Zobrazeno 1 - 10
of 16
pro vyhledávání: '"Zdeněk Pertold"'
Publikováno v:
Microscopy and Microanalysis. 22:189-198
Different quartz types from several localities in the Czech Republic and Sweden were examined by polarizing microscopy combined with cathodoluminescence (CL) microscopy, spectroscopy, and petrographic image analysis, and tested by use of an accelerat
Publikováno v:
Bulletin of Engineering Geology and the Environment. 76:133-144
The alkali silica reaction (ASR), which originates in highly alkaline conditions in concrete where reactive forms of silica are available, causes serious damage to concrete structures. The ASR potential of various quartz-rich aggregates (pegmatite qu
Publikováno v:
Engineering Geology. 187:1-9
Several types of quartz-rich metamorphic rocks (medium-grained quartzite, fine-grained paragneiss, and fine-grained calc-silicate rock) all from the Těchobuz quarry (Moldanubian Zone, Bohemian Massif, Czech Republic) were investigated with the inten
Publikováno v:
Environmental Earth Sciences. 75
Rock sections mainly composed of quartz (coming from orthoquartzite, quartz metagreywacke, pegmatite quartz, vein quartz, chert, and flint) were subjected to experimental etching in 1 M NaOH solution at 80 °C. After 4 h–14 days, the rock sections
Publikováno v:
Materials Characterization. 65:115-125
characteristic of ASR in the concrete used for the pavement construction, based on cathodoluminescence and petrological image analyses
Publikováno v:
Magazine of Concrete Research. 63:553-571
Alkali–silica reaction produces deterioration of concrete, visible on the macro- and micro-scale. Macro-indicators of alkali–silica reaction are important in the field inspection of concrete. Micro-indicators help to verify the presence of alkali
Publikováno v:
Materials Characterization. 61:1379-1393
Alkali-silica gels (ASG) were investigated in concrete from bridge structures (constructed from the 1920s to 2000), as well as in experimental specimens; employing optical microscopy, petrographic image analysis, and scanning electron microscopy comb
Publikováno v:
Environmental Earth Sciences. 62:429-441
Monthly sampling of slightly alkaline arsenic-rich stream in the Mokrsko gold deposit revealed seasonal variations in dissolved Zn, Cu, As and Mo. Concentrations of trace metal cations (Zn, Cu) increased as much as 330 and 178%, respectively, from mi
Publikováno v:
Magazine of Concrete Research. 61:645-654
The alkali–silica reactivity potential of 20 different Quaternary natural aggregates (sands and gravels) from the Czech Republic has been evaluated by petrographic and dilatometric methods. Petrographic techniques, both qualitative (optical and sca
Publikováno v:
Construction and Building Materials. 23:734-741
Cracks and white coatings have been observed in a number of concrete bridges constructed during the 20th century. The observed damage phenomena have been attributed to the alkali–silica reaction (ASR) after following detailed macroscopic examinatio