Experimental Investigations on the Performances of Composite Building Materials Based on Industrial Crops and Volcanic Rocks

Abstract

Interdisciplinary and sustainability represent the main characteristics of this paper due to the fact that this research is offering a connection between two main areas-agronomy and construction, by using hemp shiv for the design of new building materials, which can increase the sustainability level of the building industry. For this reason, the main scope of this study is based on the investigation of a new category of composite building materials-lightweight mortars based on hemp shiv, volcanic rocks and white cement-which contribute to a positive environmental impact and help to increase indoor comfort. A complex report was carried out on two segments. The first one is focused upon the characteristics of the raw materials from the composition of the new materials, while the second segment presents a detailed analysis of these composites including morphological and chemical investigation, pyrolytic and fire behavior, compression and flexural strengths, and acoustic and thermal characteristics. The proposed recipes have as a variable volcanic rocks, while the hemp and the binder maintain their volumes and properties. The results were analyzed according to the influence of volcanic rocks on the new composites.Crystals 2020, 10, 102 2 of 21 consideration in the construction sector. There is a significant number of studies on hemp shiv with lime, which is a composite material named hempcrete [12][13][14], but there are only few studies that concern hemp shiv with cement [15][16][17][18][19].Due to the fact that hemp shiv presents poor fire resistance, a new approach can be made with volcanic rocks, which are natural products with higher fire resistance [20]. These materials are usually found in the composition of mortars used in the rehabilitation process of the walls, because of their increased mechanical resistances [21]. They also present sound and thermal properties, as well as a low density, which will help the workability of the mortar. Durable and with higher strength properties for structural application [20], volcanic rocks are low cost materials [22] that also present fire retarding properties for steel structures [23].Therefore, the purpose of this paper is to analyze the impact of the volcanic rocks when these are incorporated in hemp-cement composite materials used as interior mortars. These building materials are developed to be suitable not only for eco-friendly construction but also in regular buildings made from concrete, steel, and so forth, where they can increase indoor comfort. Materials and Methods Raw MaterialsThe composition of the new materials is designed to increase indoor comfort by developing new types of lightweight mortars, obtained as prefabricated plates. In order to understand the characteristics of the new composites, hemp shiv, natural and treated; volcanic rocks, perlite and vermiculite; and binders, white cement and hydrated lime, were analyzed. Hemp ShivThe hemp shiv used for the new composites was received from HempFlax Romania (Pianu De Jos, Alba, Romania). The chemical stru...

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