Preservation of cultural heritage is gaining increasing attention all over the world. Restoration of ancient artwork and architecture requires even more effective cleaning techniques than are currently available. Laser cleaning appears to be a suitable method for removing surface contaminants from porous materials like masonry. This paper presents some effects of laser beam interaction (ruby laser, free generation regime) with clean and contaminated surface of brick which ...
Atmospheric corrosion of building materials is an enormously complex and interdisciplinary process. It affects not only the ability of building to perform over the prolonged period of time but also the overall energy consumption. The presented paper is a part of a larger study on application of acrylic plasters in passive solar systems. Absorption characteristics as well as microstructural features of acrylic plasters subjected to alternating climatic conditions have been ...
condensed matter physics
This paper presents results which are part of a larger study on the influence of two admixtures (methyl hydroxy ethyl cellulose, MHEC, and polyvinyl acetate, PVA) on properties of water contained in pores and capillaries of cementitious materials subjected to freezing and thawing. An attempt has been made to explain some aspects of frost deterioration based on the Everett and Hynes model of phase transition. The Differential Scanning Calorimetry technique was used to recor...
This paper presents the results of the larger study on the potential application of laser radiation for the detection of phase transition processes. The proposed experimental method allows a dynamic study of the phenomena without mechanical intervention. This seems to be the best practical solution particularly when the access for the other methods is very restricted. The investigations give an evidence of the strong relationships between the rapid growth of water vapour c...
Alternating environmental conditions not only influence the long-term performance of construction materials but also the overall energy consumption. Humidity in building partitions has particularly strong effect. Condensation of water vapour and subsequent absorption of water adversely affect thermal properties and, if persistent may lead to the severe deterioration of building envelop.This paper presents the results of a non-contact dynamic study of the condensation proce...
komputerowe wspomaganie projektowania
The optimisation approach to any activity in technology, economics or other fields, is aimed at finding methods of determining the best solutions in an objective way. In particular, the optimisation of composite materials deals with problems of selecting the values of several variables which determine composition, microstructure, mixing procedure and curing regime, etc. This paper presents the application of the optimisation approach to the design of frost resistant concre...
This paper presents the results of the larger study into a potential application of laser radiation for the detection of phase transition processes in low temperatures occurring on the surface layers of cementitious materials. An attempt was made to identify relationships between the environmental conditions-temperature and air humidity, and the selected parameters of the reflected light. Onset of the condensation process and formation of water microdrops on the surface of...
education in hong kong
This paper presents an example of the optimisation of two building arrangements as a function of three variables describing their alignment relative to each other and relative to North. The presented results are limited to the wind flow speeds around buildings in flat undeveloped terrain. The turbulence model K-ε has been adopted for this study. Calculations have been made with the use of simulation program FLUENT 4.3.The potential application of a multicriteria optimisati...
Deterioration of mortars by weathering is usually of great importance and is brought about by the disruptive action of alternate freezing and thawing of free water within the material. As it appears that applications of methyl hydroxy ethyl cellulose (MHEC) and polyvinyl acetate (PVA) are very beneficial in improving frost resistance, special attention has been paid to observing the changes in microstructural features of polymer modified composites exposed to the destructi...
This paper reports results from a larger study on the influence of two admixtures (methyl hydroxy ethyl cellulose, MHEC and polyvinyl acetate, PVA) on properties of water contained in pores and capillaries of cementitious materials subjected to freezing and thawing cycles. The Differential Scanning Calorimetry technique has been found to be particularly useful in evaluating the amount of heat that is involved as material undergoes either an endothermic or an exothermic tra...