Effect of built-in mineral wool insulations durability on its thermal and mechanical performance

Thermal insulation and mechanical characteristics of cement mortar reinforced with mineral wool and rice straw fibers

Influence of EPS, mineral wool and plaster layers on sound and thermal insulation of a wall: a case study

The need for energy efficiency and sustainable building materials is increasing today. In this context, new material integrations that aim to improve the thermal and mechanical performance of building elements are being investigated. This study experimentally investigated the effects of two phase change materials (PCM-1(CACI 2 .6H 2 O), PCM-2(NEXTEK24D)) and a thermal insulation material (polyurethane) on the thermal conductivity and compressive strength of hollow bricks. The internal voids of the bricks were filled with polyurethane and two different PCMs to evaluate the contributions of these additives to the mechanical and thermal behavior of the building elements. The findings indicate that adding PCM increases the bricks’ thermal resistance values and reduces internal temperature fluctuations. Bricks filled with polyurethane and FDM showed increased compressive strength, up to 28 % vertically and 74 % horizontally, compared to reference specimens. This emonstrates that filling bricks with such materials improves their compressive strength and thermal insulation. In conclusion, bricks with PCM and polyurethane additives offer significant potential for energy-efficient building solutions, particularly in terms of thermal comfort and insulation. However, given the impact of these additions on mechanical performance, further research is needed to optimize material ratios and enhance applicability without compromising structural safety.

The escalating demands for energy efficiency and acoustic comfort in building, transportation, and industrial sectors have propelled intensive research and development in advanced insulation materials. This review provides a comprehensive overview of the fundamental mechanisms, material types, recent advancements, and multifunctional applications of both acoustic and thermal insulation materials. While often treated separately, the interplay and occasional conflicts between acoustic and thermal properties are crucial for developing integrated solutions. We begin by elucidating the fundamental physics of heat transfer (conduction, convection, radiation) and sound propagation (absorption, insulation, damping) to establish a clear mechanistic foundation. The article then systematically categorizes and analyzes traditional and emerging materials, including fibrous materials (mineral wool, bio-fibers), cellular materials (polyurethane, polystyrene, aerogels), and resonant structures, with a dedicated discussion on acoustic and thermal metamaterials. A significant focus is placed on sustainable and bio-based materials, nanomaterial-enhanced composites (e.g., aerogels, vacuum insulation panels), and smart/adaptive materials. The performance of these materials is critically evaluated based on key metrics such as thermal conductivity (λ), Sound Transmission Class (STC), and Noise Reduction Coefficient (NRC). Furthermore, the review explores the synergistic design of multifunctional materials and systems that provide concurrent thermal and acoustic insulation, a key frontier in material science. A dedicated section on performance optimization and modeling discusses how computational tools, including multi-scale modeling and machine learning, are accelerating material discovery. Finally, we discuss current challenges, such as balancing performance with sustainability, cost, fire resistance, and durability, and offer perspectives on future research directions, including the role of AI-driven material design, circular economy principles, and advanced manufacturing.

The use of thermal insulated decorative panel materials with low thermal conductivity and high flame retardance is a key step toward energy-saving buildings. However, traditional thermal insulation materials are always highly conductive and inflammable, which restricts their application for new buildings. This study aims to prepare the non-combustible, cement-based EPS mixtures with thermal conductivity lower than 0.045 and density less than 140 kg/m3 and characterize it with mechanical, thermal, and flame retardant properties. The effect of particle size, Silica coated and content of EPS on the physical, mechanical, thermal, and combustion performance are conducted in this paper. The comprehensive indoor tests including density, water absorbing, softening coefficient, compressive strength, tensile strength, moisture susceptibility, thermal conductivity, and scanning electron microscopy (SEM) along with combustion performance are reported to evaluate the effects of several variables on the investigated cement-based nonflammable EPS (CEPS)mixtures. The results show that small and gradation EPS particles significantly improve the comprehensive performance of mixtures. In addition, Silica coated ESP significantly improve the flame retardance of mixtures while reduce the mechanical characteristics slightly. These results contribute to the selection of appropriate materials to enhance the thermal insulation, flame retardance and mechanical properties of CEPS.

