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1

A study on fibre-reinforced concrete elements properties based on the case of habitat modules in the underwater sills

Kurpińska Marzena, Grzyl Beata, Kristowski Adam

Polish Maritime Research

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2020

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nr 1

143--151

EN

Hydrotechnical constructions are mostly objects functioning in extreme conditions and requiring a custom-made construction project. In the case of using prefabricated elements, it is required to develop production, transport, assembly, conservation and repair technology. Concerning the problem of concrete cracks, modern repair systems allow positive effects to be achieved in many cases of concrete elements repair. In this work an attempt has been made to assess the properties of concrete, situated in the Baltic Sea environment, in which traditional rebar was partly replaced by dispersed fibre-phase. Fibre-reinforced concrete belongs to the group of composite materials. The presence of fibres helps to increase the tensile strength, flexural strength and resilience and also prevents the appearance of cracks. In the given paper we will also discuss basic parameters of steel and polymer fibres and the influence of both types of fibres on the maturing and hardened concrete. In this work special attention has been paid to the advantages of polypropylene and polymer fibres with regard to commonly-known steel fibres. The use of synthetic fibres will be advantageous in constructions where the reduction of shrinkage cracks and high resilience are essential. On top of that, the use of synthetic fibres is highly recommended when constructing objects that will be exposed to the impact of an aggressive environment. Undoubtedly, polymer fibres are resistant to the majority of corrosive environments. Fibre-reinforced concretes are a frequently implemented construction solution. The possibility of concrete modification allows the emergence of new construction materials with improved physical-mechanical properties, under the condition of being applied relevantly.

2

The analysis of factors influencing the dynamics of lowland riverbed erosion downstream of the Jeziorsko reservoir dam (central Poland)

Smaga A., Wierzbicki J., Wierzbicki M., Hämmerling M., Radaszewski R.

Geological Quarterly

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2017

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Vol. 61, No. 4

926--933

EN

Increased riverbed erosion could recently be observed in close vicinity of hydrotechnical constructions in many lowland rivers. The immediate effect of erosion in this case is a very significant reduction of the riverbed level over a considerable distance, downstream of large reservoir dams. This process is influenced simultaneously by both hydraulics of river flow and geotechnical properties of soil eroded. The paper presents an analysis of parametric changes in the level of river bottom and grain size of bed material, and the relative density in the context of changes in hydrological conditions and diversity of engineering-geological conditions. As the result, a multiparametric model of erosional potential of riverbed sediments has been proposed, which can significantly help in proper planning of locations and construction of correction thresholds under given hydraulic conditions of the river.

3

Wykorzystanie metod geoinformacyjnych w badaniach morfodynamiki koryta Wisły w Warszawie

Falkowski T., Ostrowski P.

Przegląd Geologiczny

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2015

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Vol. 63, nr 3

186–-194

EN

Prerequisite for rational river valleys management is estimation of its evolution processes causes and directions. Such analysis requires from geologist great number of different information, acquisition of which is very often associated with difficulties resulting (for instance) from channel zone inaccessibility. Besides accuracy in location of the observation points such works require also ability in registration of environment changes during short observation periods (e.g. on the base of subsequent measurement campaigns results) as well as during long periods (e.g. comparison of the topographic or remote sensing archival data ). The perfect tool for such purposes, which is capable to integrating various research results are geographic information systems. In the regulated, downtown section of the Warsaw Vistula channel since the 60s of the last century to the early XXI century was recorded a steady decline in the level of the medium and low water flow. This process became a threat for the channel zone infrastructure. At the same time above and below this channel section, in the zone less equipped with the hydro-technical structures the process of aggradation was observed. This leads to increase of flood risk. The paper presents results of investigations, which were conducted in the Vistula River channel zone in Warsaw. During the research it was found that the reason for a particular channel environment behaviour in reaction on the management is the channel geology. In the narrow, regulated downtown channel section the contemporary alluvia substrate (built up with erosion resistant deposits) creates morphologically diverse protrusion. Upstream and downstream of that channel section the roof of alluvia substratum lowers. Lack of possibilities to deepening channel during the high waters passage in downtown narrowed channel reach affects the higher flow speeds and creates conditions of sediment transit . Shallow position of erosion resistant deposits floor affects also the thalweg course. Beyond the culmination of substratum Vistula represents the wild river, overloaded by alluvia.

