSTRACT FROM AUTHOR]

• Fully bio-sourced building insulation materials from rice straw and natural binders are developed. • A crosslinking method is proposed to prevent the water solubility issue. • The effect of fiber size, binder type and binder ratio on the hygrothermal properties is investigated. • Alginate-based composites shows more serious mold growth than chitosan-based composites. Conversion agricultural straws to building insulation materials has attracted great interest due to their good hygrothermal properties and low carbon footprint. In this study, fully bio-sourced composite materials were designed based on rice straw and natural binders. Sodium alginate and chitosan were used as the binders. A crosslinking method was proposed to prevent the water-soluble issue of the composites using sodium alginate as the binder. The influence of fiber size, binder type and binder ratio on the hygrothermal properties of the composite materials made of rice straw were investigated. It was found that all the materials are insulating with their thermal conductivity values between 0.038 and 0.047 W/(m⋅K). The alginate-based composites had the higher water vapor permeability and moisture sorption capacity than the chitosan-based composites. Larger fiber size and lower binder ratio resulted in lower thermal conductivity and higher water vapor permeability. However, fiber size and binder ratio had a negligible effect on moisture sorption capacity of the composite materials. Additionally, the mold growth was investigated by exposing the composite materials to severe conditions, i.e., 93% RH and 97% RH at 20 °C. Mold proliferation was found to be easier and quicker in the surface of alginate-based composites compared to the chitosan-based composites. [ABSTRACT FROM AUTHOR]

[Display omitted] • Expanded lightweight plates were prepared by combining expanded glass, expanded vermiculite, and expanded perlite particles with an innovative TEOS/MTMS sol-gel binder. • Expanded glass based plate exhibited the greatest compressive strength (7.04 ± 0.44 MPa) and the highest direct tensile strength (0.486 ± 0.04 MPa). • The long term water absorbency values of expanded perlite based plate was found to be 1.76 ± 0.1 v% in the 1st day and increased slightly to 9.96 ± 0.04 v% in the 28th day. • Thermal conductivity coefficient of expanded glass based plate performed the best result which was measured as 0.125 W/m.K at 25 °C. • NIR-reflective property of expanded glass based plate was recorded as 83.2 ± 0.5 %. • All inorganic-based plates exhibited high fire resistance performance (withstand temperatures of up to ∼900 °C for 30 min). Thermal insulation materials are a great solution to minimize energy consumption for construction applications. Especially, expanded inorganic lightweights are excellent candidates in terms of their low thermal conductivity and high fire resistance properties. Sol-gel type inorganic based binders are also useful chemical substances to combine lightweight particles. In current study, inorganic-based plates were developed by using expanded glass, expanded vermiculite, and expanded perlite particles with a novel tetraethoxysilan (TEOS)/methyltrimethoxysilane (MTMS) sol-gel binder. The chemical, physical, mechanical and thermal properties of the plates were examined comparatively to reveal the effect of expanded lightweight particle types in the plates. According to the experimental results, the compressive strength of the developed plates was between 7.04 ± 0.44 MPa and 3.15 ± 0.17 MPa whilst the direct tensile strength ranged from 0.486 ± 0.04 MPa and 0.079 ± 0.04 MPa, respectively. Furthermore, the long term water absorbency values of the plates on the 28th day varied between 9.96 ± 0.04 v% and 49.8 ± 0.8 v%. On the other hand, while the thermal conductivity coefficient of the plates at 25 °C ranged from 0.125 to 0.254 W/m.K, infrared reflectance properties were determined between 83.2 ± 0.5 % and 64.1 1.8 %. Besides, all inorganic-based plates exhibited high fire resistance performance (withstand temperatures of up to ∼900 °C for 30 min). The results demonstrated that utilizing expanded inorganic lightweight particles with TEOS/MTMS sol-gel binder could be a promising combination to construct energy saving insulating plates to overcome poor fire resistance properties of conventional organic materials. [ABSTRACT FROM AUTHOR]

• Part of water was pre-located in the lightweight aggregates (LWA) for producing HPLC. • The increasing amount of LWA decreased the density of HPLC significantly. • The water penetration and ion permeability of HPLC were very low. • The HPLC exhibited high structural efficiency and low thermal conductivity; • The dislocation of mixing water method enhanced the microhardness of the paste matrix. To prepare high-performance concrete, the mixing water was normally blended with the dry constituents directly, whereas in this study part of water was pre-located in the lightweight aggregates (LWA) for producing a high-performance lightweight concrete (HPLC). With the pre-location of water in the LWA, an extremely low w / b ratio paste (ultra high-performance composite) was resulted for producing HPLC. High-performance cement mortar (HPCM) was prepared with similar volumes of natural aggregates for comparison. Based on the initial spatial dislocation of mixing water in two systems, the physical, thermal and durability properties of high-performance cementitious composites were evaluated and compared. The results showed that the HPLC experienced delayed heat evolution when compared with that of the HPCM, while the cumulative heat output and degree of cement hydration of the two systems were similar. With the use of an increasing amount of LWA, the density of HPLC decreased significantly while the water penetration and ion permeability of HPLC were comparable to those of HPCM. More importantly, the HPLC exhibited a higher structural efficiency and much lower thermal conductivity than the HPCM. In addition to the pozzolanic reactivity and internal curing provided by the water-entrained LWA, the dislocation of mixing water method also enhanced the microhardness of the paste matrix, which contributed to the excellent performance of HPLC. [ABSTRACT FROM AUTHOR]

