Waterproof lime dust used in coal mines is an important element in the system of protection against explosions. This is one of the oldest methods used to prevent coal dust explosions and, according to an expert’s opinion, it will remain so for a long time. T he work is a summary of research on the development of a new method of producing waterproof limestone dust to use it as an anti-explosive powder in coal mines. The typical method of hydrophobic dust production (milling limestone with stearic acid) is no longer profitable due to the restructuring of the mining industry. The main research was conducted on raw materials traditionally used during the production of anti-explosion powder, namely limestone meal with a grain size diameter equal to 80 μm (Czatkowice Limestone Quarry) and stearic acid as a modifier. Silicone preparation and bituminous preparation (Bitumenovoranstrich) were used as additional modifiers. The hydrophobization process was conducted with the use of different techniques: from stearic acid ether solution, from stearic acid vapor, from methyl silicone resin or bituminous preparation solutions. A series of research on modified powders to determine hydrophobization and flow properties was conducted. Depending on method of hydrophobization, the test of “floating on water”, the extraction of stearic acid was carried out, water contact angles on compacted material were determined, the thermal decomposition of powder was made. The increase in moisture after wet storage was indicated. The flow properties of powders were measured with the use of the Powder Characteristics Tester. The evaluation of the suitability of each hydrophobization methods in achieving the intended purpose was valued.

Formation of cities was always dependent on water. Location over the water areas gave the opportunity for develop-ment and increase of prosperity. And although water was also a threat and cause of damage, the benefits of its neighbour-hood prevailed. Today, the challenge for developing cities is a climate change observed in recent decades, which results in violent natural phenomena, e.g. floods and hurricanes. One of the main problems faced by residents of housing estates lo-cated on the water is the increasing risk of flooding. Actions are taken to adapt the functioning of the urban structure and buildings to new water conditions. Currently, the process of floodplain development is progressing on a larger scale. This phenomenon is intensifying and as a result many housing estates are created in areas exposed to flooding. The approach to flood issues in the context of architecture and spatial planning has evolved in recent decades. The new water paradigm is expressed in striving to keep it in place.

How did the settlement in the floodplains look once and today in Warsaw? The research study was preceded by a his-torical feature and then the article drew attention to the ways of shaping new housing estates in flood areas in Warsaw. Us-ing the case study method, new housing estates developed in the flood plains have been analysed, with a listing of their strengths and weaknesses and the assessment of solutions. Issues were discussed on how to protect the buildings from the harmful effects of water. On the basis of the conclusions from the Warsaw case study, project guidelines for floodplains in Warsaw were developed, the aim of which was to identify the most important priorities in the development of floodplains and increase the security of investment arising in these areas.

The article presents the results of the research on thermal actions on the materials occurring in the cross section along the depth of the bridge deck and bituminous pavement during its construction. The impulse to curried out the research was the need to explain the causes of the blistering of bituminous waterproofing membranes and asphalt pavements often observed on the bridge decks. The paper presents the examples of such failures and the analyses of possible mechanisms of the phenomenon. Research indicates a significant influence of all technological processes on the temperature of materials in the cross section as well as daily temperature changes. The probability of initiation of reactions between concrete components with gaseous products has been confirmed in such conditions. The susceptibility of bituminous materials to gas emission and blistering is the subject of a separate study. The research was part of a research project carried out under the contract INNOTECHK3/IN3/50/229332/NCBR /14 [13].

In contrast to the western part of the Lower Silesia, information about the basalt-derived weathering crusts occurring in the Opole region is rather limited. However, in 2018, significant volumes of such regolith (about 20,000 m3) were discovered during development works in the NW part of the Rutki Quarry near Niemodlin. This weathering crust is rich in clay minerals and represents a smectite- kaolinite mixture with some halloysite, the latter being a poorly ordered member of the kaolinite group. The minerals of the smectite group contain in their interlayer spaces bivalent cations (calcium and magnesium), which is the most often case in the nature. The mineral composition of the regolith mass is supplemented by iron-containing phases, i.e. goethite and magnetite, and traces of phosphate mineral – crandallite. A significant amount of clay minerals, particularly those belonging to the smectite group and halloysite, results in high value of the specific surface area (up to 100 m2/g) of the studied crust. Such favorable property of the crust makes it a promising sorptive raw material that can be applied, even in an unprocessed form, for waterproofing. It must be emphasized that the sorption properties of basalt weathering crusts were noticed some centuries ago in the western part of Lower Silesia, where medicine called terra sigillata was produced from them. Moreover, the crust from Rutki was also used in the XIXth century, in a ceramic manufacture located in nearby Tułowice, where the so-called “Silesian black porcelain” was produced.