Self-compacting concrete with reduced formwork pressures
Self-compacting concrete (SCC) is normally characterized with high pressures exerted on the formwork during casting. The pressures can easily exceed bearing capacity of a regular formwork when casting a high structural member in one step. The contribution shows new ways of reducing the pressures us...
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| Format: | Article |
| Language: | English |
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Czech Technical University in Prague
2024-05-01
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| Series: | Acta Polytechnica CTU Proceedings |
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| Online Access: | https://ojs.cvut.cz/ojs/index.php/APP/article/view/9862 |
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| author | Jiří Němeček Pavel Trávníček Jan Tichý |
| author_facet | Jiří Němeček Pavel Trávníček Jan Tichý |
| author_sort | Jiří Němeček |
| collection | DOAJ |
| description |
Self-compacting concrete (SCC) is normally characterized with high pressures exerted on the formwork during casting. The pressures can easily exceed bearing capacity of a regular formwork when casting a high structural member in one step. The contribution shows new ways of reducing the pressures using mineral additives based on calcinated clay minerals and clay nanoparticles whose addition together with interrupted casting process leads to a substantial reduction of the formwork pressures. Short interruptions in the casting lead to microstructural changes and flocculation, thixotropy and early strength evolution. The positive effects are studied systematically in microstructural studies performed on modified cement pastes using microscopy and viscosimetry. Rheological behavior of standard SCCs is improved towards thixotropy of the mixture by using the mineral additives. The newly developed recipes are tested on SCCs used on real construction sites. Examples of their practical utilization and on-site measurements show on up to 50 % pressure reductions in enriched SCCs compared to ordinary SCCs.
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| format | Article |
| id | doaj-art-e572e866690e4369b641bbd0ddf68dde |
| institution | DOAJ |
| issn | 2336-5382 |
| language | English |
| publishDate | 2024-05-01 |
| publisher | Czech Technical University in Prague |
| record_format | Article |
| series | Acta Polytechnica CTU Proceedings |
| spelling | doaj-art-e572e866690e4369b641bbd0ddf68dde2025-08-20T03:19:07ZengCzech Technical University in PragueActa Polytechnica CTU Proceedings2336-53822024-05-014710.14311/APP.2024.47.0089Self-compacting concrete with reduced formwork pressuresJiří Němeček0Pavel Trávníček1Jan Tichý2Czech Technical University in Prague, Faculty of Civil Engineering, Thákurova 7, 166 29 Prague 6, Czech RepublicCzech Technical University in Prague, Faculty of Civil Engineering, Thákurova 7, 166 29 Prague 6, Czech RepublicSkanska a.s., Křižíkova 682/34a, 186 00 Prague 8, Czech Republic Self-compacting concrete (SCC) is normally characterized with high pressures exerted on the formwork during casting. The pressures can easily exceed bearing capacity of a regular formwork when casting a high structural member in one step. The contribution shows new ways of reducing the pressures using mineral additives based on calcinated clay minerals and clay nanoparticles whose addition together with interrupted casting process leads to a substantial reduction of the formwork pressures. Short interruptions in the casting lead to microstructural changes and flocculation, thixotropy and early strength evolution. The positive effects are studied systematically in microstructural studies performed on modified cement pastes using microscopy and viscosimetry. Rheological behavior of standard SCCs is improved towards thixotropy of the mixture by using the mineral additives. The newly developed recipes are tested on SCCs used on real construction sites. Examples of their practical utilization and on-site measurements show on up to 50 % pressure reductions in enriched SCCs compared to ordinary SCCs. https://ojs.cvut.cz/ojs/index.php/APP/article/view/9862self-compacting concretemetakaolinnanoclayformwork pressurethixotropy |
| spellingShingle | Jiří Němeček Pavel Trávníček Jan Tichý Self-compacting concrete with reduced formwork pressures Acta Polytechnica CTU Proceedings self-compacting concrete metakaolin nanoclay formwork pressure thixotropy |
| title | Self-compacting concrete with reduced formwork pressures |
| title_full | Self-compacting concrete with reduced formwork pressures |
| title_fullStr | Self-compacting concrete with reduced formwork pressures |
| title_full_unstemmed | Self-compacting concrete with reduced formwork pressures |
| title_short | Self-compacting concrete with reduced formwork pressures |
| title_sort | self compacting concrete with reduced formwork pressures |
| topic | self-compacting concrete metakaolin nanoclay formwork pressure thixotropy |
| url | https://ojs.cvut.cz/ojs/index.php/APP/article/view/9862 |
| work_keys_str_mv | AT jirinemecek selfcompactingconcretewithreducedformworkpressures AT paveltravnicek selfcompactingconcretewithreducedformworkpressures AT jantichy selfcompactingconcretewithreducedformworkpressures |