Physical and mechanical properties of composites based on hemp shives and lime

Abstract

Abstract.One of the objectives of sustainable development in construction is the use of low-processed materials. They have a positive impact on the ecological balance of the building throughout the entire life cycle. Examples of such materials are materials of plant origin -straw, shives, cellulose fibers. They are used as thermal insulation or wall material. In recent years, hemp shives are increasingly used as a component of a lime-based composite, which performs the function of wall filling in timber frame constructions. The shives, due to the high porosity, determine the high thermal insulation properties of the composite. The physico-mechanical properties of the composite can be modified depending on various factors, including the ratio of hemp shives to the binder. The lime binder, in turn, can be modified by hydraulic and pozzolan additives. The paper presents mechanical properties (compressive and flexural strength) as well as physical properties (density, porosity, thermal conductivity coefficient, absorbability) of composites with various proportions of hemp shives of the Bialobrzeskie variety to the lime binder modified with Portland cement and metakaolinite.

Capillary Uptake Monitoring in Lime-Hemp-Perlite Composite Using the Time Domain Reflectometry Sensing Technique for Moisture Detection in Building Composites

“…Metakaolin was a highly reactive pozzolanic material, which was formed in the kaoline clay calcination process under controlled temperature conditions of around 600-850 • C. Its main ingredient was hydrated aluminum silicate Al 2 Si 2 O 5 (OH) 4 . This additive has been used in other studies of the hemp-lime composite [35].…”

“…Its main ingredient was hydrated aluminum silicate Al2Si2O5(OH)4. This additive has been used in other studies of the hemp-lime composite [35]. The formulas of the tested composites are presented in Table 1 (amounts by weight per 1 m 3 ) and in Table 2 (proportions by weight).…”

Investigation on a Bio-Composite Material as Acoustic Absorber and Thermal Insulation

“…There are some studies based on the same topic in the literature [20][21][22][23]. Hamzaoui et al recently investigated the mechanical performance of mortar, considering the addition of hemp [20].…”

“…The physical and mechanical properties of composites based on hemp shives and lime have been assessed by Przemysław Brzyski and Grzegorz Łagód in [23]. In detail, mechanical, thermal, and hygroscopic tests have been carried out on lime and hemp shives-based specimens.…”

VOC Emissions from Spruce Strands and Hemp Shive: In Search for a Low Emission Raw Material for Bio-Based Construction Materials

“…Furthermore, lime-hemp materials contribute to CO 2 emissions reduction. CO 2 is absorbed while hemp is planted as well as during the process when slaked lime is curing into limestone (calcium carbonate) again [22,27,28].…”