Nowadays one of the main tasks of environmental protection is the management and recycling of plastic waste. Plastic occupy the major part of all public waste and with this material is polluted all earth. In natural condition plastic decompose in 400 or even in 500 years. Therefore, it is important to solve this problem reusing plastic waste. One of the possible areas is construction industry. In the present paper were estimated how plastic waste impact the properties of concrete. During the research the part of coarse aggregates were changed with polyethylene (PE) pellets and cut polypropylene (PP) particles. The change of fresh concrete density, workability and hardened concrete density, compression strength, water absorbability were evaluated. The results show, that plastic waste has a positive effect on fresh concrete properties: the concrete become more workable and lighter. Unfortunately, on the main hardened concrete properties the increase plastic waste amount has the negative effect: the compression strength was decreasing and the water absorbability was increasing. However, generalizing all results, can be stated, that keeping the same level of concrete workability there are possibilities to reduce water and cement ratio and it will give strength loss and water absorbability growth compensation.

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Cracks are classified according to their geometry (length, width and depth), statistical parameters (mean and variance of the number of cracks per unit area), crack riskiness for structures, etc. In this paper, crack openings in a reinforced concrete shell of the pressure piping at Kruonis Pumped Storage Power Plant, which appeared due to temperature change, are analysed. Detailed analysis of cracks and deformations due to temperature changes was performed after the evaluation of the technical state of the pipeline. Specific illustrations, calculations and guidance for repair of these deteriorations were offered.

Sustainable (environmentally friendly) modern construction is not limited only to use of natural and environmentally friendly materials. The concept of the construction is an important factor and that is applied to local materials, especially if they come from renewable sources. The sustainable (environmentally friendly) building principles, methods of construction from straw, the essential building requirements for construction from straw are discussed in the article. Straw as a building material used for a very long time, but this usage is often associated with certain mistrust, fears: the building will burn, the mice, rats are attacking, etc. Straw building uses raw materials which are agricultural waste. Buildings constructed from straw decompose in the end of their lifecycle and the construction waste in the area of construction is biodegradable, consequently, it is not necessary to take them away to a landfill. The evaluation of the global and Lithuanian experience of using straw and the structures in which straw are used shows, that the essential requirements can be provided if the straw and timber-framed buildings with straw as a heat insulating material are constructed properly, they use to meet the essential requirements according to the Law on Construction and the European Council and Parliament Regulation No 305/2011.