[Display omitted] • This research investigates the composites obtained from EP and camelina stalks. • Thermal, physical and mechanical properties of the new bio-composites were studied. • The thermal conductivity of the composites decreased with the addition of expanded perlite. • The water absorption, UPV and compressive strengths of the composites to which expanded perlite was added increased. • C45 and C45P5 composites can be used as an alternative to thermal insulation materials. • Thermal conductivity, unit weight, compressive strength and UPV decreased as the camelina ratio increased. Increasing urbanization has made lightweight construction materials with low thermal conductivity important. One of these materials, which has gained importance recently, is bio-composite materials consisting of agricultural wastes. The usability of camelina stalks, an agricultural waste, in the production of bio-composite has not been studied. The aim of this research is to develop new lightweight bio-composites with camelina stalks filled. For this, 11 composite mixtures using unsaturated polyester resin as the binder were created. Camelina stalks at 25, 30, 35, 40 and 45 % substitution ratios were used in half of 10 mixtures outside reference. Later, five more different mixtures by adding expanded perlite (EP) up to 5 % of the amount of camelina stalks in each mixture were produced. The physical, mechanical and thermal properties of the bio-composites produced with polyester binder were examined and the microstructure analysis was performed by SEM. The results showed that thermal conductivity, unit weight, compressive strength and ultrasonic pulse velocity (UPV) decreased as the ratio of the camelina stalks increased. The lowest thermal conductivity value was determined as 0.0842 W/(mK) in the 45 % camelina + 5 % EP filled specimen. The highest compressive strength value of the mixtures excluding the reference specimen was found to be 35.78 MPa in the 25 % camelina + 5 % EP-filled specimen. The addition of EP to the composites increased the water absorption, UPV and compressive strengths, but decreased the thermal conductivity. The results showed that camelina stalks can be used to produce sustainable bio-composites. [ABSTRACT FROM AUTHOR]

• To achieve the desired printability, the optimal replacement range for silica sand by aerogel in a cementitious mixture is 0–20% by volume. • The thermal conductivities of the SC and 3D printed specimens ranked in the order of 3DCP-X > SC > 3DCP-Y > 3DCP-Z, irrespective of aerogel content. • The weak bonding interfaces between adjacent filaments produce gaps, providing channels for heat to transfer in specimens 3DCP-X. • Under the same thermal and mechanical requirements, walls fabricated by AG-incorporated concrete are 7-cm thinner than traditional concrete walls. This study investigated the properties of fresh and hardened aerogel (AG)-incorporated concrete suitable for 3D concrete printing. After trial and error, it was found, that to achieve the desired printability, the optimal replacement range for silica sand by aerogel in a cementitious mixture is 0–20% by volume. The physical, mechanical, and thermal insulation properties of hardened concrete in three directions were studied, and the influence of anisotropy on these properties was investigated. The results showed that irrespective of the aerogel content, the compressive strength of the cast specimens (avg. 24.90 MPa in A20) was slightly higher than those of the 3D printed specimens, 3DCP-X (avg. 23.63 MPa in A20), 3DCP-Y (avg. 20.77 MPa in A20), and 3DCP-Z (avg. 20.40 MPa in A20). The thermal conductivity of the cast and printed specimens decreased gradually with an increase in the aerogel content. Relative to that of the cast specimens (0.330 W/(m·K) in A20), the thermal conductivity of specimens 3DCP-X (0.405 W/(m·K) in A20) was slightly higher, while those of 3DCP-Y (0.320 W/(m·K) in A20) and 3DCP-Z (0.306 W/(m·K) in A20) were lower. A thermal insulation wall (400 mm × 200 mm × 600 mm) with hollow structures was printed using the AG-incorporated concrete. To satisfy the same thermal and mechanical requirements, walls fabricated using AG-incorporated concrete can be 7 cm thinner than traditional concrete walls. The mechanism for the heat transfer of AG-incorporated concrete in three directions was examined as well. [ABSTRACT FROM AUTHOR]

• Raw and treated doum fibers were used to produce compressed earth brick (CEB). • The mechanical and thermophysical properties of CEB are investigated. • The reinforcement by doum fibers decreases density and increases water absorption. • The addition of fibers decreases thermal conductivity and compressive strength. • The use of doum fibers promises the production of an ecological building material. This work investigates the physical and mechanical properties of compressed earth brick (CEB) reinforced with raw doum fibers (RDF) and treated doum fibers (TDF). Firstly, the raw materials were characterized. Then CEB reinforced by fibers varying from 0 to 2% by mass were elaborated. The addition of RDF and TDF reduces the compressive strength by 25% and 35% respectively. However, the inclusion of fibers improves the thermal insulation of CEB and decreases its density of about 16%. The research finding indicates also that the capillarity absorption increases with the increase of fiber content. These results indicated that the use of doum fibers to produce ecological building materials has a promising future. [ABSTRACT FROM AUTHOR]

• Layered samples of thermal mortars have lower A w than standard prism samples. • The s d of paints can depend on the substrate (singular mortar VS composite sample). • Recommended in technical sheets: s d of complete systems, and also A w for external ones. • Thermal mortars with cork/EPS: lower λ than declared, still of interest in temperate climates. • Thermal mortars: strong dependency of λ on water content. Among thermal insulation solutions for historic walls, thermal renders and plasters appear to be a very feasible option. Thus, this work analyses commercially available thermal mortars suitable for the scope. An extensive experimental campaign showed that testing single materials only, which is the standard requirement for thermal mortar-based systems, is in fact not sufficient for understanding the potential impact of the intervention on walls: whole-systems should also be examined. This study provides a detailedcharacterization of materials and systems, useful as a database for forthcoming investigations on compatibility and efficacy for application on historic walls, via numerical hygrothermal simulations. [ABSTRACT FROM AUTHOR]