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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]

• Corn stalk concrete using MPC and OPC were studied. • Effect of temperature on thermal properties of two biocomposites was studied. • MPC binder is more suitable for producing plant aggregate concrete. This paper reports a comparative investigation of two new corn stalk (CS) biocomposites based on magnesium phosphate cement (MPC) and ordinary Portland cement (OPC). Two composites with identical corn stalk contents and different binders were prepared. The porosity, water absorption, drying kinetics, compressive strength and thermal properties of the biocomposites were measured. The experimental results show that the lower open porosity of the CS-MPC concrete results in lower water absorption and weaker evaporation performance. In addition, the open porosity and closed porosity play important roles in the effect of temperature on the thermal properties in the dry state and moist state. The dry and moist thermal conductivities of CS-MPC concrete is slightly higher than that of the CS-OPC concrete, which can meet the thermal insulation requirements. Due to the excellent bonding between the MPC binder and corn stalk plant aggregates, the compressive strength of CS-MPC concrete is significantly higher than that of CS-OPC concrete. These results indicate that MPC binder is more suitable for producing plant aggregate concrete. [ABSTRACT FROM AUTHOR]

• The technical feasibility for manufacturing fired clay bricks by adding vine shoots has been tested. • The influence of particle size and percentage of vine shoot replacement has been discussed. • The percentage of vine shoot replacement highly impacts on mechanical and thermal properties. • The influence of particle size on mechanical properties increases by increasing percentage of additive. • The proposal environmental impact seems to be positive but further assessments must be conducted. For decades, the construction industry has focused on developing new materials to minimise environmental impact and improve building insulation envelopes. The use of certain wastes as additives for construction materials (e.g. concrete, clay, steel) has been shown to be a feasible alternative that may improve both the current waste management strategy and the properties of construction materials. Among others, the fired clay brick (FCB) industry has been highlighted as an optimal sector for incorporating such residues, due to the large amount of mass flow involved, the use of firing temperatures above 900 °C and the observed positive effects of FCB thermal conductivity (TC) when organic residues are added. Although the properties of fired clay are closely related to the firing curves and the mineral and chemical composition of raw materials, the effect of particle size is also a key factor that directly impacts on the economic and technical feasibility. This paper therefore assesses the addition of wood chips from pruned grapevine shoots as an additive for manufacturing FCBs, and considers three particle sizes (up to 0.5 mm, above 1.5 mm and between 0.5 and 1.5 mm) and variations in the added percentage on a dry basis. Several samples were tested in order to determine the mechanical and thermal behaviour of FCBs, and it was concluded that the maximum of 10% wood chip content is limited by both the compressive strength values and the water absorption. At this percentage, TC is reduced by up to 50%. The particle size seems to have no effect on the thermal properties, but gives rise to significant variations in terms of the mechanical response. [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]

• This study proposes ply-lam CLT with domestic plywood as the core material of CLT. • The thermal conductivities of ply-lam CLT in the radial was lowest at 0.104 W/m K. • The ply-lam CLT walls had lower thermal bridges than wood frame structure walls. • The ply-lam CLT walls with exterior insulation had lower thermal bridges. • The connection method using STS was able to maintain excellent insulation performance. Cross-laminated timber (CLT), developed in Europe for the utilization of low-grade wood, is an engineered wood product (EWP) with high carbon storage and low carbon emissions. CLT wooden houses have advantages such as reduction of greenhouse gases, shortening of construction period through precast and modular construction, improved of insulation performance and airtight performance, the realization of the high-rise wooden house. In this study, ply-laminate cross-laminated timber (ply-lam CLT) was prepared using domestic plywood as the core material of CLT, and the thermal properties and heat transfer performance of ply-lam CLT were analyzed. The thermal conductivities of the ply-lam CLT in the radial, tangential, and longitudinal directions were 0.104 W/(m K), 0.111 W/(m K), and 0.122 W/(m K), respectively. The results of the heat transfer analysis through ISO 10211 indicated that the ply-lam CLT walls had lower thermal bridges than wood frame structure walls. Moreover, the ply-lam CLT walls with exterior insulation had lower thermal bridges. In addition, the self-tapping screw (STS) joining method on all connections was able to maintain excellent insulation performance because of low thermal transmittance coefficient. In addition, it should be noted that the STS applied from inside overlapped with the geometric thermal bridges. [ABSTRACT FROM AUTHOR]

