Browse

Concrete and mortar made with Portland cement can be damaged when exposed to solutions containing sulphate. Waste water ofte n contains sulphuric bacteria, and so the piping is frequently damage due to sulphate attack. In case of concrete sewer pipes this phenomenon is caused mainly by the sulphur-o xidising and sulphate-reducing bacteria that are forming part of the biological circulation of sulphur and its compounds in biosphere. These bacteria take part in the dissimilatory part of this cycle and the bacterial ...

The cement as a building material significan tly affects the environment throughout the whole life cycle. The environmental assessm ent of products should be a factor of importance in term of protection of the e nvironment and human safety. Environmental assessment of type I which determines the criteria for materials and products is the most used evaluation process in Slovak Republic. Cements environmental criteri a within the Slovak eco-lab elling process include the energy consumption limitation for production ...

Building industry has an essential share in depletion of environment and, after food production, belongs to the largest consumer of raw materials. Exploitation, production or transportation of building materials, as well as build-up, operation or demolition of buildings requires massive amounts of energy and results in huge amounts of greenhouse or acidifying gasses emission, par ticipates in depletion of ozone layer, eutrophication processes or photochemical ozone creation. Selection of building materials, as pri...

Mine activity and acid mine drainage formation is one of the biggest environmental problems related not only to environment components influence (soil, biosphere, plants and surface water) but also to man-made materials as concrete degradation because of its chemical composition and microorganisms’ content. Corrosion associated with microorganisms has been recognized for over 50 years and yet the study of microbial involved corrosion is relatively new. Generally, microbial involved corrosion is caused by the exc...

The incorporation of industrial by-products such as fly ash, slag, silica fume in concrete can significantly enhance its basic properties in both the fresh and hardened states. These materials greatly improve the durability of concrete through control of high thermal gradients, pore refinement, depletion of cement alkalis, resistance to chloride and sulphate penetration, and continued microstructural development through a longterm hydration and pozzolanic reaction. The utilisation of by-products as the partial rep...

The presence of aerosol particles is strongly related with increased morbidity and mortality even at the ordinary aerosol concentration levels that occur in the urban environment. Aerosols contamination of indoor environment can originate from both outdoor and indoor sources (cooking, smoking etc.). Dangerous effect of particles consists in their penetration and deposition into human respiratory system. Because of inhalation exposure not only particulate size is important, but also particulate matter’s chemical ...