Building Insulation Research Articles

REDUCING THE INFLUENCE OF THERMAL BRIDGES IN THE BASEMENT SLAB OF CAST-IN-SITU FRAME BUILDINGS IN EXTREMELY COLD REGIONS

Introduction. Heat insulation of multi-story buildings with a reinforced concrete frame on pile foundations under climatic conditions with extremely low outdoor air temperatures is complicated by high air infiltration. When such buildings are used in winter, the most characteristic are temperature regime violations on the first floor. Purpose of the study: The study aimed to evaluate various methods to reduce the influence of thermal bridges in the basement floor of a cast-in-situ frame building with pile foundations under extreme climatic conditions. Methods: Thermal performance of 3D models of enclosing structures was determined using the certified HEAT3 program. Options of internal and external heat insulation of the basement floor with thermal breaks in the structures were considered. Results: As a result of numerical analysis of standard basement floor designs, it was established that low temperature on the inner surface and significant heat losses are associated with the presence of through thermal bridges: reinforced concrete raft — basement slab — column — concrete block masonry. The most effective solution for heat insulation of cast-in-situ frame buildings is external heat insulation of the basement floor with a thermal break in the raft. Compared to the standard solution, heat losses through the corner section of the slab with the offset column are reduced by 33.6 %, and the minimum temperature on the inner surface is higher than the dew point.

Feasibility study of utilizing Autoclaved Aerated Concrete (AAC) waste for the production of cold bonded lightweight artificial aggregate using high volume fly ash (HVFA) binders

Autoclaved Aerated Concrete (AAC) is a popular construction material used for partitions and insulation in buildings. At the end of its service life, AAC (Autoclaved Aerated Concrete) will be demolished and subsequently disposed of in landfills, thereby creating depository problem. Therefore, the study of reutilization and recycling of AAC waste is imperative. Artificial aggregate production can be an alternative to the reutilization of AAC waste. This paper assesses the feasibility of using Autoclaved Aerated Concrete Powder (AACP) waste as a raw material for the production of artificial aggregate and investigate its physico-mechanical properties. The investigation incorporates the comparison of cement-based binder with high-volume fly ash (HVFA) binder with different replacement levels of cement. The study uses image analysis based on photographic, optical microscopic, and scanning electron microscopy (SEM) images, to describe the porosity of the aggregate. The results show that the AACP aggregates with both cement and HVFA binders meets the current industry requirement for density and cylinder crushing strength as lightweight artificial aggregate. The appropriate binder content lies between 30 % and 40 %. The best cement to fly ash ratio in HVFA binder is determined to be of 1:1 with 50 % replacement of cement with fly ash. Image analysis showed that the porosity largely affected the properties of the AACP aggregate such as density and water absorption. However, further investigation into the reducing high-water absorption of AACP aggregates is necessary to improve their overall quality.

Persistent heat islands monitoring of Tehran metropolis using temporal analysis of Landsat-8 satellite images.

The management and design of urban areas in metropolises pose significant challenges. Balancing diverse land uses within a metropolitan structure and addressing spatial and environmental constraints are just some of these challenges. Urban heat islands, which stem from factors such as inappropriate construction materials, inadequate building insulation, improper land use locations, and unsuitable built-up density, reflect environmental imbalances within urban infrastructure. Effectively addressing these temperature discrepancies can lead to energy preservation, reduced environmental hazards, and enhanced comfort for urban residents. This study employed Landsat-8 satellite images to identify and monitor positive and convex temperature disparities across various districts of Tehran over 3years (2018 to 2020) using three different strategies. These disparities are estimated through the differences in land surface temperature from the thermal trend of each district and their persistence has been assessed in seasonal, semi-annual, and annual strategies. The study found that industrial areas, including warehouses, were the significant contributors to the persistent presence of urban heat islands in summer and winter. Open areas with impervious surfaces or bare soil, particularly those lacking sufficient green cover, also significantly contributed to the heat island effect. Certain large shopping centers, often due to their air conditioning systems, were also consistently identified as persistent heat islands. Evaluations demonstrated that over 78.8% of the identified persistent heat islands were meaningful, with most located in the northern and western parts of Tehran.