Highlights • Thermal insulating properties of Geopolymer mortar and simwool fibre blanket. • Degradation in structural response of CFRP wrapped concrete due to temperature. • Improved Load deformation response of insulated test specimen exposed to high temperature. • Improved structural response of CFRP strengthened concrete cylinders wrapped with insulation. • Effect of insulation thickness on thermo-mechanical performance of concrete. Abstract The present work looks at the effectiveness of thermal insulation of concrete and repair material – CFRP wrapped around concrete cylinders, using geopolymer mortar and simwool ceramic fibre blanket. The thermal insulation tends to prevent delamination of CFRP when exposed to high temperature (400 °C–715 °C). It is observed from the results there is an improved load deformational response of concrete and CFRP wrapped cylinders due to insulation being applied using geopolymer and fibre blanket when exposed to high temperature is significant. Parametric studies were carried out using FE analysis to validate the experimental results and to study the effectiveness of insulation, for different insulation thickness of geopolymer and cermic fibre blanket. [ABSTRACT FROM AUTHOR]

Three different types of plastic waste replacing up to 50% of natural aggregates are used in concrete mix design. A wide set of basic physical, mechanical, thermal, and hygric properties of developed concretes is determined and their assessment is made using a comparison with reference data. The mechanical parameters, though decreasing with the increasing amount of plastic aggregates, are found satisfactory for non-bearing concrete structures. The up to seven times lower thermal conductivity, as compared with the reference material, provides an evidence of greatly improved thermal insulating capabilities. The hygric properties of designed concretes are characterized by an increase of water and water vapor transport parameters and a decrease of water vapor adsorption capacity with the increasing amount of plastic aggregates. Based on the obtained experimental results, a conclusion can be made that the designed lightweight concretes containing plastic waste aggregates present a prospective solution from the points of view of both plastic waste disposal and improvement of buildings' energy efficiency. [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]

In this paper, mechanical and thermal properties of compressed earth blocks stabilized (soil–sand dune–cement) with and without aggregates of cork have been studied, with the use of some models that predict thermal conductivity for comparison of experimental results. The first part highlights the influence of the percentage by weight of cement and of sand dune on the maximum dry density, optimum moisture content and mechanical resistance. The results showed that mass content of 30% sand dune and 12% cement significantly improves these properties more in the wet conditions than dry, and therefore gives the optimal mixture (58% of soil–30% of sand dune –12% of cement). However, the composite materials used for building must present sufficient mechanical strength to be suitable for constructions. For that the optimal composition has undergone a static compaction (2.5–5–7.5–10 MPa) thus showing further improvement on the same properties. Incorporating the aggregates of cork (3/8) in the optimal mixture, improves significantly the thermal performance with little influence of compaction, while remaining within the range of acceptable strength. Lastly the study was extended to the search for theory capable of predicting the effective thermal conductivity of a dry blend considered like a two-phase system, which shows that linear model and some theoretical models give the best concordance with experimental results. [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]

Abstract: Thermal properties of five screed specimens were evaluated by four different thermal analysis methods. Thermal conductivity results showed that samples with recycled glass aggregate had a substantially lower thermal conductivity compared with those of sand screeds. Variation of heat capacity between the glass and sand screed mixtures increased with elevated temperature to a significant extent; the glass screeds seemed to show the highest heat capacities at these increased levels. The 100% glass aggregate specimens exhibited a lower thermal expansion at higher temperatures showing a higher dimensional stability. From the results a model was created to assess some realistic scenarios which the screeds may be presented with. A comparison of the screeds over different temperature ranges was produced. Glass screeds were shown to save approximately three times the energy of conventional sand counterparts due to good thermal insulation. When compared, the 100% glass with rapid cementations provided the best possibility for financial savings. The study demonstrated that glass aggregate screeds could be used as a cost effective and environmentally friendly building material that superseded sand alternatives dramatically in thermal retention. [Copyright &y& Elsevier]

