Salt damage can affect the service life of numerous building structures, both historical and contemporary, in a significant way. In this review, various damage mechanisms to porous building materials induced by salt action are analyzed. The importance of pretreatment investigations is discussed as well; in combination with the knowledge of salt and moisture transport mechanisms they can give useful indications regarding treatment options. The methods of salt damage treatment are assessed then, including both passive techniques based on environmental control, reduction of water transport, or conversion to less soluble salts and active procedures resulting in the removal of salts from deterioration zones. It is concluded that cellulose can still be considered as the favorite material presently used in desalination poultices but hydrophilic mineral wool can serve as its prospective alternative in future applications. Another important cause of building pathologies is the rising damp and, in this phenomenon, it is particularly severe considering the presence of salts in water. The treatment of rising damp in historic building walls is a very complex procedure and at Laboratory of Building Physics (LFC-FEUP) a wall base hygroregulated ventilation system was developed and patented.
1 February 2019 in Renewable and Sustainable Energy Reviews
Effective thermal conductivity of hollow bricks with the cavities filled by either air or expanded polystyrene is analyzed using a hybrid experimental–computational approach. The experimental setup involves an application of a thermal insulation box and a set of temperature and heat flux probes placed at characteristic positions of the specimen-insulating box system. Using the measured heat fluxes and temperatures, the heat loss of the system is determined. A computer simulation tool based on the finite element principle is then used for modeling the temperature fields and heat losses in the studied system. Finally, the effective thermal conductivity is identified using an iterative procedure. Experimental results show that the application of expanded polystyrene as cavity filler instead of air leads to ∼30% decrease in the effective thermal conductivity of hollow brick blocks.