Zbigniew Suchorab, Danuta Barnat-Hunek, Piotr Smarzewski, Zbyšek Pavlík and Robert Černý
The article presents information about moisture protection of building materials. The discussed parameters determining the efficiency of the water protection are material porosity, water absorptivity and surface condition of building materials. Moreover the ecological aspect of hydrophobic VOC-free preparations available on the market has been underlined. The first part of the article is a description of moisture problem in the building envelopes and the possibilities of its prevention. The special attention is put on the electric methods of moisture estimation with a special emphasis on the Time Domain Reflectometry (TDR) method. The second part of the article is devoted an experiment of model red-brick walls exhibited on capillary uptake process. For the experiment three model red-brick walls were built and prepared for water uptake process. The experiment was monitored by the capacitive and surface TDR probes thanks to which the necessity of sampling and material destruction could be avoided. Conducted experiments show the progress of water uptake phenomenon in the model walls which differ in type of protection against moisture and prove the potential of the non-invasive measurements using the surface TDR probes. Basic physical parameters of the applied bricks were determined together with the reflectometric measurements. Furthermore, Scanning Electron Microscopy (SEM) was used to analyze the hydrophobic layer continuity.
Zbigniew Suchorab, Danuta Barnat-Hunek, Małgorzata Franus, Grzegorz Łagód and Zbyšek Pavlík
The article presents the laboratory investigations of the basic thermal and hygric parameters of standard lightweight aggregate-concrete and lightweight aggregate-concrete supplemented with municipal sewage sludge. Both types of concrete are based on light aggregates, commonly used in the Polish building market. In order to improve the hygric parameters of the material, such as water absorptivity, the admixture of water emulsion of reactive polisiloxanes was applied. Within the presented research, together with basic moisture parameters estimation, capillary rise process was monitored using Time Domain Reflectometry (TDR) modified sensors. Hygric parameters were supplemented with the estimation of thermal conductivity coefficient λ determined using stationary method. The analysis of thermal and hygric properties of concrete confirmed the applicability of lightweight aggregate-concrete with sewage sludge supplementation for further production.