[Display omitted] • Thermal conductivity of RHA-based mortar is lower than the conventional mortar. • Addition of RHA in mortar reduces the heat transfer through the wall by 26%. • RHA substitution of 30% in the wall plaster reduces the heat flux by 10%. • RHA-based mortar decreases the greenhouse gas emissions by about 14%. The energy used to maintain the thermal comfort of buildings significantly contributes to the GHG emissions and global warming. In this study, a sustainable and cost-effective rice husk ash (RHA)-based mortar for wall plastering has been developed to provide better thermal insulation, reduce the operational energy and enhance the thermal comfort. Consequently, RHA was partially replaced with the sand in the conventional mortar to produce the RHA-based plaster. Initially, compressive strengths and thermal conductivities of the selected mortar mixes were assessed. The results highlight that the RHA can be replaced up to 30% instead of sand in mortar to produce the thermally enhanced wall plaster. Further, two identical prototype model houses were constructed with RHA-based (i.e. 30% of RHA) and conventional plasters to evaluate their heat transfer, heat flux, and the characteristics of internal and external wall surface temperatures in open weather conditions. It was noted that the average peak heat flux reduction formed by the RHA-based plaster was 10%. The average daily heat transfer reduction across the wall with RHA-based plaster was about 26%. Results also show that RHA-based plaster can reduce the energy that required to maintain thermal comfort by about 9% than the conventional plaster. Moreover, the environmental impact analysis was also conducted to assess the sustainability performance of RHA-based mortars. The environmental impact assessment revealed that the RHA-based plaster has less environmental impact than the conventional mortar. Furthermore, the CO 2 emission generated by the production of RHA-based mortar is about 14% less than the conventional plaster. [ABSTRACT FROM AUTHOR]

• Assessment of water resistance, mould susceptibility and surface properties of ETICS. • Moisture content influence on the thermal conductivity of the insulation layer. • Definition of ETICS performance parameters. • Contribution towards the development of ETICS with improved durability. The use of External Thermal Insulation Composite Systems (ETICS) significantly increased in the last decades due to their enhanced thermal properties, low installation cost and ease of application, not only in new constructions but also for thermal retrofitting of building facades. These multilayer rendering systems are constantly exposed to weathering agents and anthropic factors which can lead to physical-mechanical and aesthetical anomalies and thus affect their durability. However, possible synergetic effects among these agents are often neglected by international technical documents on the evaluation of the effectiveness and durability of ETICS. With the aim of filling this gap, moisture transport properties (capillary water absorption, water vapor permeability, water absorption under low pressure, and drying kinetics), thermal conductivity, mould susceptibility and surface properties (color, gloss, and roughness) of twelve commercially available ETICS were assessed and discussed. Possible links between these factors were analyzed and ETICS performance parameters were defined. Results demonstrate that a deeper knowledge of the correlation among ETICS properties can effectively contribute to the evaluation of the efficiency and long-term durability of these systems. [ABSTRACT FROM AUTHOR]

• Buildings consume a lot of energy and there is a need to improve their thermal properties. • The use of cork in cement composite reduces the density and decreases thermal conductivity. • Air curing and cement substitution with slag also reduce the thermal conductivity. • The shrinkage increases with the increase in the cork content. • The strength of cork cement composite is reduced but is adequate for heat insulation and non-load carrying elements. Construction industry consumes a lot of energy either through the materials used or by heating and cooling. Insulation materials using waste materials could help reduce the energy consumption. Waste cork is abundant in Mediterranean countries and is rarely used as a construction material. Cork presents excellent thermal and acoustic performance and could be used in heat insulation for roof elements. This paper aims to investigate the mechanical and thermal properties of cement composites with waste cork under different curing conditions. The effect of including granulated blast furnace slag on these composites was also studied. The results indicate that the strength of cork cement composite is adequate and meets the standards requirements for heat insulation elements. [ABSTRACT FROM AUTHOR]

