The use of industrial residues to replace natural resources for the production of building materials is economically and ecologically justified. Fly ash (FA) taken directly from electro-filters is commonly used as a cement replacement material. This is not the case, however, for old dumped fly ash (ODFA) that has been accumulating in on-site waste dumps for decades and currently has no practical use. It causes environmental degradation, which is not fully controlled by the governments of developed countries. The aim of the study was to assess the possibility of using ODFA as a partial replacement for sand in cement composites. ODFA replaced part of the sand mass (20% and 30%) in composites with a limited amount of cement (a cement-saving measure) and sand (saving non-renewable raw material resources). ODFA was activated by the addition of different proportions of hydrated lime, the purposes of which was to trigger a pozzolanic reaction in ODFA. The quantitative composition of the samples was chosen in such a way as to ensure the maximum durability and longevity of composites with a limited amount of cement. The 28-day samples were exposed to seawater attack for 120 days. After this period, the compressive strength of each sample series was determined. The results suggest the possibility of using ODFA with hydrated lime to lay town district road foundations and bike paths of 3.5 to 5 MPA compressive strength. What is more, these composites can be used in very aggressive environments.

Construction activity with a huge variety of structures, forms and conditions underlying the implementation of construction projects, require special management approach. Decisions are most often made at the planning and preparation stage of a construction project. The literature on the subject includes descriptions of decision support methods and models, including single-criteria and multi-criteria models, operations research and fuzzy models. Different models can be used in different situations. The article contains an analysis of model approaches proposed in the literature, confronted with decision-making processes in engineering practice. The study covered 34 construction projects and 15 companies operating in the construction industry. Several decision situations have been considered. The research carried out in accordance with the seven-stage research process has shown that although the various methods proposed in the cited sources can be used in the implementation of engineering projects, they require modification to suit the specificity of engineering practice. The results of the research are the decision support models proposed by the authors, adapted to the conditions in which construction projects are implemented. In the case of small and relatively simple construction projects, simplified models are usually used, where the use of the last steps of verifying the results and improving the applied model is limited. Large and more complex construction projects were often accompanied by a decision support system consisting of more stages, and in these cases, it turned out to be important to obtain feedback and to refine the decision model accordingly. Research has shown that in large projects it is important to obtain feedback. This is due to, inter alia, from the fact that the implementation of these projects involves much greater financial resources than in small and medium-sized projects. Decision-makers take much more care to verify the correctness of the model, because the effects of wrongly made decisions can be much more severe than in the case of small and medium-sized enterprises. If it is necessary to make strategic decisions related to the future of a given company, attention was paid to models in which the starting point was to clearly define the goal and collect a complete set of information about the decision-making environment. Various analytical and research methods were used, but feedback was always needed to improve the final solution. The observations obtained during the research helped the authors to develop decision support models dedicated to engineering practice that may be useful in the implementation of construction projects.

A building investment, especially in nature valuable areas, is almost always inseparable with a bigger or smaller environmental interference. For a few years there are legal regulations created to protect these areas. One of them is the requirement to conduct a habitat evaluation and to prepare a habitat report if there is a indication of significant impact on the Natura 200 site. The quality of such a report is crucial for completion an investment in a chosen localisation as well as for shortening a preparation stage with respect to environmental requirements. A defective report can result in a agreement refusal of investment completion conditions of an investment by an authorised body, and can be a reason for protests of a community which is affected by the planned investment. A well-made report, on the other hand, results in a smooth acceptance of the project without the need for consultation of the investor with the proceeding body and saving the cost of correction of a defective documentation. An review of the literature done by the authors and the talks carried out with the staff making an assessment of reports of an impact on Natura 2000 sites showed the lack of common use in practise of a formalised set of criteria of evaluation of such documents. The aim of the study was to prepare a set of evaluation criteria for reports on environmental impact on Natura 2000 sites. The set was tested on already made reports and it showed their basic omissions and disparities. The set prepared can be used by an investor in the course of making a report. It can be also a useful tool for a verifying clerk while evaluating a report for its completeness and adequacy. On the basis of the prepared set of evaluation criteria, a procedure was proposed allowing an impartial verification of reports. As a result of analyses made, a procedure was worked out which is presented in the diagram concluding this paper.

The planning stage plays a key role in the success of each construction project. It also pertains to projects implementedin the Natura 2000 areas that cover ca. 18% of the total land area in the EU. Permission for the realization of such a project is issued after an analysis of its environmental impact on the Natura 2000 area. An important part of the analysis undertaken as part of a habitat assessment should be the evaluation of proposed material solutions. The research has revealed that habitat assessments in Poland do not fulfill this postulation. The decision-making process is based on the legal qualification criteria, and the fundamental importance in it has a precautionary principle. Practical realization of this principle demonstrates, however, shortcomings in its methodology. The article presents the results of two research stages. In the first stage, the documentation of 292 construction projects was examined in order to prepare the principal components of a checklist. They are correlated to the legal qualification criteria. However, they are more precise and systematic. In the second stage of the research, a survey of 47 experts was performed, and the result of the research is an innovative module of the checklist for qualification of construction projects to the habitat assessment, including questions on materials solutions. The research has proved that introduction of this proposal to the checklist may improve the quality of habitat assessments, increase their trustworthiness and ensure full exploitation of the possibilities which are given by the use of uniform research methods.

Even the best project of a wind power plant (WPP) can fail if there are not favourable legal regulations for its completion. Most of the research has dealt with identification of various obstacles to implement WPP (political, social, legal, environmental). Analyses of legal barriers (LBs) have been usually made at a high degree of generality. This paper offers a thorough overview of LBs for localization of WPPs in Poland. This is the country where restrictive regulations have blocked the possibility of implementing such projects in many areas. Unfriendly law may persuade investors to choose worse wind turbines foundation conditions. In our research we focus on a problem little dealt in scientific studies, i.e. on the localization of WPP in difficult geotechnical conditions. The article presents the analytical engineering method, which includes the mutual influence between foundation piles in carrying on the construction load on a subsoil. The paper presents the geotechnical parameters responsible for calculation outcomes, the theoretical basis of the curve analysis method of settlement of a single pile and of the calculation of piles settlement working in a group and fastened with a stiff head. It also shows the effect of pile arrangement in a foundation and a load distribution of in-dividual piles, as well as a settlement and leaning of foundation of wind power turbine towers. The method enables a more precise, safer and optimal design of a wind turbine foundation.