The aim of this paper is to propose ecological thermal insulation materials that meet the goals of sustainability but also fulfill the imposed thermal performance requirements. This paper studies new composite materials based on sheep wool from the perspective of thermal conductivity. The composites were prepared using two types of binder: acrylic-polyurethane resin and natural rubber latex, which were applied to the wool fibres through different methods and percentages. Based on the obtained results of thermal conductivity, two types of samples were selected for further analysis, which aimed to determine the microstructure, chemical composition, water absorption, attack of microorganisms, water vapour permeability, hygrothermal adsorption characteristics and sound absorption of the samples. In order to analyse the variation of thermal conductivity, the following parameters were taken into account: thickness, density, type of binder and percentage of binder. Following the obtained results, it was observed that the value of the thermal conductivity of the samples varies between 0.0324 and 0.0436 W/mK. It was found that all the samples prepared and analysed in this study fulfil the national criteria for the thermal performance of thermal insulation material. After conducting the in-depth analysis of the two selected sample types, it was concluded that both materials have good sound absorption characteristics over the considered frequency range. In addition, as it was expected from the natural fibres, the samples had low resistance against the attack of microorganisms and water-related tests.

The aim of this paper is to propose a novel sandwich panel, which would be suitable for sound absorption and airborne sound insulation, used as applied cladding or independent lightweight partition wall. As far as the authors are concerned, this is the first sheep wool-based sandwich panel using only natural materials. The structure was prepared using hydrated lime-based composite face sheets and a sheep wool-based core. Several parameters of the sandwich panel were determined, including sound absorption coefficient, airborne sound insulation, thermal conductivity, thermal resistance, compressive strength, and bending strength, respectively. The results indicate that the maximum sound absorption value of 0.903 was obtained at the frequency of 524 Hz in the case of the unperforated sample, 0.822 at 536 Hz in the case of the sample with 10% perforations, 0.780 at 3036 Hz in the case of the sample with 20% perforations, and 0.853 at 3200 Hz in the case of the sample with 30% perforations. The registered airborne sound insulation index of the panel was 38 dB. Based on the obtained data, it can be concluded that the studied panel recorded comparable values with other synthetic noise control solutions, which are suitable as applied cladding or an independent lightweight partition wall, with good acoustic properties.

In recent years, noise levels in administrative buildings have been considered one of the main causes of the stress and lack of productivity of employees. Based on the responses collected from a questionnaire survey distributed among companies with an open space configuration and studying the office’s acoustic conditions, from the specialized literature and through the authors’ experience, this study focused on the development of a new green dividing panel with superior sound absorption and acoustic insulation performances. In the experimental part, it was noticed that the presence of plants can influence the acoustic absorption values through their leaves’ conformation and distribution. Additionally, it was observed that the introduction of a coconut fiber layer in the panel led to higher values of the sound absorption coefficients in most of the studied plants. Through the conducted measurements, Tradescantia pallida registered superior values, with sound absorption coefficients with constantly increased values that varied in the range of 0.72–0.98 for the frequency range of 250–3150 Hz. Also, the weighted sound reduction index recorded a superior value of R_w (C; C_tr) = 27 (−1; −4) dB, comparable to other existing solutions.

The objective of this paper is to analyze the characteristics of twelve compositions based on hemp shiv and four traditional binders used in the construction industry: cement, plaster, hydrated lime and clay, with the aim of using the resulting materials as final finishing products applicable to the raw area of walls, slabs and other construction elements for walls. Comparative, cost and multi-criteria analyses were carried out on the proposed compositions. The comparative analysis focused on acoustic, thermal, mechanical and fire characteristics, followed by a cost analysis and ending with multi-criteria analysis. In general, cement presented the highest values for mechanical properties, while the other binders demonstrated the most favorable results for acoustic and thermal properties. This paper aims to provide an overview of the traditional binders used in hemp shiv composition and to examine the impact of the physical and mechanical properties of these binders on the final product.

This study aims to investigate the application of nuclear magnetic resonance (NMR) to characterize mortars containing recycled rubber waste as an eco-innovative material for sustainable construction. The primary objective was to analyze the way rubber granules influence hydration kinetics, microstructural development and pore structure. The innovative mortar formulations incorporated rubber granules, casein, natural hydraulic lime (NHL), and latex. NMR analysis revealed distinct T₂ relaxation time distributions correlated with different pore sizes and water states: shorter T₂ values demonstrate strongly bound water in small pores, while longer T₂ values are associated with loosely bound or free water in larger pores. The formulation with 3.5% NHL and 5% rubber granules exhibited optimal microstructural characteristics. These results reveal that NMR is a valuable, non-destructive tool for monitoring cementitious material evolution and supporting the use of tire-derived waste in eco-innovative mortar designs.