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Highlights • This study shows the mechanical performance of the beet pulp composite materials. • The binding strength of the beet pulp composite depends on the material density. • The beet pulp composite shows a good thermal and acoustical properties. • The beet pulp material is classified as an excellent hygric regulator. Abstract This work deals with the making of a new renewable green material for building insulation from sugar beet pulp and potato starch. The material is both lightweight and ecofriendly. The influence of starch/extruded sugar beet pulp mass ratio (S/EBP) is studied. Four mass ratios are considered, 10, 20, 30 and 40% (relative to the starch). Samples are characterized in terms of absolute and bulk density, sound absorption coefficient, compressive and flexural strength, as well as and hygrothermal properties (the moisture buffering value and thermal conductivity). The sound absorption coefficient shows that this material is a good sound absorber, especially in medium and high frequencies. The sound absorption capacity depends on the fiber content and the humidity content. The best values are between 0.6 and 0.8. The compressive strength increases linearly with the S/EBP weight ratio to reach 0.52 MPa and the compressive strain is 30%. The elasticity modulus and the Poisson's ratios were also studied. The transversal and vertical strain were measured using ARAMIS optical system. The moisture buffering value was measured according to Nordtest Protocol. The recorded moisture buffering value was between 2.6 and 2.8 g/(%RH.m2) and shows that the sugar beet pulp-starch composite is an excellent hygric regulator. The thermal conductivity is to around 0.070 W/(m·K). The results obtained shows that increasing starch amount tends to decrease composite porosity but increases thermal conductivity and mechanical properties. Depending on the starch content, beet pulp composites have a good thermal and acoustical performance and can be used as building materials. [ABSTRACT FROM AUTHOR]

Following the environnement grenelle, reaching 10% of bio-resourced materials in building sector except wood is one of goals until 2020. Among these agro-materials, one can distinguish the hemp concrete. Based on hemp hurds and mineral binders including lime or polymer as starch, the hemp composites are appreciated for their hydrothermal and acoustic properties. In this study, a vegetal binder based on starch and extracted from wheat is used with treated and non-treated hemp hurds to form an ecological composite. The studied hemp-starch is prepared with a ratio (H/S = 3,3). Hygrothermal properties such as moisture buffering value, sorption isotherm, water vapor permeability, thermal conductivity, and heat capacity are experimentally studied. The pore size distribution is performed using mercury porosimetry. Results reveal that the hemp-starch composite may be a promising solution in the insulation field due to its relatively low thermal conductivity and capacity to regulate the indoor relative humidity. [ABSTRACT FROM AUTHOR]

This paper presents the results of a laboratory investigation into the hygric properties and moisture buffering performance of hemp-starch composite panels designed for building applications. Composite panels were produced by bonding hemp shiv with wheat starch as a binder. Two types of hemp shiv were tested: chemically processed shiv with enhanced adhesion between fibers and starch matrix, and non-treated shiv. The panels were then characterised in terms of their hygroscopic properties (sorption curve and vapour diffusion resistance factor) and their moisture buffering performance (moisture buffering value, MBV). The determination of theoretical MBV was based on the effusivity of the material, which is obtained from its basic hygroscopic characterisation. The results show that both panels are excellent hydric regulators that can be used to improve indoor hygrothermal comfort by buffering indoor relative humidity variations. [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 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]

• This paper explores the effect of embedding PCM in sugar-beet-pulp/starch bricks. • Experimental measurements and 3D heat transfer simulations were done. • The 3D heat transfer simulations closely follow the experimental measurements. • The embedded PCM leads to increased thermal inertia of the bricks. • This effect is only practically relevant for walls made of one layer of bricks. Due to environmental concerns, bio-based materials are being increasingly investigated and used in buildings. In general, the density of these materials, and thus their thermal inertia, is low. Thermal inertia can be beneficial for reducing the energy use of buildings by damping indoor temperature fluctuations or by reducing and delaying incoming (solar) heat through the façade. This study explores the thermal inertia of regular-sized bricks made of a sugar-beet-pulp/starch mixture (BP/S), and with 17 circular holes inside. The holes were filled either with the BP/S mixture, with air, with a stabilised phase change material (PCM) gel or with a salt-hydrate based PCM. The brick was insulated on all sides but one. Two series of experimental measurements were performed: 1.) a heating film placed at the back (insulated) side of the brick heated the brick until steady-state conditions were reached; 2.) the heated brick was then passively cooled down to ambient temperature by cutting the power to the heating film. Numerical simulations of these experimental measurements were also modelled using the COMSOL Multiphysics® software. In addition, simulations were run to study the thermal inertia of a full brick wall made out of 1 layer and of 4 layers of the BP/S brick with and without PCM, exposed to a combination of a sinusoidal outdoor air temperature fluctuation with an imposed radiation flux on the outdoor surface, representing summer conditions. The results show that the brick in which the holes were filled with phase change material had a slower temperature response and thus higher thermal inertia than the bricks in which the holes were filled with BP/S or with air. The salt-hydrate based PCM with the higher latent heat of fusion led to the slowest temperature response and highest thermal inertia. Furthermore, the calculated simulations could accurately reproduce the experimental measurements. Applying PCM in thick walls (40 cm) made of BP/S bricks however hardly affects the temperature amplitude damping and time delay of the complete wall. The addition of PCM therefore is only effective for thinner walls (10 cm). [ABSTRACT FROM AUTHOR]

• Two types of beet-pulp/starch bricks are investigated: full and hollowed bricks. • The preparation of the mixture and bricks manufacturing are described in details. • The microstructure of the mixture constituents are described and analyzed. • The drying kinetics of the bricks are compared and predicted via mathematical models. • The mechanical behavior of the bricks is studied via compressive tests on each type. Buildings account for a large share of the primary energy and materials use in Europe. Therefore, the EU has set several energy and materials targets for the built environment and other sectors. Novel low-carbon materials can play a major role in the transition towards meeting those targets. Moreover, agriculture produces by- or waste products that could be used as constituent of innovative agro-materials for construction. Recently, beet pulp based-material is being investigated on the material scale and promising results are pointed out regarding its interesting mechanical, hygrothermal and acoustical properties for building insulation use. In this context, the paper aims to study experimentally two types of beet-pulp starch composites: whole bricks and hollowed bricks. The manufacturing of the two types of bricks is detailed. A comparative study is then achieved regarding the drying kinetics, mechanical properties as well as internal structure composition. [ABSTRACT FROM AUTHOR]