4

Budowle i urządzenia hydrotechniczne w systemie obrony Kamieńca Podolskiego

Opyrchał L.

Gospodarka Wodna

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2014

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Nr 3

103--111

PL

Kamieniec Podolski stanowil najsilniejszą twierdzę kresową Rzeczypospolitej. Jest jednak faktem mało znanym, że o jego obronnym charakterze decydowały budowle piętrzące wodę. W wypadku zagrożenia atakiem piętrzono wodę i zalewano dolinę, co czyniło, że twierdza była nie do zdobycia. Artkykuł omawia hydrotechniczne budowle obronne oraz ich pozostałości.

EN

Kamieniec Podolski was the strongest borderland fortress of the Republic. However, the public does not know that it owed its defensive character to waterdamming constructions. In the event of an attack threat, water was dammed and the vаllеу flooded, what made the fortress unconquerable. The article presents the hydro-technical defensive constructions and their remnents.

5

Oddziaływanie wybranych budowli hydrotechnicznych na drożność i jakość wód rzeki Krąpiel

Brzeziński R., Bonisławska M.

Gospodarka Wodna

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2010

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Nr 1

34-43

PL

W artykule poruszono problem drożności rzek na przykładzie rzeki Krąpiel. Analiza wartości stężeń wybranych wskaźników jakości wód badanej rzeki (wykonywana przez okres siedmiu miesięcy) na wyznaczonych odcinkach, znajdujących się powyżej oraz poniżej wybranych budowli piętrzących wodę, i porównanie z wymogami zawartymi w rozporządzeniu ministra środowiska z 4 października 2002 r. „W sprawie wymagań, jakim powinny odpowiadać wody śródlądowe będące środowiskiem życia ryb w warunkach naturalnych", pozwoliły na dokonanie oceny oddziaływania budowli hydrotechnicznych na jakość wód na wybranych odcinkach rzeki Krąpiel.

EN

The article concentrates on the issue of trivers perviousness on the example of the Krąpiel River. The analysis of concentrations of chosen water quality indicators values for the examined river (performed for the period of seven months) in sections upstream and downstream from chosen damming-up constructions and comparision with requirements contained in the ordinance of the Minister of Environment of 4 October 2002 „On requirements applying to all inland waters being the habitat of fish in natural conditions" allowed to carry out evaluation of the influence of hydro-technical constructions on the water quality in chosen sections of the Krąpiel River.

6

Naprawy piętrzących budowli hydrotechnicznych przy użyciu betonu natryskowego

Kańka S., Knapik A.

Ochrona przed Korozją

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2008

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nr 5s/A

99-104

PL

W referacie przedstawiono spostrzeżenia, jakie autorzy poczynili w czasie wykonywania remontów zapory, jazu oraz śluzy, w trakcie których stosowano beton natryskowy. Opisano przygotowanie i kontrolę podłoża do nakładania betonu natryskowego. Przedstawiono modele technologiczne połączenia starego betonu z nowym w warunkach pracującej, w trakcie remontu, piętrzącej budowli hydrotechnicznej. W końcowej części referatu podano uwagi dotyczące betonu natryskowego w tego typu obiektach w świetle normy PN-EN 14487:2007"Beton natryskowy" oraz norm z nią związanych.

EN

The paper deals with some observations, which authors made during repair of dam, weir and tide gate using sprayed concrete. Preparation of substrate and its control for placing the sprayed concrete was described. Technological models of combining old concrete with new one under working conditions and repair of the watertight structure were presented. Some statements concerning sprayed concrete requirements in such buildings in the light of PN-EN 14487:2007 "Sprayed concrete " standard and other standards connected with it were given.