Hydrate failure in ITZ governs concrete strength: A micro-to-macro validated engineering mechanics model

0482301 - ÚTAM 2019 RIV GB eng J - Článek v odborném periodiku
Königsberger, M. - Hlobil, Michal - Delsaute, B. - Staquet, S. - Hellmich, C. - Pichler, B.
Hydrate failure in ITZ governs concrete strength: A micro-to-macro validated engineering mechanics model.
Cement and Concrete Research. Roč. 103, č. 1 (2018), s. 77-94. ISSN 0008-8846. E-ISSN 1873-3948
Institucionální podpora: RVO:68378297
Klíčová slova: compressive strength * micromechanics * cement paste * concrete * modeling
Obor OECD: Construction engineering, Municipal and structural engineering
Impakt faktor: 5.618, rok: 2018
https://doi.org/10.1016/j.cemconres.2017.10.002

Ever since the early days of Féret (1892) and Abrams (1919), concrete research has targeted at relating concrete composition to uniaxial compressive strength. While these activities were mainly characterized by empirical fitting functions, we here take a more fundamental approach based on continuum micromechanics. The loading applied at the concrete level, is first concentrated (“downscaled”) to maximum stresses related to cement paste volumes which are directly adjacent to the aggregates, i.e. to the interfacial transition zones (ITZ). These maximum stresses are further “downscaled” to the micron-sized hydrates, in terms of higher-order stress averages. The latter enter a Drucker-Prager failure criterion with material constants derived from nanoindentation tests. The model is successfully validated across the hydrate-to-concrete scales. Strength magnitude is governed by ITZ stress concentrations, and the water-to-cement ratio is its dominant mixture design parameter.
Trvalý link: http://hdl.handle.net/11104/0277703