Thermo-hygrometric behavior of hempcrete walls for sustainable building construction in the Mediterranean area

Recent studies have demonstrated that the use of natural materials represents one of the pathways to achieve energy efficiency and environmental sustainability in buildings. In the framework of Circular Economy policies aimed at reducing the consumption of raw materials, shives, as an agricultural by-product of hemp cultivation, have gained a renovated life in the construction sector. Among all the building products made of hemp, hempcrete blocks are the most innovative, because they represent the solution to the needs of new and traditional buildings, offering a high energy saving, combined with the sustainability of materials and products, while remaining, in terms of shape and size, very close to the culture and the construction systems best known by professionals. In order to assess the potential benefits of hempcrete in the construction sector, its environmental performances were evaluated using the LCA methodology, following the international standard ISO 14044:2006+A1:2018 and in compliance with the European standard EN 15804:2012+A1:2013. To this purpose, four non-loadbearing walls were compared in the "cradle-to-gate" scenario, one made with hempcrete blocks and the others with more "traditional" materials. This research aims to be a basis for the development of future guidelines at national and international level in order to guarantee the maximum diffusion of this type of product also in the Mediterranean area. For this reason, it is important to identify the performance characteristics essential for hempcrete products studying their behavior not only as defined in the UNI EN ISO 12571, 2013 standard, but also in the Mediterranean climate. To achieve these objectives, some tests have been carried out to verify the thermo-hygrometric behavior. A 1 m2 of hempcrete wall was submitted to tests in a climatic chamber which simulated the environmental conditions typical of the south of Italy, in terms of temperature and moisture, in order to evaluate thermo-hygrometric behavior of hempcrete. Sensors and thermo-flowmeters for parameter analysis were applied on the wall. On the same material was carried out hygroscopic sorption tests as defined in the UNI-EN-ISO12571,2013 standard. The behavior detected by the experimental measurements on the masonry was compared with the simulated numerical behavior using WUFI software

Characterization of the kinetic behaviour of resin modified glass ionomer cements by DSC, TMA and ultrasonic wave propagation

none4Micelli, Francesco; Maffezzoli, Alfonso; Terzi, R; Luprano, V. A. M.Micelli, Francesco; Maffezzoli, Alfonso; Terzi, R; Luprano, V. A. M

Hygrothermal behaviour of hemp-lime walls: the effect of binder carbonation over time

Bio-based building materials are produced by recovering agricultural biomasses which are used as vegetal aggregate to replace traditional ones and realize more sustainable building materials. This study focuses on hemp-lime that is made by mixing a lime-based binder with hemp shives i.e. the waste of industrial hemp cultivation. The work aims to evaluate the effect of the maturation of hemp-lime on its hygrothermal performances. Specifically, the binder undergoes carbonation reaction through which the strength of the material and its hygrothermal properties develop. With this aim, two experimental campaigns were carried out on an experimental wall built using prefabricated hemp-lime blocks: the first few months after the construction and the second one after 3 years. The wall, equipped with hygrothermal sensors, was subjected to cycles at varying relative humidity values and fixed temperatures applied with the help of a climatic chamber. The cycles were performed at 23 °C and 35 °C to focus on the performances of the material in conditions comparable to those of the Mediterranean climate. The results prove that hygrothermal performances improve with maturation, which could be due to the carbonation of the binder and to the reduction of the initial moisture content. Numerical simulations of the experimental tests were implemented using the software WUFI® aiming at confirming the experimental methodology and also the possibility of simulating the behavior of such innovative material in dynamic regime. The proceeding of carbonation was proved through X-ray diffraction (XRD) and thermogravimetric (TG-DTG) analyses of samples having different maturation times

Hemp-lime buildings: thermo-hygrometric behaviour of two case studies in North and South Italy

In the framework of Circular Economy policies aimed at reducing the consumption of raw materials, shives, an agricultural by-product of hemp cultivation, have gained a renovated life in the construction sector; new building materials, suitable for various executive techniques, have been developed exploiting the excellent thermal insulating properties of shives. When this vegetal material is mixed with a mineral binder such as lime or cement, the mixture is usually referred to as hemp-lime. In Italy, the use of hemp-lime blocks and the development of new production chains dates back only to about the last decade, while other European countries have more long-lasting experiences. In order to assess the potential benefits of hemp-lime blocks in the construction sector, it is necessary to evaluate the performance of these materials in situ, i.e. on the construction site, to obtain fundamental data to ensure that consumers and designers receive trustworthy and relevant information on products and their durability. This research work aims to be a solid base for the development of future guidelines and/or regulations at national and international level, in order to guarantee the maximum diffusion of this type of product. Then, a study plan has been carried out regarding the functionality of hemp-lime blocks in masonry, layered with finishing plaster made of fine hemp shives, to evaluate the in situ thermo-hygrometric building performance. In particular, experimental methods were developed and measurements were carried out on two structures, one in northern Italy and one in southern Italy, and precisely in Sicily, focusing the study on the performances of the walls subjected to warm Mediterranean climates

Physical Chemistry Supports Circular Economy: Toward a Viable Use of Products from the Pyrolysis of a Refuse-Derived Fuel and Granulated Scrap Tire Rubber as Bitumen Additives

The production and maintenance of road pavements consume resources and produce wastes that are disposed of in landfills. To make more sustainable this activity, we have envisioned a method based on a circular use of residues (oil and char) from municipal solid waste pyrolysis as useful additives for producing improved asphalts and for recycling old asphalts to generate new ones, reducing at the same time the consumption of resources for the production of new road pavements and the disposal of wastes to landfills. This work aims to show the feasibility of the integration of two processes (thermal treatment of municipal solid waste on one side, and that of road pavement production on the other side) where the products deriving from waste pyrolysis become added-value materials to improve the quality of road pavements. In this contribution, we presented the effect of pyrolysis product addition on asphalt binder (bitumen) preparation and aging. Solid and liquid products, deriving from the pyrolysis of two kinds of wastes (refused derived fuel (RDF) and granulated rubber tyre waste), have been used for the preparation of asphalt binder samples. Rheological tests have been performed to determine the mechanical properties of neat asphalt binder (bitumen) and those enriched with pyrolysis derived products. Measurements to evaluate possible anti-aging effects have been also performed. The collected results indicate that char addition strengthens the overall bitumen intermolecular structure while bio-oil addition exerts a rejuvenating activity