Details
| Original language | English |
|---|---|
| Article number | 170 |
| Journal | Materials and Structures/Materiaux et Constructions |
| Volume | 56 |
| Issue number | 9 |
| Early online date | 26 Oct 2023 |
| Publication status | Published - Nov 2023 |
Abstract
Creep and shrinkage are strongly influenced by the moisture content of concrete and by the ambient humidity. The effect of the latter is currently considered in models and design codes such as the fib Model Code 2010 by time-average considerations, thus totally neglecting cyclic changes in ambient humidity normally observed in outdoor structures. However, the influence of the cyclic ambient humidity on the long-term deformations of concrete compared to the constant mean humidity has barely been investigated. Therefore, the developments of creep and shrinkage of a normal-strength concrete C30/37 with three initial (before testing) moisture contents at constant humidity as well as cyclic humidity were investigated. Results demonstrate that the drying shrinkage and drying creep, but also the basic creep, are higher with higher initial moisture contents at constant ambient humidity conditions. Additionally, creep strains sharply increased up to plus 60% due to cyclic humidity compared to those due to corresponding average constant humidity. The influence of cyclic ambient humidity is more pronounced for concretes with lower initial moisture contents. Those strong deviations in the creep behaviour (compared to existing design models) may cause severe safety risks in prestressed concrete constructions. Therefore, existing creep models should be modified considering the influence of cyclic changes in humidity and the combined influence of the initial moisture content.
Keywords
- Constant humidity, Creep, Cyclic humidity, Initial moisture content, Normal-strength concrete, Shrinkage
ASJC Scopus subject areas
- Engineering(all)
- Mechanics of Materials
- Materials Science(all)
- General Materials Science
- Engineering(all)
- Building and Construction
- Engineering(all)
- Civil and Structural Engineering
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In: Materials and Structures/Materiaux et Constructions, Vol. 56, No. 9, 170, 11.2023.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Influence of initial moisture content on creep and shrinkage of concrete at constant and cyclic ambient humidity
AU - Podhajecky, Anna-Lena Denise
AU - Oneschkow, Nadja
AU - Kern, Bianca
AU - Lohaus, Ludger
AU - Müller, Harald S.
AU - Haist, Michael
N1 - Funding Information: Open Access funding enabled and organized by Projekt DEAL. This research was funded by the German Research Foundation (DFG) within the project “Creep and shrinkage at variable hygric exposures”, project number 327002599. Open Access funding enabled and organised by Projekt DEAL.
PY - 2023/11
Y1 - 2023/11
N2 - Creep and shrinkage are strongly influenced by the moisture content of concrete and by the ambient humidity. The effect of the latter is currently considered in models and design codes such as the fib Model Code 2010 by time-average considerations, thus totally neglecting cyclic changes in ambient humidity normally observed in outdoor structures. However, the influence of the cyclic ambient humidity on the long-term deformations of concrete compared to the constant mean humidity has barely been investigated. Therefore, the developments of creep and shrinkage of a normal-strength concrete C30/37 with three initial (before testing) moisture contents at constant humidity as well as cyclic humidity were investigated. Results demonstrate that the drying shrinkage and drying creep, but also the basic creep, are higher with higher initial moisture contents at constant ambient humidity conditions. Additionally, creep strains sharply increased up to plus 60% due to cyclic humidity compared to those due to corresponding average constant humidity. The influence of cyclic ambient humidity is more pronounced for concretes with lower initial moisture contents. Those strong deviations in the creep behaviour (compared to existing design models) may cause severe safety risks in prestressed concrete constructions. Therefore, existing creep models should be modified considering the influence of cyclic changes in humidity and the combined influence of the initial moisture content.
AB - Creep and shrinkage are strongly influenced by the moisture content of concrete and by the ambient humidity. The effect of the latter is currently considered in models and design codes such as the fib Model Code 2010 by time-average considerations, thus totally neglecting cyclic changes in ambient humidity normally observed in outdoor structures. However, the influence of the cyclic ambient humidity on the long-term deformations of concrete compared to the constant mean humidity has barely been investigated. Therefore, the developments of creep and shrinkage of a normal-strength concrete C30/37 with three initial (before testing) moisture contents at constant humidity as well as cyclic humidity were investigated. Results demonstrate that the drying shrinkage and drying creep, but also the basic creep, are higher with higher initial moisture contents at constant ambient humidity conditions. Additionally, creep strains sharply increased up to plus 60% due to cyclic humidity compared to those due to corresponding average constant humidity. The influence of cyclic ambient humidity is more pronounced for concretes with lower initial moisture contents. Those strong deviations in the creep behaviour (compared to existing design models) may cause severe safety risks in prestressed concrete constructions. Therefore, existing creep models should be modified considering the influence of cyclic changes in humidity and the combined influence of the initial moisture content.
KW - Constant humidity
KW - Creep
KW - Cyclic humidity
KW - Initial moisture content
KW - Normal-strength concrete
KW - Shrinkage
UR - http://www.scopus.com/inward/record.url?scp=85175034693&partnerID=8YFLogxK
U2 - 10.1617/s11527-023-02254-1
DO - 10.1617/s11527-023-02254-1
M3 - Article
VL - 56
JO - Materials and Structures/Materiaux et Constructions
JF - Materials and Structures/Materiaux et Constructions
SN - 1359-5997
IS - 9
M1 - 170
ER -