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Raw earth bricks made from the soil of the Chalky Champagne region (France) have been used for at least two millennia in construction, a promising heritage in the context of reducing the carbon emissions of buildings. The present experimental study aims to measure the physical, mechanical, thermal, and hydric properties of adobes collected from a local village barn. The results show a high chalk content, estimated at 71%, and a clay content, acting as a binder, of 14%. Despite limited load-bearing capacity, these lightweight adobes are suitable for current single-story constructions, while their hydrothermal properties classify them as excellent moisture regulators for occupants. In association with other bio-sourced materials such as starch–beet pulp bricks, Chalky Champagne adobes yield promising insulating properties, and meet the criteria defined by current energy standards. [ABSTRACT FROM AUTHOR]

This paper presents the first laboratory study of four materials (three lateritic soils and one sandy soil) mainly used in road construction in French Guiana. The analysis of macroscopic behaviour by physical tests, following French standards, made it possible to classify and group the samples with respect to the rules specified in the Guide des Terrassements Routiers (GTR). According to the GTR, these raw materials could only be used as backfill materials and under very specific hydric conditions. Chemical and mineralogical characterisation by the X-ray fluorescence analysis, scanning electron microscopy observation supplemented by the X-ray microanalysis, and the infrared analysis revealed differences in the main minerals. Indeed, the presence of mineral species such as kaolinite and gibbsite and oxides such as goethite and hematite was detected. The macroscopic and microscopic characteristics of the four soils made it possible to establish a relationship between their geotechnical and mineralogical properties. Finally, the results of this study led to the conclusion that the mineralogical composition and geotechnical properties of lateritic soils must be known simultaneously to allow correct identification for their application in road construction. [ABSTRACT FROM AUTHOR]

The gradual development of government policies for ecological transition in the modern construction sector leads researchers to explore new alternative and low environmental impact materials with a particular focus on bio-sourced materials. In this perspective, the mechanical, thermal insulation, and the sound absorption performances of a spent coffee grounds/potato starch bio-based composite were analyzed for potential application in buildings. Based on thermal conductivity and diffusivity tests, the coffee grounds waste biocomposite was characterized as an insulating material comparable with conventional thermal insulation materials of plant origin. Acoustical tests revealed absorption coefficients in the same range as other conventional materials used in building acoustical comfort. This bio-sourced material presented a sufficient compressive mechanical behavior for non-load-bearing structures and a sufficient mechanical capacity to be shaped into building bricks. Mechanical, thermal, and acoustic performances depend on the moisture environment. The groundwork was laid for an initial reflection on how this composite would behave in two opposite climates: the continental climate of Reims in France and the tropical climate of Belém in Brazil. [ABSTRACT FROM AUTHOR]

One possible approach to reducing the environmental impacts associated with the building sector is the development and use of bio-based building materials. The objective of this study is to determine the water properties of bio-based insulation materials, derived from winegrowing co-products, which promote energy efficiency. The water performance of these new bio-based materials is based on the measurement of the moisture buffer value, the sorption isotherm, and the water vapor permeability. Four by-products are analyzed: stalks, grape pomace, crushed stalks, and skins; they are combined with a potato starch binder. The performance of these composites is compared to two other bio-based composites (hemp/starch and beet pulp/starch). The stalk/starch composite can be classified as a hygroscopic and breathable material with excellent moisture retention capacity. [ABSTRACT FROM AUTHOR]

This article concerns the elaboration and the characterization of a novel biobased potato starch-beet pulp composite for packaging applications as cushion foams. A twin-screw extruder was used to elaborate composite foams. SEM observations of these materials were conducted, and thermomechanical properties were studied in terms of thermal transitions (TGA, DSC) and viscoelastic properties (DMA). The effect of relative humidity content on viscoelastic properties was analyzed as a function of frequency. The different test results show that the composite structures are homogeneously mixed. The sponge-like structure of the beet-pulp disappears indicating a good compatibility between the two mixed constituents. The DSC curve of starch-beet pulp foam shows a single thermal transition at 153.6 °C, indicating the thermal homogeneity of the obtained composite material. The density value of starch-beet pulp foam is higher than conventional foams, but this can be optimized by adjusting the technological parameters of the extruder. The viscoelastic properties of the developed materials depend on the relative humidity. [ABSTRACT FROM AUTHOR]

This article deals with the elaboration and the characterization of an innovative 100% plant-based green composite made solely of beet pulp (BP) and potato starch (S). Using this type of material in insulation applications seems a good solution to reduce the CO2 gas emissions in building. The influence of the starch amount on composite characteristics was studied. Four mixtures were considered with different S/BP mass ratios (0.1, 0.2, 0.3 and 0.4). The physical properties of these materials were studied in terms of porosity, apparent and absolute densities, thermal conductivity, and hygric properties. The influence of humidity content on acoustical properties was studied as a function of frequency. Test results show a real impact of both starch and humidity contents on the hygrothermal and acoustical properties of the studied material due to the porosity. The composite with the lowest amount of starch (S/BP = 0.1) seems to be the optimal composition in terms of the hygrothermal and acoustical behaviors. [ABSTRACT FROM AUTHOR]