• Water treatment sludge (WTS) is incorporated to expanded clay for LWA production. • The expanding properties of LWA are slightly reduced with WTS addition. • LWAC formulated with commercial LWA is similar to LWAC with LWA containing WTS. • WTS can be revalorised by LWA production. Water treatment sludge is an industrial by-product which has recently been classified as a waste by the European Commission. The main goal of this work is to valorise this waste to produce lightweight aggregates. Formulations with sludge substituting expanded clay up to 50 wt% were produced. The physical properties of the lightweight aggregates such as bloating index, density and porosity were studied. The introduction of the sludge without expanding properties, reduced the expandability of the clay and the porosity of the aggregates. The density increased from 0.32 g/cm3 in aggregates without sludge to 1.46 g/cm3 in aggregates with 50 wt% of sludge. It is shown that lightweight aggregates can be produced using mixtures of expanded clay and water treatment sludge, with low substitution percentages (up to 15 wt% of sludge). Aggregates up to 15 wt% of sludge were further studied. The compressive strength increased with sludge wt.%, and the concentrations of heavy metals and metalloids, assessed through leaching tests, were well below the stablished limits. Two preliminary tests of lightweight aggregate concrete were produced: LWAC 1 was formulated with commercial lightweight aggregates and LWAC 2 with aggregates containing 7 wt% of the sludge and commercial lightweight aggregates. The physical, mechanical and thermal properties of LWAC 1 and LWAC 2 were found to be very similar. Our work demonstrates the feasibility in using water treatment sludge as a by-product to produce lightweight aggregates suitable for thermal insulation and lightweight applications. [ABSTRACT FROM AUTHOR]

• Reuse of feldspar in construction materials. • Functional properties are highly improved with the replacement of sand by feldspar. • Heat-islands in cities could be reduce using these materials. The use of white cements as a building material is widely employed due to its high whiteness and reflectance. However, building materials should adopt better thermal insulation characteristics to contribute for a significant urban heat-islands mitigation. In this work, synthetic feldspar has been evaluated as partial and total replacement of sand in white cement mortars. Thermal, mechanical, and optical properties of these new mortars are characterized by thermal conductivity, compression resistance test and reflectance-colorimetry, respectively. The replacement of sand by synthetic feldspar allows to obtain white mortars having ≈18% improvement in solar reflectance. Experiment under solar irradiance of mortars having synthetic feldspars reduce the surface heating of the mortar in 25% and the heating transmission to the rear of the mortar in >55%. Moreover, the high crystallinity of the synthetic feldspar reduces the mortar expansion due alkali-silica reactions (ASR). Improvement in reflectance and thermal conductivity resistance of white cement mortar having synthetic feldspar opens a wide range of building material applications. [ABSTRACT FROM AUTHOR]

• Optimized compositions of mastic were recommended in the cool pavement. • Heat flux was transferred in a different way in the cenospheres and the graphite. • Bruggeman's model can be used to describe the thermal properties of mastic. • Spherical cenospheres contributed less to rutting resistance of mastic. The cool pavement with the function of oriented heat conduction was designed to improve its deformation resistance and decrease the heat island effect. Lots of research had been performed on the thermal properties of asphalt mixture in the cool pavement, but less of them focused on the mastic which played a vital role in the heat conduction. In this study, the normal filler, the cenospheres and the graphite were adopted to prepare the mastic samples. The normal filler was made of the limestone, and the cenospheres were obtained during coal-burning process in coal-fired power plants. The thermal conductivity analyzer was used to investigate the thermal properties of mastic. The scanning electron microscopy was employed to observe the morphological characteristics of different fillers. Dynamic shear rheometer was adopted to evaluate the rheological properties of the mastic as a function of temperature. Bruggeman's model and the finite element method were used to analyze the mechanism of thermal transmission of mastic. Based on the results, the mastic with the ratio of binder:normal filler:cenospheres = 1:0.5:0.5 by weight was recommended to be applied on the top layer of the cool pavement to improve its thermal insulation, and the one with the ratio of binder:graphite = 1:1 was recommended in its sub-layer to improve its thermal transmission and rutting resistance. [ABSTRACT FROM AUTHOR]

• Infrared thermal imaging can effectively detect corrosion of rebar in concrete. • Corrosion of uncoated rebar increased thermal insulation of the reinforcement. • Corrosion of epoxy coated rebar decreased thermal insulation of the reinforcement. • Cracks in the epoxy coating decreased thermal insulation of the reinforcement. Infrared thermal imaging is a novel corrosion detection technique that is influenced by the thermal properties of the object under investigation. This study investigated the effect of corrosion of epoxy coated and uncoated rebar on the thermal behaviour of reinforced concrete without electromagnetic influences. A heating element was inserted into the rebar embedded in concrete. The heating element heated the rebar from the inside and the thermal response on the concrete surface was monitored with an infrared camera. The thermal measurements showed that corrosion thermally insulated uncoated rebar. However, corrosion of epoxy coated rebar led to cracking of the coating and thereby reduced the thermal insulation of the rebar. [ABSTRACT FROM AUTHOR]