The evolution of traditional buildings reflects the uninterrupted development and the assimilation of the most worked out structural and architectural solutions. The new requirements of the EU regulations (from 2020 all new buildings must meet the requirement of almost zero-energy level) as well as applicable laws in Lithuania (the Lithuanian building regulations STR), however, set strict requirements which are difficult to apply to the traditional architecture.. On the other hand, not all measures aimed at building energy efficiency are compatible with the concept of ecology (usually attributable to the traditional architecture). Due to the aforementioned confrontation, the purpose of this research is to use the comparative analysis method to examine some of the measures determining energy efficiency of a building and the rationality of these measures in the context of building's lifecycle (which consists of construction, operation and demolition stages). One of the tested measures in this issue is the improvement of thermal properties of external envelope's elements to meet the requirements of existing building regulations (according STR2.05.01: 2005). The research examines the ability of the improved thermal resistance of traditional buildings' external envelope in assessing the benefits during the operation stage. The rationality is determined by comparing the energy savings during fifty-year-long lifespan (STR2.01.09: 2005) with the energy needed to produce the material (i.e. embodied energy). After comparing several different thermal insulation materials, e.g. mineral wool, EPS panels, straw insulation, the best solution is found. Besides the aforementioned, this research examines some principles of "passive design" applied in traditional buildings of various Lithuanian ethnographic regions. Four buildings varying in size, plan configuration, external envelope area, etc. were analyzed: "Viengale Pirkia" and "Dvigale Pirkia" from Dzūkija, "Troba" and "Kryžiavinis" houses from Žemaitija. The research is based on the methodology of evaluation of geometric efficiency by Parasonis, Keizikas et al . (2012a, b). The findings allow us to make the following conclusions: 1. The research has indicated that the energy savings of insulated buildings (per lifetime period) are several times bigger than the energy needed to produce the applied insulation materials. 2. Based on the ratio of embodied energy and saved energy of tested materials, the research shows that the straw is the most rational insulation. It is also characterized as being a natural material as well as eliminating the additional energy inputs for recycling. However, it requires larger structures capable to withstand higher loads. 3. The research of geometric parameters of traditional houses has shown that the usage envelopes of "Troba" and "Kryžiavinis" houses is most efficient: "Troba" because of the most compact volume and "Kryžiavinis" because of the largest hosted floor area. 4. The comparative indicators of buildings compactness show that energy is saved more effectively in the examples of traditional volumetric and plan solutions of buildings (usually with pitched roofs), when comparing them to modern houses with flat roofs. Therefore, seeking minimum usage of materials for construction and improving energy efficiency during operation period, the traditional pitched roof is the best solution.

Wood and mineral wool fractions from demolished buildings were sorted into different categories and processed to the suitable grain size needed for the manufacturing of wood-plastic composites. Processed construction and demolition waste materials mixed with plastics and additives were extruded into hollow test bars using a conical rotary extruder. Test specimens needed for measurements were cut from test bars. The results showed that the mechanical performance of wood-plastic composites based on construction and demolition waste wood, and mineral wool was at a good level and comparable to commonly used wood-plastic composites in decking applications. The highest strength properties of wood-plastic composites were achieved with a plywood fraction and the lowest with materials containing a particle/fibre board fraction. The mechanical performance can be improved by utilizing mineral wool in the formulation of wood-plastic composites. A material mixture containing several wood fractions as well as mineral wool also gave good strength properties. Only a minor reduction in strength properties was measured when recycled plastic was utilized meaning that wood-plastic composites suitable for many types of applications can be produced entirely from recycled materials.

