Effects of Water Jet on Heat-Affected Concretes

0392345 - ÚGN 2014 RIV NL eng J - Journal Article
Sitek, Libor - Bodnárová, L. - Válek, J. - Zeleňák, Michal - Klich, Jiří - Foldyna, Josef - Novotný, M.
Effects of Water Jet on Heat-Affected Concretes.
Procedia Engineering. Roč. 57, č. 1 (2013), s. 1036-1044. E-ISSN 1877-7058
R&D Projects: GA MŠMT ED2.1.00/03.0082
Grant - others:GA ČR(CZ) GAP104/12/1988; TA ČR(CZ) TA01010948
Program: GA
Institutional support: RVO:68145535
Keywords : concrete * heating * repair of structures * fireproof concretes * surface layers
Subject RIV: JN - Civil Engineering
http://www.sciencedirect.com/science/article/pii/S1877705813008643

The paper is dealing with the effects of flat high-speed water jet on concretes affected by high temperature. Research should help to correct use of water jet technology in repair works on concrete structures especially after wildfires in tunnels, underground garages, etc., which are exposed to enormous thermal stress. Four concrete mixtures were prepared for tests of interaction of water jet with concrete. The samples were exposed to 200 °C and 600 °C and for comparison one third of samples were left unaffected. It was found, that both lower traversing velocity (cutting speed) and higher water pressure led to removal of higher amount of concrete. Higher temperature loading caused decrease of concrete strength and thus easier removal of surface layers by water jet. Concrete mixtures with basalt aggregate demonstrate higher resistance against water jet penetration regardless thermal loading compared to mixture with standard granodiorite aggregate. Presence of polypropylene fibres has substantial influence on concrete strength properties, however only marginal impact on resistance against water jet penetration.
Permanent Link: http://hdl.handle.net/11104/0221243