Development of eco-friendly flame-retardant polyurethane using sustainable additives

Polyurethane (PU) stands as a pivotal polymer extensively employed in architecture, particularly for insulation in residential and industrial buildings, but the inherent flammability of PU poses a significant drawback, leading to the generation of hazardous fumes and gases; this demerit limits PU applications in various fields. Therefore, the development of environmentally friendly flame-retardant PU is of great significance practically. In this research, some attempts have been made to synthesize PU modified with three different flame-retardants separately: Lipids (soybean, oil, jojoba), Eggshells (CaCO3), and Lignin phosphate prepared from rice straw as sourced sustainably. The results of the Limit Oxygen Index (LOI) test for the raw sample without the addition of inhibitors showed 18.5%, while the sample with flame retardants was 23.5%, it has better thermal stability and the UL-94 grade advanced to “V0″. This study showed excellent promise as green additives for enhancing the mechanical, thermal and flame retardancy performance of these polymers.

Innovative silica aerogel fiberglass walls and roofs: A path to lower carbon emissions and higher energy savings

ABSTRACT Buildings account for a significant portion of global energy use and consumption. Buildings have substantial energy consumption due to the use of heating, ventilation, and cooling systems. It is evident that the insulation materials used in the design of building envelopes can efficiently reduce the cost of air conditioning by reducing external heat gains and losses. Additionally, the use of environmentally friendly and cost-effective can be beneficial from an environmental standpoint. This paper aims to evaluate the potential for cost savings in the air conditioning of buildings incorporated with silica aerogel fiberglass insulation in hollow concrete bricks (wall) and hollow roof tile (roof). Silica aerogel fiberglass insulation is extensively used for heat insulation purposes, including building insulations, due to its superior thermal insulation and flame retardant properties. The thermo-physical properties of silica fiberglass insulation and building materials were determined experimentally as per ASTM D 5334 standards. Twenty distinct building design concepts are investigated in this study, each featuring insulation-integrated concrete blocks composed of silica aerogel fiberglass: (WEM1) insulation layer in the outer side, (WEM2) insulation layer in the center, (WEM3) insulation layer in the inner side, (WEM4) insulation layers in the outer-middle, (WEM5) insulation layers in the middle-inner, and (WEM6) insulation layers in the outer-inner sides. Additionally, two arrangements of insulation-stuffed roof tiles, REM1 above the RCC and REM2 below the RCC. In addition, novel building designs integrated with insulation were analyzed numerically, related to environmental conditions that refer to two different scenarios in India (hot dry and composite climates). Thermo-economic analysis of novel wall and roof designs with silica fiberglass insulation materials on air-conditioning costs, carbon dioxide emissions, and payback time are compared with conventional roof and wall patterns. The thermo-economic analysis was carried out based on the number of degree-hours of heating and cooling to determine the building’s annual energy usage. The building model arrangement (WEM6-REM1), which consists of an insulation composite wall (WEM6) and insulation roof tile (REM1), demonstrated the greatest annual air conditioning cost savings of 3.4 $/m2/year and 1.74 $/m2/year when compared to conventional building design for climatic conditions of Kurnool and Gauhati. The building model arrangement (WEM6-REM1) composed of silica fiberglass aerogel insulation exhibits the highest reduction in carbon emissions of 65 kg/kWh and 33 kg/kWh, when compared to conventional building design analyzed in both hot-arid; (Kurnool) and composite (Gauhati) climatic conditions. The placement of insulation in the roof alone (REM1) has the shortest payback duration of 2.15 years. The results of this study point to a viable approach to enhancing building design decision-making and narrowing the performance gap in sustainable and energy-efficient strategies.

Flame retardant, hexabromocyclododecane, increases production of pro-inflammatory cytokines, interleukin 1-beta and interleukin 6, in human immune cells.

