Prohlížení Acta Polytechnica CTU Proceedings. 2019, vol. 22 dle názvu
Zobrazují se záznamy 1-20 z 27
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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 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 ... -
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 ... -
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 ... -
EFFECTS OF ABRASIVES DURING ACCELERATED SIMULATION OF MECHANICAL CORROSION OF CEMENT COMPOSITES USING ABRASIVE WATER FLOW
(České vysoké učení technické v PrazeCzech Technical University in Prague, 2019)The paper deals with the use of the abrasive water flow technology in an accelerated simulation of the process of mechanical degradation of surface layers of cement-based composites by flowing liquids. Effects of the ... -
ELECTRICAL PROPERTIES OF FLY ASH GEOPOLYMER COMPOSITES WITH GRAPHITE CONDUCTIVE ADMIXTURES
(České vysoké učení technické v PrazeCzech Technical University in Prague, 2019)Construction materials with increased electrical conductivity could be possibly used in health monitoring of structures (stress, deformation, damages), their maintenance or traffic monitoring. The aim of this study was the ... -
EXPERIMENTAL ANALYSIS FOCUSED ON THE MATERIAL CHARACTERISTICS OF THE CEMENT-BASED POLYMER-MODIFIED MORTARS
(České vysoké učení technické v PrazeCzech Technical University in Prague, 2019)The article deals with the experimental analysis focused on the development of the physical and mechanical characteristics of the cement-based polymer-modified mortars (PCM) during ageing. Two different commercial products ... -
EXPERIMENTAL STUDIES OF ACCELERATED CHLORIDE TRANSPORT IN CONCRETE
(České vysoké učení technické v PrazeCzech Technical University in Prague, 2019)This contribution deals with the efficiency of electromigration of chlorides used as a repair method for reinforced concrete structures. Experimental studies of accelerated chloride transport tests were performed on samples ... -
EXPERIMENTAL VERIFICATION OF IMPREGNATED TEXTILE REINFORCEMENT SPLICING BY OVERLAPPING
(České vysoké učení technické v PrazeCzech Technical University in Prague, 2019)This paper presents an experimental verification of impregnated textile reinforcement splicing by overlapping using tensile test of small textile reinforced concrete slabs before its using in the product. The specimen ... -
FRESH STATE PROPERTIES OF LIME MORTARS WITH FLAX OIL ADMIXTURE
(České vysoké učení technické v PrazeCzech Technical University in Prague, 2019)Flax oil has been used as mortar improving, hydrophobic, admixture already in ancient times. The paper describes the identification of flax oil in mosaic mortar from ca. 1900 by help of FTIR spectroscopy. This historic ... -
INFLUENCE OF CORUNDUM AS COARSE AGGREGATE IN HIGH-PERFORMANCE CONCRETE ON PROJECTILE IMPACT RESISTANCE
(České vysoké učení technické v PrazeCzech Technical University in Prague, 2019)The aim of this paper is focused on the influence of corundum as coarse aggregate in high-performance concrete on projectile impact resistance in terms of depth of penetration and size of the crater. Based on the experimental ... -
LIGHTWEIGHT UHPC FACADE PANEL WITH LED DISPLAY
(České vysoké učení technické v PrazeCzech Technical University in Prague, 2019)This article deals with the development of lightweight UHPC facade panel which also can serve as an LED display. Combining both functions into one gives the potential ability to create a LED display on the facade of the ... -
MECHANICAL PROPERTIES IMPROVEMENT OF FIBER REINFORCED CONCRETE
(České vysoké učení technické v PrazeCzech Technical University in Prague, 2019)Fiber reinforced concrete mechanical properties are limited due to low adhesion between polymer fibers and cement matrix. To ensure a strong interaction between the two materials, polypropylene fibers (d = 0.305mm) were ... -
MONITORING AND PROTECTION OF TIMBER-CONCRETE BRIDGES
(České vysoké učení technické v PrazeCzech Technical University in Prague, 2019)The majority of timber bridges for ordinary road traffic are often made as timber-concrete composite structures. Concrete slab is something like as umbrella for timber. The reason for problems in timber-concrete bridges ... -
OPTIMIZATION OF MIX-DESIGN OF CHEMICALLY RESISTANT SPRAYED CONCRETE
(České vysoké učení technické v PrazeCzech Technical University in Prague, 2019)This paper addresses optimization of mix-design and granulometric curves of aggregate of chemically resistant cementitious sprayed mix. The target of the paper is to improve properties of currently developed mix-design, ... -
PHYSICAL-MECHANICAL PROPERTIES AND DURABILITY OF HYDRAULIC LIME-BASED MORTARS WITH NON-TRADITIONAL BIOPOLYMERS
(České vysoké učení technické v PrazeCzech Technical University in Prague, 2019)The study focuses on the influence of addition of four different biopolymers in various doses (0.1%, 0.5%, and 1%) on the physical-mechanical properties and durability of NHL 3.5 mortars prepared with constant water/binder ... -
RECYCLING OF CONSTRUCTION WASTE USING HIGH-SPEED MILLING PROCESS: DETERMINATION OF WASTE CONCRETE
(České vysoké učení technické v PrazeCzech Technical University in Prague, 2019)This paper deals with the use of high-speed milling process for recycling old concrete and direct determination of the potential of input waste. For this purpose, three different types of waste concrete were used: prefabricated ... -
SHORT-TERM CORROSION RESPONSE OF METALS IN LIME MORTAR
(České vysoké učení technické v PrazeCzech Technical University in Prague, 2019)Even though the corrosion of steel in concrete is very well described, the corrosion processes in lime environment studied very rarely. This environment is obviously also basic and its pH decreases in time, but the obtained ...