Modern construction is not complete without complex, composite enclosing structures that consist of various elements and materials.
 The analysis of the energy efficiency of heat and vapor barrier materials in the USA and Kazakhstan is carried out, traditional materials such as mineral wool, expanded polystyrene, etc. are considered. The analysis of the possibility of using alternative materials to improve energy efficiency in Kazakhstan was also carried out. The properties and characteristics of steam-insulating materials are considered, the standards of the USA and Kazakhstan regulating the use of such materials in construction are presented.
 Considering several options of alternative steam-insulating materials for construction in Kazakhstan on the example of the city of Almaty, an analysis of its climate was carried out and based on the results obtained, the most suitable insulation materials for this region were determined.
 As the results, the advantages of using the selected materials were considered, and data on the characteristics of alternative steam-insulating materials were presented, where it can be noted that these materials can significantly increase the energy efficiency of buildings and reduce heating and cooling costs. Environmental aspects of the use of these materials were also considered.
 The use of alternative steam-insulating materials is an effective and more environmentally friendly option for improving the energy efficiency of buildings in Kazakhstan. These data may be of interest to specialists working in the field of energy efficiency of buildings and construction, as well as for manufacturing plants that are engaged in the production and sale of steam-insulating materials.
 Keywords: thermal insulation, standards, energy efficiency of thermal insulation materials.

Integrated insulation clay hollow blocks is an interesting constructive system in the context of Near Zero Energy Buildings and building energy efficiency. Their simple modification into supply air wall can increase their thermal performance without great effort. This paper deals with the creation of an original supply air wall or window test bench and with the numerical and experimental study of a supply air wall (or ventilated wall) based on modified modern integrated insulation clay hollow blocks where large cavities (about 4 cm) are filled by mineral wool. In some cavities, mineral wool is removed to create a flow pattern, which aims to recover heat losses from inside and solar energy from outside. At first, a 3D CFD numerical model is presented to assess the energy performance of a 1 m2 sample of ventilated wall. Then, an experimental test bench, based on a modified guarded hot box simulating solar effects and airflows between the two chambers, is carried out to assess the real performances. A comparison between these two studies allows validating the results which show a good correlation in terms of temperature difference gains between outdoor temperature and pre-heated temperature going up to a maximum of 14 K for only 1 m2 of wall and for a volume flow rate of 4 m3/h (4,5 K for 32 m3/h).

The thermal insulation performance of thermal insulation materials for cold storage has a great influence on the energy saving of cold storage, so many scholars have done a lot of research on it. This paper summarizes the production, application, and performance analysis of Polyurethane foam plastics (PU), Expanded polystyrene (EPS), Extruded polystyrene (XPS), and rock wool for cold storage, and summarizes the thermal insulation application of civil-type cold storage, steel structure cold storage, prefabricated cold storage and cold storage pipeline, as well as the cold storage anti-cold bridge measures.

In order to save energy consumption for air-conditioning of buildings throughout those lifecycle, thermal performance of insulation materials applied in buildings should be kept in required value. On the other hand, there are many factors of ageing of insulation materials such as ambient temperature, vibration and moisture etc. In the previous paper, main factors of thermal performance change were discussed and several experimental results were shown. This paper examines the influences of moisture on thermal performance of various insulations based on three kinds of experiment. In first experiment, the relationship between equilibrium moisture content and thermal conductivity of fiber insulations is obtained. Second experiment is on the influence of gaseous moisture on fiber insulations and the results show that the dimension change of fiber insulations is small even in very humid condition. Third experiment is on the reversibility of thermal conductivity after the internal dew condensation process and the dry process, and the results show that many insulation materials have reversibility except for several plastic insulation foams.