Hexabromocyclododecane (HBCD) is an environmental contaminant due to its use as a flame retardant in a variety of applications ranging from building insulation, furniture upholstery, and housing for appliances and electronics. HBCD is found in wildlife, human breastmilk, and serum. Interleukin 1-beta (IL-1β) and interleukin 6 (IL-6) are pro-inflammatory cytokines, whose dysregulation is associated with chronic inflammation and the pathologies that result, such as tumor growth, rheumatoid arthritis, Crohn's disease, and multiple sclerosis. HBCD has been shown to increase the secretion of both IL-1β and IL-6 from human immune cells. However, it is not clear if these increases are due solely to HBCD effects on the secretory process or whether it is stimulating cellular production of IL-1β and IL-6. This study examines if HBCD can increase the production of IL-1β and IL-6 by immune cells by simultaneously assessing secreted levels and cellular levels of these cytokines. Additionally, the mechanisms for any observed changes in production are investigated. Peripheral blood mononuclear cells were exposed to HBCD over a range of concentrations and lengths of exposure. HBCD was found to stimulate IL-1β and IL-6 production after 6hrs. of exposure and production was sustained and intensified at 24 hrs. This increase in IL-1β and IL-6 production appears to, in part, be a result of increased mRNA expression. Additionally, the MAPK pathways, specifically the p38 and p44/42 pathways, appear to be required for HBCD-induced increases in IL-1β and IL-6 production.

BN fiber aerogels with high solar reflectivity and thermal insulation for green buildings

There exists more than one-third of the stock of buildings that do not meet energy-saving building standards, so there is an urgent need for breakthroughs in the field of green buildings. Herein, we successfully prepared boron nitride (BN) fiber aerogels by sol-gel, freeze-drying and high-temperature pyrolysis. When the molar ratio of C3N6H6 to H3BO3 was 1:2 and the roasting temperature was 1000 °C, the BN fiber aerogel was produced with high specific surface area (257.690 m2/g) and high porosity (99 %). BN fiber aerogels, with their low thermal conductivity (0.043 W/(m·K)) and stable mechanical properties (no change after 45 cycles at 30 % strain), offered possibilities for thermal insulation in green buildings. Its hydrophobic properties protect the wall from the natural environment. In particular, it had a solar reflectivity of 98.6 %, which exceeds most reflective coating materials, enabling the cooling of green construction on hot summer days. The high-temperature resistance of BN fiber aerogels could be applied in special environments such as blast furnace plants and thermoelectric power plants.

Tuning Rigid Polyurethane Foam with Eco-friendly Cellulose Nanocrystals from Oil Palm Empty Fruit Bunches as Energy-Efficient Material Composites for Buildings

The development of novel materials based on renewable materials with beneficial properties that assist with energy efficiency and conservation has been encouraged by increasing consciousness of environmental issues. This research intends to use sustainable cellulose nanocrystals (CNC) obtained from oil palm empty fruit bunches (OPEFB) as reinforcement to enhance the properties of rigid polyurethane foam (RPUF). RPUF reinforcement with varied CNC concentrations (0.25–1 wt%) was examined by foaming behavior, surface morphology, mechanical properties, thermal insulation properties, dimensional stability, efficiency energy study, and CO2 reduction through their thermal conductivity values. The results achieved an optimal improvement of mechanical properties of the RPUF composite by around 23.53% compared to RPUF control, at the addition of 0.5 wt% of CNC concentration while maintaining the density of 37–39 kg/m3. Further, incorporating CNC improved thermal insulating performance by 9.95%, as reflected by decreased thermal conductivity from 0.0292 W/mK to 0.0269 W/mK and decreased cell size by 28.12%. Finally, based on the energy and cost efficiency studies, RPUF-CNC composites offer up to 0.78 kWh/m2 and 0.031 kWh/m2 compared to conventional wall materials made of concrete and wood, respectively. Furthermore, it contributed to reduced greenhouse gas (GHG) emissions by 110 and 7.2 kg CO2/year compared to concrete and wood, respectively. This work demonstrates the promising use of eco-friendly building insulation materials to mitigate the energy and environmental crisis.

