Prohlížení Acta Polytechnica CTU Proceedings. 2019 ( vol. 21-25) dle názvu
Zobrazují se záznamy 1-20 z 72
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3D FEM ANALYSIS OF THE CONSTRUCTION PIT FOR A TBM-DRIVEN FLOOD DISCHARGE GALLERY
(České vysoké učení technické v PrazeCzech Technical University in Prague, 2019)As one speciality of the Swiss hydraulic engineering tradition, several torrent diversion schemes were undertaken dating from the 18th century, with the aim of using the natural lake as a retention basin. The recent project ... -
A COMPARISON OF TESTING METHODS FOR DETERMINATION OF SPRAYED CONCRETE TENSILE STRENGTH
(České vysoké učení technické v PrazeCzech Technical University in Prague, 2019)Sprayed concrete is important construction material in tunnelling. Primary lining is essential in NATM where the sprayed concrete can be loaded by tension due to bending moments. The tension is common reason of failure ... -
A HEADRACE TUNNEL RECONSTRUCTION IN TURKEY
(České vysoké učení technické v PrazeCzech Technical University in Prague, 2019)The operation of a hydro power project in North Turkey started in 2015, included the 12km long headrace tunnel. An 8km long lower tunnel section was excavated by double shield TBM technology with 8.7m ID. Due to problems ... -
A RETAINING WALL RECONSTRUCTION IN KUTNÁ HORA
(České vysoké učení technické v PrazeCzech Technical University in Prague, 2019)This paper addresses the reconstruction of a historical stone retaining wall at the busy Kremnická – Táborská road in the town of Kutná Hora. The structure was in very poor condition. There was the danger of an accident ... -
ADDITIVE MANUFACTURING PROCESS PARAMETER INFLUENCE ON MECHANICAL STRENGTH OF ADHESIVE JOINTS, PRELIMINARY ACTIVITIES
(České vysoké učení technické v PrazeCzech Technical University in Prague, 2019)The work illustrates how building parameters of the Additive Manufacturing process Fused Filament Fabrication can affect not only the mechanical properties but also the surface wettability and morphology. Wettability and ... -
ANALYSIS OF CORROSION PRODUCTS FROM WW2 CONCRETE BUNKERS IN CZECHIA
(České vysoké učení technické v PrazeCzech Technical University in Prague, 2019)The paper deals with analysis of corrosion products from historic concrete bunkers which were built in the 1930’s. Most of these objects evince numerous failures due to water penetration into the concrete structures. Two ... -
ANALYSIS OF NEUTRON FIELDS GENERATED IN SPALLATION TARGETS OF B-URAN EXPERIMENTAL ASSEMBLY USING MONTE CARLO METHOD
(České vysoké učení technické v PrazeCzech Technical University in Prague, 2019)The aim of this paper is to introduce experimental assembly B-URAN and the results of Monte Carlo simulations of neutron fields, which will be generated by using various spallation targets. This experimental assembly was ... -
ANALYSIS OF THE INFLUENCE OF TRANSDUCER FREQUENCY ON THE ULTRASONIC MEASUREMENT OF CONCRETE HOMOGENEITY
(České vysoké učení technické v PrazeCzech Technical University in Prague, 2019)The paper analyses the influence of transducer frequency on the determination of concrete homogeneity using the ultrasonic pulse velocity test. Transit time measurements were made on a 590×590mm concrete slab, with 110mm ... -
ASSESSMENT OF ADHESION BETWEEN BITUMINOUS BINDER AND MINERAL AGGREGATE USING DIGITAL IMAGE ANALYSIS
(České vysoké učení technické v PrazeCzech Technical University in Prague, 2019)Asphalt mixtures often fail due to a low adhesion of bituminous binder to mineral aggregate, which leads to surface coarse damages like potholes and fatigue cracking. To avoid this phenomenon, different types of adhesion ... -
AUTOGENOUS SHRINKAGE OF COMPOSITES BASED ON PORTLAND CEMENT
(České vysoké učení technické v PrazeCzech Technical University in Prague, 2019)Autogenous shrinkage of cement based composites is important property influencing number of their engineering application. Its ultimate value is predominantly determined by mineralogical composition of cement and its ... -