Abstract. The building and construction sector is among the most significant contributors to global warming. Indeed, modern construction materials have a major impact on the environment, from their extraction to their installation. Therefore, there is a need to develop new materials that are more durable and better suited to contemporary challenges. In this context, earth materials appear as a sustainable, economical, and environmentally friendly alternative. However, their mechanical strength is relatively low, and their sensitivity to water hinders their development. Thus, the main objective of this study is to assess the effect of using mineral additives, particularly natural pozzolan, as well as the influence of varying the type of binder on the mechanical and hydrothermal performance of earth blocks. In this study, two types of binders were used, namely plaster and cement, at a proportion of 10% by weight relative to the dry mix. In addition, four pozzolan contents (5%, 10%, 15%, and 20%) were incorporated based on the binder weight. After detailing the steps for preparing the samples to be tested in the laboratory according to the selected formulations and percentages, a physico-chemical characterization of the soil used in this study was carried out in order to classify it. This characterization includes the particle size analysis by sieving and sedimentation, plasticity assessment using Atterberg limits, evaluation of the clay fraction via the methylene blue test, and estimation of organic matter content through a calcination test. The research then focused on analyzing the mechanical, thermal, and hydraulic performance of the stabilized earth blocks. To this end, the samples were tested for uniaxial compressive strength and three-point bending to assess their mechanical behavior, thermal conductivity using the steady-state asymmetric hot plane method, and durability through total water absorption testing. Experimental results indicate that blocks treated with plaster exhibit better mechanical performance compared to those treated with cement. Moreover, plaster-stabilized blocks showed lower total water absorption than cement- stabilized blocks throughout the entire immersion period, regardless of pozzolan content. However, plaster is less resistant to water-related degradation: after 96 hours of immersion, cracks and disintegration of the material were observed. The study also showed that compressive strength increases slightly with the addition of pozzolan, up to a certain limit. Beyond 10% pozzolan content, strength decreases. In contrast, flexural strength decreases as pozzolan content increases. On the other hand, the incorporation of pozzolan leads to a reduction in thermal conductivity, and consequently, an improvement in thermal performance, due to increased porosity in the clay matrix

The applications of both open and closed cell cellular plastics for use as thermal insulation to improve energy efficiency in buildings and industrial processes are discussed. Brief details of the types and forms of cellular plastics available for such uses are included as well as typical data on thermal and other relevant performance properties and characteristics. Materials include extruded and expanded polystyrene, polyisocyanurate, polyurethane, and phenolic‐based materials. A variety of lesser used specialty materials include polyethylene, polyimide, and melamine. Temperature‐dependent properties discussed are thermal performance including aging phenomena and its required accelerated aging testing procedures, mechanical and structural performance. Flame resistance and other fire‐related issues are included as are health and safety issues. Thermal insulation is the second largest application of cellular polymers and the largest application of rigid foams. Refrigeration and residential and industrial construction are the biggest consumers of thermal insulation materials.

The design of thermal insulation in roofs is very important to reduce energy consumption and decrease the environmental impacts of buildings. An integrated economic and environmental assessment-based optimization design method is presented in this paper to find the best candidate insulation design scheme for building roofs, including the determination of roof thermal insulation type and the optimum insulation thickness. In the optimization design method, a zonal method-based double-skin ventilation roof heat transfer model is developed to predict the roof energy consumption. Economic and environmental benefits due to thermal insulation are calculated by using the economic analysis model, the environmental analysis model, and roof energy consumption. Moreover, an integrated dimensionless economic and environmental assessment index is proposed to evaluate different roof thermal insulation design schemes. The optimum insulation thickness is determined by maximizing the sum of economic benefit and environmental benefit due to thermal insulation. The validation results in a real building show that the predicted data for the zonal-based double-skin ventilation roof heat transfer model agreed well with the measured data, with a maximum relative error of 8.2%. The optimum insulation thickness of extruded polystyrene (EPS), mineral wool (MW), and polyurethane (PU) was between 0.082 m and 0.171 m for the single-skin roof in a low-temperature granary in Changsha region in China. The ranking of the integrated assessment indexes of thermal insulation is EPS > MW > PU. A double-skin ventilation roof can reduce the optimum thickness of thermal insulation. The best result is obtained by EPS for the double-skin roof with a grey outer surface color for the low-temperature granary roof in Changsha region in China. The influencing factors of insulation type, roof structure, and roof outer-surface color should be considered in finding the best candidate insulation design solution for building roofs. The integrated economic and environmental assessment-based optimization design method can help designers to efficiently find the best design scheme of thermal insulation to maximize the sum of economic benefit and environmental benefit for building roofs.

7 - Fire behavior of sandwich panels with different cores