Engineering advanced cellulosics for enhanced triboelectric performance using biomanufactured proteins

Biological polymers, such as polysaccharides and polypeptides, offer renewable and biodegradable solutions for a more sustainable future. These polymers comprise natural building blocks, such as amino acids and glycans, which ensure their true environmental benefits at the end of their lifecycle. For example, cellulose is a highly sustainable material with many excellent properties, including renewability, biodegradability, and versatility in its functionality. It can be used in various forms, such as textiles, packaging materials, and building insulation. Here, we studied advanced cellulosic materials produced by blending or creating bi-composites with biomanufactured proteins inspired by squid ring teeth (SRT). Biomanufactured proteins can be synthesized in larger quantities, have a controlled production process, be modified to create desirable variants, and their production can be scaled up or down. Specifically, we engineered recombinant SRT proteins to have high electrostatic charge, induce crystallinity, and provide polar hydroxyl groups, which enhances cellulosic materials’ triboelectric response. The triboelectric voltage of blend triacetate and cellulose fibers increased by 72–108% and 49–57%, respectively, with a protein content of 10% wt. Furthermore, coating proteins on cellulosic fibers to create bi-composite fibers is a highly effective method for doubling (200%) the triboelectric performance. This finding has important implications for developing sustainable triboelectric materials and producing advanced materials using biomanufacturing.

Evaluation of thermal insulation capacity and mechanical performance of a novel low-carbon thermal insulating foam concrete

The use of building insulation materials is an effective measure to reduce building energy consumption. To improve the sustainability of insulation materials, desert sand (DS) was used to replace part of the binder, and rice husk ash (RHA) was incorporated to further improve the performance of foamed concrete. The fresh properties, strengths, thermal properties and thermal insulation function of DS-based foamed concrete (DSFC) were systematically investigated. The use of DS and RHA to replace part of Portland cement (PC) and fly ash reduces the flowability of the mixture when the water/binder (PC, fly ash, DS and RHA) ratio is constant. Although the incorporation of DS into foamed concrete increases its density and thermal conductivity, it improves the volume stability of the sample. The strength of specimen with DS decreases due to the low reactivity of DS, which also reduces the content of hydration products. Further incorporation of RHA not only improves the matrix strength by increasing the C-S-H content but also improves the pore structure of the DSFC by increasing the yield stress of the paste. The joint application of DS and RHA effectively reduces the heat storage coefficient and thermal inertia index of DSFC, which is beneficial to improve the thermal insulation capacity of buildings and reduce energy consumption. Incorporating DS and RHA can effectively improve the environmental and economic benefits of the foamed mixture, and the unit strength cost and carbon emission per cubic meter of the 5%–10% RHA-modified samples are reduced by 20.3%–39.1% and 20.2%–38.9%, respectively, compared with the DS35. This research provides a new approach and theoretical basis for building energy saving and external wall insulation.

Thermal, mechanical property and flame retardant analysis of bio-based rigid polyurethane foam modified with expandable graphite

As an energy-efficient building material, rigid polyurethane foam (RPUF) has attracted attention. However, there are still great challenges in how to easily prepare RPUF materials with good mechanical properties, flame retardant properties, thermal insulation and other properties. In the current work, expandable graphite (EG)-modified lignin-based polyol (RPUF) was prepared by a one-step method. Thermogravimetric analysis was used to study the pyrolysis of modified foams under nitrogen conditions. It was found that the RPUF-4 with an EG of 10 wt% had the highest the apparent activation energy (E), integral procedural decomposition temperature (IPDT), initial temperature and residue rate. And RPUF-4 also had excellent thermal insulation properties. In addition, RPUF-4 exhibited excellent flame retardancy and smoke suppression properties (peak heat release rate (RHRR), total heat release rate (THR) and Ds were 65.46 %, 23.92 % and 45.94 % lower than those of the unadded RPUF, respectively). At the same time, RPUF-4 also had good mechanical properties and energy absorption properties. These results will lay the foundation for the development and application of RPUF in the field of building insulation.