• Microsilica increase mechanical properties without affect acoustic properties. • Higher microsilica percentage, impact in a porosity smaller. • With 5% of microsilica, better is the thermal conductivity. • It is possible to obtain a 87.85% of porosity with 0.20% of microsilica. Gypsum is an ancient material of great abundance that can be used as acoustic and thermal insulation protection in civil construction, especially when water-based foam is added to it, improving these properties. This research presents gypsum foam processing using a direct casting method with additives from natural sources, thus avoiding environment degradation. The results showed that gypsum foam has a potential for thermal and acoustic insulation and is more effective than other materials currently being used. Although, the material mechanical strength decreases when only water-based foam is added, further microsilica (MS) addition improved its mechanical strength without spalling its acoustic absorption and thermal conductivity. [ABSTRACT FROM AUTHOR]

• Effect of waste perlite and activation by jet mill on structure of cement paste is revealed. • Decrease in density and heat conductivity of plaster mortar is established. • Standard physical properties of plaster mortars are due to improved structure of cement paste. • The superplasticizer reduce the segregation of the cement-perlite mix. • Technology for production of low-density plaster thermal insulation mix was developed. The direction of many leading states is aimed at the development of the Arctic, so the creation of new generation thermal insulation materials is given priority. The novelty of the paper is to identify the scientific patterns of the influence of binder composites based on Portland cement and waste of expanded pearlite sand during joint jet grinding on the hydration mechanism and the structure of the plaster mortar. The grinding of heat-insulating binders in ball, vibration and vortex jet mills was studied. The features of hydrated phase formation and hardening of modified binders were studied taking into account the chemical, structural and morphological features of perlite wastes. Besides, the microstructural, morphological and thermal properties of the hardened binders at 28 days of curing were determined. For the first time, the scientific data were obtained on the properties of modified heat-insulating binder and plaster mortars based on it, obtained by mechanochemical jet activation. The results indicate that the jet activation of the modified binder based on Portland cement, waste from the production of expanded perlite sand and superplasticizer, contributes to the improvement of the physicomechanical properties of 28-days hardened binder: the compressive strength of 84.2 MPa and density of 2100 kg/m3. Based on the developed modified binder, the effective heat-insulating plaster mortars with heat conductivity of 0.051–0.059 W/(m·°C), a density of 240–260 kg/m3 and a compressive strength of 1.3–1.43 MPa were obtained, which meets the requirements. Technological route for the production of low-density plaster thermal insulation mix was developed. [ABSTRACT FROM AUTHOR]

• Mortars with 6% crumb rubber are non-combustible and do not propagate flames. • The increase of rubber content decreases the thermal conductivity of the mortar. • Rubber mortars cracking after thermal accelerated aging is lower than the reference. • Use of crumb rubber in rendering mortars maintains the adhesion to ceramic substrate. The difficulties related to waste tire disposal encourage the use of crumb rubber in civil construction as a component of cement composites. In this study, crumb rubber is evaluated as a partial replacement of the aggregate in rendering mortars, in quantities of 0%, 2%, 4% and 6%, using a systemic approach. A wide range of characteristics were analyzed, related to the fresh and hardened mortar, thermal and fire properties, along with the durability of the composites used as rendering mortar. Crumb rubber mortars require a higher water content to achieve the same workability of the control mixture, decrease the bulk density and increase the water retention and air content of the mortar. The flexural strength is maintained for hardened mortars with up to 4% crumb rubber, the compressive strength and dynamic modulus of elasticity are maintained only up to 2% rubber, with the decrease of these properties at higher contents of the residue. Generally, water absorption raises with the increment of rubber, but capillary water absorption decreases. The mortars do not propagate flame and they are non-combustible. The addition of crumb rubber leads to a reduction in thermal conductivity of up to 32% for the mortar with 6% of crumb rubber, which enhances their behaviour as a thermal insulator. The durability of rendering mortars with crumb rubber is increased, reducing cracking and maintaining their tensile bond strength at the same level of the reference mortar, even after thermal cycles of accelerated aging. The rendering mortars with 2% and 4% of crumb rubber content presented the best set of properties related to deformation capacity, thermal insulation and lower cracking, with tensile bond strength above the minimum required at standards. [ABSTRACT FROM AUTHOR]

