Comparison of Leak Detection Methods Used for Testing Large Area Membrane Roofs for Durability Assessment Purposes

This article presents different types of commercially available roof waterproofing membrane systems used on roofs with large surface area. It deals with the causes of deterioration of such membranes due to environmental factors and describes the tests used to detect leaks and determination of the severity of deterioration of polymeric membranes taking into account the properties declared by their manufactures. The last part of the article is a case study comparing a brand new membrane with a membrane after 27 years in service.

Optimizing the thickness of a straw outer wall of a building for sows in a view to achieving cost-effective heat insulation

The aim of the study is to determine the optimum thickness of the surrounding wall structure of a building for nursing sows by using heat insulation from straw and different fuel (pellets and dry wood) for heating the building. To achieve the purpose, 6 models of walls made of environmentally friendly panels with wooden skeleton, thermal insulation from pressed straw bales and double-sided clay plaster have been developed, such that the accepted thickness of the thermal insulation layer is respectively: 20, 25, 30, 35, 40 and 45 cm. The construction value of the finished wall is determined by adding the value of the construction and assembly works on the construction site to the value of the preparation of the panels (in a workshop), including the payment of labor, materials and additional costs for the implementation of clay plaster and waterproofing membrane. The annual energy losses through 1 m2 of the enclosing wall and the annual heat insulation costs (as a sum of annual energy cost and the depreciation deductions) are determined through the described methodology and verification of condensation of water vapor on the inner surface of the wall was carried out. The results of the research show that by using pellets for fuel, the optimal thickness of the thermal insulation is 45 cm, and by using dry wood it is 35, 40 and 45 cm. All studied models of enclosing straw wall meet the hygienic requirements for preventing condensation on their inner surfaces.

Performance of Waterproofing Membranes to Protect Concrete Bridge Decks

The installation of waterproofing membranes on concrete bridge decks is a commonly used strategy to prevent water on the roadway surface from penetrating into the deck and to reduce the load and freeze–thaw related damage to the bridge deck. Typically, an asphalt layer is paved over the waterproofing membrane to prevent damage from heavy vehicles. The early failure of asphalt pavement overlays on concrete bridge decks with waterproofing membranes has been recognized as a significant issue by several transportation agencies. Potential reasons for the failure of the asphalt overlay were thought to be poor adhesion between the waterproofing membrane and the asphalt wearing course, and the material properties of the asphalt layer. By determining the most effective waterproofing methods and strategies, this research will serve to decrease repair and replacement costs, and increase the service life of asphalt overlays on concrete bridge decks. The main goals of this study are to provide the industry and transportation agencies with better insight into the failure mechanisms of asphalt overlays on concrete bridge decks and to establish field and laboratory experiments to evaluate the performance of these overlays. From the results of this study, a poured waterproofing membrane was recommended as an ideal membrane for use on concrete bridge decks because of its ease of installation, complete impermeability, and high bond strengths between the concrete deck, membrane layers, and asphalt overlay.