Optimization of microwave-produced coal-derived char insulation foam using response surface methodology

A new char-based insulation foam (CIF) is developed using coal-derived pyrolysis char (PC) and lignin, a paper and pulp industry byproduct. In this study, CIF is prepared by adopting the microwave method and Response Surface Methodology (RSM) is utilized to optimize predictions about the properties such as thermal conductivity, foam texture, compressive strength, and pore distribution of CIF. The three independent variables including percent char content, lignin/char ratio, and foaming agent/polyol ratio are considered in the RSM methodology. The face-centered central composite design is selected to obtain 17 test runs. Optimization of the predicted responses is performed to find the recipe considering a composite desirability function. Confirmatory test results show agreement between the predicted and observed values, with the percent error ranging from 0.00 % to 11.35 %, thereby confirming the accuracy of the prediction equations. The optimized CIF exhibits a thermal conductivity of 0.0633 W/m.K and a compressive strength of 695 kPa making it comparable to or better than traditional building insulation products such as fiber insulation, polymer composite, particle board, and ceramic glass foam. Therefore, this new CIF has the potential to be used as an energy-saving insulation material for building envelopes.

Lessening the energy usage of buildings: An exploration into green walls practicalitie

The article provides insights into green walls’ potential and energy-saving mechanisms in Melbourne, Australia. The use of vegetation on a building’s façade has been shown to positively affect the building’s demand for heating and cooling and a range of additional benefits. A mixed research study has been developed to explore and quantify using vegetated facades as a feasible option for reducing energy usage in commercial buildings. These results show that a green wall of building construction holds a similar level of thermal resistance as a 2.5cm layer of expanded polystyrene building insulation, at an R-value of 0.38m2 K/W. Combining this calculation with speculations as to the benefits of shade, evapotranspiration, and wind production has produced data showing a typical green wall can reduce the energy usage of a commercial building by up to 12%. This figure supports the use of vegetated façade systems to reduce energy usage in the built environment. This study can be instrumental in raising awareness for building and property professionals, as well as occupants, of the positive effects of green (vegetated) walls on the façades of buildings as a viable option for reducing heating and cooling loads and consequently, reducing spending on energy usage.

Change in the Properties of Expanded Polystyrene Exposed to Solar Radiation in Real Aging Conditions

Although polystyrene materials with added graphite are actively used for the thermal insulation of buildings, there are serious problems with the detachment and warping of these materials under the influence of solar radiation. However, no systematic studies have yet been carried out on the aging of polystyrene under exposure to solar radiation. The article presents research aimed at determining changes in the thermal conductivity, compressive stress, tensile strength, and water absorption of expanded polystyrene with the addition of graphite, exposed to direct solar radiation under in situ conditions. For this purpose, expanded polystyrene (EPS) with the addition of graphite (gray EPS) and expanded polystyrene made of composite panels (gray EPS and white EPS) were exposed to direct solar radiation under in situ conditions. A third sample (reference), which was entirely white polystyrene (without the addition of graphite), was included in the tests. The results showed that expanded polystyrene with the addition of graphite degraded under the influence of direct solar radiation but improved its strength properties. Expanded polystyrene made of composite improved its compressive strength properties by nearly 11 kPa (18%), and expanded polystyrene with the addition of graphite improved its compressive strength properties by 0.4 kPa (0.5%). And the tensile strength for composite-made expanded polystyrene increased by 7 kPa (9%), and that for expanded polystyrene with the addition of graphite increased by 26 kPa (37%). At the same time, water absorption for expanded polystyrene made of composite also increased by 0.06 kg/m2 (60%), and that for expanded polystyrene with the addition of graphite increased by 0.04 kg/m2 (44%).

New robust multi-criteria decision-making framework for thermal insulation of buildings under conflicting stakeholder interests

