This article is focused on the analysis of the use of distributed fibre-optic technology for security monitoring of road tunnel and motorway tunnel structural load. The authors focused on the measurements of deformation utilizing Brillouin Time Domain Reflectometry (BOTDR). The principle is based on the measurement of stimulated Brillouin scattering. The article describes and analyses real measurements within a period of 5 months, which were carried out during the tunnelling and the whole process of building a new tunnel inŽilina, Slovakia. The performed experimental measurements were carried out using a standard optic telecommunication cable with water-absorbing aramid yarns and a jacket with a diameter of 4.2 mm. The contribution of this article lies in the introductory analysis of the implementation and use of the fibre-optic technology for security monitoring of road tunnel and motorway tunnel structural load.K e y w o r d s: Brillouin time domain reflectometry (BOTDR), fibre-optic sensor

Alkali-activated materials are formed by the alkaline activation of inorganic materials and are characterized by the wide range of potential use. The objective of experiment was to investigate the possibility of use fine-grained alkali activated composites in the construction industry. Selected properties of alkali-activated systems based on granulated blast furnace slag and fine-grained aggregates were determined. At the beginning of the experiment, different samples prepared of 3 types of activators were tested, basic properties (time of workability, initial and final setting time, compressive and flexural strength) and also a possibility of selected retarder use was determined. Then, samples with the best potencial to presumed use were tested in detail and a possibility use as a substitute for selected construction materials were evaluated. On the basis of determined properties, prepared composites could be used as reprofiling mortars, materials for cracks repairing or socle plasters.

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Alkali activated concrete (AAC) are considered a promising building material. They show high strength, good durability, and good resistance to aggressive agents etc. But these good properties are controlled by the good design of the concretes. The paper presents the results which were recorded for self-compacting AACs with the water to slag ratio 0.50 - 0.52. The resistance of these concretes to Na2SO4, NH4Cl and acetate acid is presented in this paper. These agents were selected because they represent agents which are present in compost or sewage.