Concrete is the material of basic significance in building construction. It also plays essential role in agriculture and food industry. The aim of this study was to compare selected properties of a concrete mix and mature concrete, depending on the percentage of silica dust (microsilica). The greatest potential for reuse of waste has the building materials industry. There was designed a concrete with the composition as for the C20/25 concrete without any silica dust as well as three concrete types containing respectively 5, 10, 15% silica dust. The concrete mixes were subjected to the slump test and air content test, the matured concrete h compressive and bending strength test, the test of penetration depth of water under pressure, water absorption test and frost resistance test. The investigations showed the usefulness of silica dust as a material for the production of concrete.

The study presents investigations results on economic situation of farms from district Radzyń in Poland, based on the 2014 data. The survey study involved 20 different farms concerning their conditions, possibilities and capability for production. It was stated that most farmers in the county Radzyń plans to use the share of loans in investment as well as express their willingness to use aid programs after 2014. It was found that the farms of an area exceeding 10 hectares have a developing character. The financial situation of households is associated with a production setting. The best of the budgetary situation turned out to be farms specialized in animal breeding and milk production.

In the paper the review and comparative characteristics of coal, natural gas, fuel oil and biomass fired stoves and boilers with short combustion cycle and boilers fixed with automation and dosing system providing the operating without service during continues working was presented. Gas and oil boilers equipped in open and close combustion chamber with condensation and also multifuel boilers were analysed. Coal products fired boilers have various structures of combustion chamber, heat exchangers, air supply and exhaust fumes exits. Theirs efficiency is not high. Basic fuel in Polish energetics is hard coal in various assortment. For this reason the most amount of solutions for boilers was created thinking about using this fuel. Undoubtedly the most convenient are self acting natural gas boilers. Alternative is fuel oil ones. The new solution providing diversification of charging sources are mulifuel fired boilers, expensive and rare on our market yet.

This paper presents the problem of sulphate corrosion in the sewage network systems. The sulphate corrosion and its consequences are presented. The issue of biological corrosion, sulphate reducing bacteria (SRB) and sulphur-oxidizing bacteria (SOB) as the two main groups of microorganisms participating in the process of sulphate corrosion is described. Subsequently hydrogen sulphide was characterised and stages of sulphate corrosion leading to the formation of ettringite (hydrous calcium aluminium sulfate) were presented. At the end a possible protection against the sulphate corrosion was outlined. It has been concluded that sulphate corrosion is a serious threat to the sewage network systems.

Aim of the research is analyze of investments in technological equipment for selected farms in the years 2007–2013. Questionnaire survey were carried out in 30 farms in the province of Malopolska. In paper were determined: the amount of investment, source of funding and the replacement index machinery stock. The main source of capital for investment were the own resources. In the analyzed period, 62% of farms modernized technical means, 30% in slightly renewed machinery, while 20% have a modern machine park.