The choice of thermal insulation technology for existing building retrofit can be a complex multi-criteria decision-making (MCDM) problem characterized by multiple stakeholders with conflicting interests. The conflicting interests of the building owners and the policymakers could negatively influence the adoption of low-carbon energy retrofit measures by building possessors, slowing down the progress toward sustainable development. The investigation of this issue is, therefore, crucial to support more informed decisions and offer policymakers useful insights to develop future economic incentives for energy refurbishment of buildings. Most of the existing MCDM studies on the subject do not emphasize the differences among different stakeholders nor consider the outcomes' robustness. To overcome this gap, this paper integrates multi-stakeholder analyses and robustness assessments to provide broad-spectrum and reliable results. An innovative robust MCDM framework for building thermal insulation under conflicting stakeholder interests is proposed and tested on a real case study building (located in Southern Italy) using building dynamic energy simulation. Several alternatives of thermal insulation are evaluated under environmental, energy, and economic key performance indicators (KPIs). The Analytic Hierarchy Process is used to define criteria weights for conflicting decision-makers representing collectivity (policymakers) and private interests. TOPSIS, VIKOR, WASPAS, and MULTIMOORA methods are integrated to perform initial rankings of the alternatives. A rank similarity analysis is performed to evaluate the consensus between MCDM methods, and an ensemble ranking is obtained for each decision-maker using an approach based on the half-quadratic theory. A Confidence Index and a Trust Level are used to evaluate the agreement among the MCDM approaches, verifying the reliability of the final ensemble ranking. The robustness of the framework is attained by complying with well-established literature guidance. The hybrid MCDM analysis showed that porous materials like expanded clay and expanded perlite lead to better results under the KPIs investigated. The worst performances are attained by vacuum insulation panels and aerogel, mainly due to high values of embodied CO2 emissions and long payback periods. Insights upon the performance of different thermal insulating alternatives are also highlighted by the study and a stakeholder comparative analysis demonstrates that global rankings obtained for the different decision-makers show some similarities, but also important deviations, and a full compromise solution is not achieved.

Pre-treatment and its effect on the thermal conductivity of natural lignocellulosic rice straw stubble waste boards: Analysis vis a vis potential for the civil engineering applications

Once built, the residential or commercial building must maintain a temperature suitable for human comfort. Presently, according to an estimate, building energy consumption contributes about 40 % to global greenhouse gas (GHG) emissions. Thus, it is necessary to develop building materials that not only have low or zero carbon footprints during their production stage but also provide thermal insulation for buildings amidst variable climates. Among such materials, the use of straw waste boards can not only offer an opportunity to reduce the use of GHG-intensive materials but also provide excellent thermal insulation. The objective of the present work is to fabricate, characterize, and evaluate the thermal conductivity of composite boards made from rice (Oryza sativa) straw. The effect of water and alkali pre-treatment is also evaluated. Three different mass fractions (Mf) with 50 %, 60 %, and 70 % of straw by weight are considered, and three different matrix materials, viz., Polyethylene (PE), Polylactic acid (PLA), and epoxy resin, have been used. Among these, the epoxy matrix is found to be most suitable owing to its uniform dispersion, which leads to superior adhesion in the straw laminates. Subsequent morphological characterization techniques, such as energy dispersive spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD), have been employed to evaluate the physicochemical structure changes of straw fibre and fibre boards. The microstructural characterization revealed that the alkali and water pre-treatment have a pronounced effect on the morphological properties of straw and composite boards. Thermal conductivity has been measured using the experimental setup based on the guarded hot plate method, and the lowest conductivity of heat is recorded in the order of 0.023 W/mK. The present research work attempts to demonstrate the development of a novel product using rice straw waste that can potentially replace/reduce the usage of EPS (Expanded Polystyrene) for building construction applications in the near future.

Measuring effects of insulation renewal on heating energy and indoor thermal environment in urban residence of hot-summer/cold-winter region, China

Optimizing thermal insulation in residential buildings is crucial for energy efficiency, especially in Hot Summer and Cold Winter (HSCW) region. Current research often neglects retrofitting and real-life measurements, relying instead on simulations. This study conducted insulation retrofitting on a Chengdu high-rise residential unit, focusing on the flexible heating habits locally. The insulation renewal work involved transforming the thermal insulation structure by adding insulation to all internal surfaces of the rooms' opaque structure, including external walls, internal walls, ceilings, and floors. Experiments based on residents' routines quantified energy savings and improved indoor thermal conditions under intermittent heating. Results showed a significant decrease in daily heating energy consumption by 45.10 % on average, with a maximum of 55.53 %. The retrofitted room's energy-saving rate stabilized between 50 % and 55 % after the second hour. Indoor temperatures in the retrofitted bedroom increased by 0.7 °C on average and up to 1.4 °C. Raising the heating set temperature by 2 °C resulted in a 1.1 °C increase in the retrofitted room, higher than in the non-retrofitted one. These findings provide practical insights for renovating existing residences to achieve energy efficiency in the HSCW region.

