Properties of Hydrophilic Mineral Wool for Desalination of Historical Masonry

Abstract

Hydrophilic mineral wool (HMW) is considered as a possible alternative to the commonly used cellulose in desalination of historical masonry. HMW also allows water and salt solutions transport along the hydrophilic fibres, which is the necessary condition for its possible application for desalination measures, but contrary to cellulose it is inorganic material, which reduces maintenance of the poultice. On this account, the hygric transport and storage properties of newly developed HMW is determined in the paper. In order to get detailed information on HMW performance, its thermal properties are measured as well. For its basic characterization, bulk density, matrix density, saturation moisture and salt content, and apparent total open porosity are accessed. The results are in good agreement with those published in literature for similar types of HMW. The process of drying of three different types of sandstone, as typical materials frequently used in historical buildings, using HMW board is monitored to analyse the practical applicability of the proposed desalination treatment. The obtained results show that HMW slows the drying process. However, the final level of drying is the same as without the HMW, which indicates the possible applicability of studied HMW for desalination purposes.

Salt Damage and Rising Damp Treatment in Building Structures

“…In the Laboratory of Building Physic, LFC, of the Faculty of Engineering, University of Porto, FEUP, several works have been developed that greatly contributed to the system's sizing. For over 15 years the phenomena of rising damp in building walls have been studied [85,86].…”

Characterization of the effect of wetting–drying cycles on the behaviour of hydrophilic additives in mineral wool

“…In previous research [1], the low thermal conductivity, the very low capacity of mineral wool for absorption of hygroscopic moisture, and the high water vapour diffusion coefficient were confirmed. All these properties open ways for the application of HMW products in interior thermal insulation systems, in drying-out of flooded buildings [3], and in desalination of historical buildings [4].…”

“…However, except basic physical properties, soft layer (thickness 100 mm) is used for the experiments. Fibre layers orientation was not considered in planning the experimental work, as the effect of material anisotropy on the water transport properties of the HMW was found not statistically important [1].…”

“…Practically the only notable application of HMW is in the form of synthetic soils for plant growing (green roofs as a water reservoir [2]), where water saturation of the material is necessary for its proper function. However, the capability of fibrous materials with hydrophilic substances to transport rapidly liquid water [1] make them desirable for a variety of other applications, where such favourable hygric properties can be conveniently employed.…”

“…Mineral wool based materials are frequently used in various applications, being their most widespread use in building construction for thermal insulation of walls, roofs and floors [1], and also of pipes. Additionally to its thermal properties, they can also offer acoustic insulation, protection against fire, reinforcement of cement, and they allow plant growing when used as synthetic soils in green roofs.…”