• ACCs preparation without aggregate floating and aggregate size effect. • The compatibility improvement between aerogel slurry and cement matrix. • Optimization of matrix by using nanosilica and high-temperature curing system. • Correlation between pore structure and properties. • The realization of coordination between thermal insulation and mechanical properties. Lightweight aerogel/cement composites (ACCs) were prepared by introducing a silane coupling agent modified aerogel slurry into a nanosilica enhanced cement paste. The effect of the modification on the pore structure and hardened performance of ACCs was investigated. The results indicate that nanosilica can enhance the matrix. Surface modification of aerogel results in better compatibility and facilitates the preparation of ACCs with synergistic mechanical properties and thermal insulation properties. An ACC with a thermal conductivity of 0.067 W/(m·K), a compressive strength of 1.2 MPa and a density of 390 kg/m3 was successfully prepared by 66 vol% replacement of cement paste with the modified aerogel slurry. In addition, the total porosity and average pore diameter of the composite are 72.8% and 170.9 nm, respectively. [ABSTRACT FROM AUTHOR]

• The waste paper is transformed into Aggregates of Waste Paper (AWP). • New biocomposite based on the Aggregates of Waste Paper and Lime (AWPL) is formulated and characterized. • The microstructure of the new composite AWPL is characterized by high open porosity. • The thermal conductivity of the material AWPL are ranging between 0.097 and 0.012 W/mK. • The compressive strength of the material AWPL is ranging between 4.2 and 10.95 MPa. • The new material AWPL can be used as structural material and thermal insulation. In the aim of the valorisation of waste paper, an experimental study of a new biocomposite (AWPL) dedicated to building based on Aggregates of Waste Paper and Lime is performed. The waste paper used in this work is transformed to Aggregates of Waste Paper (AWP), the physical, thermal and morphological properties were carried out. Five combinations of (AWP – Lime) have been prepared and the weight ratios of lime used are 20, 30, 40, 50, and 60 wt% correspond. Experimental investigations of physical, mechanical, thermal and morphological characterizations of AWPL were carried out in order to determine: the apparent density, the open porosity, the water absorption, the ultrasound pulse velocity, the flexural and compressive strengths and the thermal conductivity. Furthermore, a characterization by Scanning Electron Microscopy (SEM) was realized to observe the AWP/lime bond. The results of characterization of AWPL show good mechanical properties as flexural and as compressive, these results are confirmed by the analysis SEM, that shown good adhesion of the AWP/Lime interface. The thermal characterization tests of AWPL have shown an important thermal insulation capacity linked to the low values of the thermal conductivity, these low values can be explained by the high porosity of AWPL. As a result, the AWPL could be classified as a structural and thermal insulation material for buildings according to the RILEM classification. [ABSTRACT FROM AUTHOR]

• Pore structure of the ETICS materials was analyzed by nuclear magnetic resonance. • The pore distribution of each layer was investigated through the NMR SE-SPI sequence. • Vapor adsorption mainly occurs in pores of size smaller than 0.1 μm. • The water absorption index D w was proposed to describe the water absorption capacity. In order to study the pore structure characteristics of the deteriorated structural layer of an external thermal insulation composite system (ETICS), the overall and stratified T 2 spectrum signals of the system made of thin-layer inorganic insulation mortar are tested by nuclear magnetic resonance (NMR) technique under different moisture transport conditions. The variation in moisture transport with pore size in the structural layer of the ETICS is studied under three conditions, namely, vacuum-saturation, free water absorption and vapor adsorption process, and indices are proposed to evaluate the vapor adsorption and free water absorption capacity of ETICS. The results indicate that the total pore volume is predominated by the pores in the insulation layer as revealed by the peaks of T 2 spectrum, which exhibit a bi-modal distribution with some larger pores. The pores in the finishing coat, protective layer and bonding layer have negligibly smaller size and smaller volume as revealed by a lower T 2 peak and an indistinct second peak. The moisture transport patterns of pores with different sizes are quite different. Vapor adsorption mainly occurs in pores of size smaller than 0.1 μm and free water absorption mainly occurs in pores of size smaller than 10 μm. [ABSTRACT FROM AUTHOR]