Aluminium Hydroxide/Graphene-reinforced Rigid Polyurethane Foam Hybrid Composites

In this study, rigid polyurethane foams (RPUF) were successfully modified using 30 wt.% aluminium hydroxides (ATH), 1.0 pphp silicone surfactant, and different concentrations of graphene, using a one-shot one-step foaming method. This study aims to improve the compressive strength, flame retardancy, and thermal properties of RPUF by creating a synergistic effect between ATH and graphene in fire-retardant RPUF hybrid composites. The effects of a fixed amount of ATH and silicone surfactant and various loadings of graphene on RPUF were investigated. The results show that 0.5 wt.% graphene loading confers the best compression performance on the hybrid composite. Their compressive strength value of 12.58 KPa was higher than virgin RPUF (4.07 KPa) and RPUF/ATH (9.89 KPa). FTIR confirmed the functional groups in the virgin RPUF but could not identify new functional groups in most modified composites. The smallest amount of graphene addition (0.5 wt.%) produced a more stable hybrid composite structure. At 3.0 wt.% graphene addition, the maximum decomposition temperature of the RPUF/ATH hybrid composite was recorded (539oC), which was enhanced by 50% compared to virgin RPUF (296oC), and the highest char residue of 17.46% was observed. The incorporation of graphene enhanced the thermal firmness of the hybrid composite. The study also revealed an enhancement in the fire resistance of the hybrid composite. The LOI and UL-94 results showed that incorporating 3.0 wt.% enables increased LOI value and V-0 classification compared to virgin samples. This hybrid composite can be used in high-performance building insulation applications.

Analysing policy success and failure in Australia: Pink batts and set‐top boxes

AbstractThis article examines two Australian government programs from the Rudd/Gillard Labor government, the Home Insulation Program (HIP) and the Digital Switchover Household Assistance Scheme (HAS). Both became shibboleths of the Labor government's perceived waste and incompetence. Using key informant interviews and documents obtained under freedom of information (FOI), I analyse these programs against the multiple ‘dimensions’ of success proposed by Newman and common narrative frames around programme failure. I argue that the HAS was broadly successful across most dimensions of success, notwithstanding the adverse media attention. The study identifies four key factors driving HIP's failure: scheme design, installer training, demand control, and departmental expertise. All of these came back to the timeline pressures, driven by conflicting priorities, which in turn gave the Department of the Prime Minister and Cabinet (PM&C) more influence than would usually be the case. In comparison, HAS's success is attributed to crucial design choices, like the phased rollout and head contractor model. The article identifies the danger of ignoring subject matter expertise and poor policy/Cabinet processes, which have been reinforced by the recent Royal Commission into the Robodebt Scheme.Points for practitioners Demand‐driven programmes need to have demand‐side control techniques built into them. The role of central agencies needs to be carefully considered, particularly in relation to areas that are not their expertise, such as detailed programme development and implementation. Lessons about poor policy and Cabinet processes, as well as cultural change from the Pink Batts Royal Commission, do not appear to have been sufficiently embedded in the culture of the APS, as there are ongoing echoes of the same problems evident in the Robodebt Royal Commission.

Environmentally-Friendly Recycled Leather‑Reinforced Composite: Thermal and Acoustic Properties

Increase in energy consumption and environmental pollution are some of the main problems of today. One of the ways to overcome these problems is to increase the use of recycled materials. Heat and sound insulation in buildings can play an important role in saving energy and reducing environmental pollution with composite materials made from recycled leather. This study investigates the possibility of reusing leather scraps. Composite material was produced by cutting leather waste for thermal and sound insulation of buildings into small pieces and pressing them in a mechanical mold using polyvinyl acetate binder. The effect of the thickness of the developed new leather-added composite materials on their thermal and acoustic insulation properties was examined. When the thermal and acoustic properties of the composites were evaluated, it was determined that the PVA/skin thicknesses forming the mixture varied depending on the mean temperature and frequency (Hz). As a result of the measurements, it was seen that the sound at the 3000 Hz frequency, to which the human ear is most sensitive, was absorbed by 61%.