CHARACTERIZATION OF LIGHTWEIGHT LIME MORTARS CONTAINING BRICK WASTE POWDER
(České vysoké učení technické v PrazeCzech Technical University in Prague, 2019)This work deals with the effects of an expanded perlite (EP) on the hardened properties of air lime mortars with a 50% brick waste powder content. The influence of different substitution of quartz sand by EP is also monitored ... -
CHLORIDE RESISTANCE OF NANO-PARTICLE REPAIRED CONCRETE
(České vysoké učení technické v PrazeCzech Technical University in Prague, 2019)This paper describes the results of the experimentally modeled chloride ion penetration into different quality concrete structures with fully developed carbonation. Parts of concrete samples were further treated, to increase ... -
COATED CLADDING BEHAVIOR DURING HIGH-TEMPERATURE TRANSIENTS
(České vysoké učení technické v PrazeCzech Technical University in Prague, 2019)The concept of accident-tolerant fuels has been proposed and widely investigated over the past decade. The contribution is focused on one of the near-term approaches - the modification of the surface of existing Zr-alloy ... -
COMPRESSIVE PROPERTIES OF AUXETIC STRUCTURES WITH CONTROLLED STIFFNESS OF STRUT JOINTS
(České vysoké učení technické v PrazeCzech Technical University in Prague, 2019)Presented paper deals with experimental study on compressive properties of auxetics with controlled stiffness of strut joints. The variable strut joints properties were simulated by adding extra amount of material in the ... -
CUSTOM-MADE RHEOMETER FOR THE EXPERIMENTAL STUDY OF POLYURETHANE RESIN PU9010
(České vysoké učení technické v PrazeCzech Technical University in Prague, 2019)Polyurethane resins are well-known examples in aerospace industry, electronics and automotive as an adhesive or coating because of their broad spectrum of properties. They are obtained by a process called curing, where in ... -
DEBRIS-FRETTING TEST OF COATED AND UNCOATED ZR-1%NB CLADDING
(České vysoké učení technické v PrazeCzech Technical University in Prague, 2019)Debris fretting is one of the most significant fuel rod failure causes. An approach to mitigate this is to apply special coatings on the surface of the cladding that are supposed to increase the wear resistance. This paper ... -
DEFORMATION RESPONSE OF POLYDIMETHYLSILOXANE SUBSTRATES SUBJECTED TO UNIAXIAL QUASI-STATIC LOADING
(České vysoké učení technické v PrazeCzech Technical University in Prague, 2019)To investigate cellular response of cardiomyocytes to substrate mechanics, biocompatible material with stiffness in physiological range is needed. PDMS based material is used for construction of microfluidic organ on chip ... -
DIAMOND DETECTORS FOR FAST TRANSIENT SCRAM MEASUREMENTS – THE DETECTOR DEVELOPMENT
(České vysoké učení technické v PrazeCzech Technical University in Prague, 2019)This paper presents a development of special diamond detector for time dependent neutron flux measurements in a nuclear reactor. Neutron flux changes during SCRAM are difficult to measure by existing detector technologies. ... -
DIRECT MEASUREMENT OF REACTION FORCES DURING FAST DYNAMIC LOADING
(České vysoké učení technické v PrazeCzech Technical University in Prague, 2019)The presented paper is focused on embedding of the serially manufactured piezo-electric impact loadcell into Open Hopkinson Pressure Bar (OHPB) and it’s modifications for a direct force measurement during dynamic loading. ... -
DURABILITY OF CONCRETE WITH BINDER BASED ON SULFOCALCIC FLY ASH
(České vysoké učení technické v PrazeCzech Technical University in Prague, 2019)This paper deals with the durability of concrete with binder based on sulfocalcic fly ash. At the beginning, in the theoretical part, there is a research on the frost resistance of concrete, its resistance to chemical thaw ...