TY - JOUR

T1 - Influence of Moisture Content and Wet Environment on the Fatigue Behaviour of High-Strength Concrete

AU - Ali, Mohamed Abubakar

AU - Tomann, Christoph

AU - Aldakheel, Fadi

AU - Mahlbacher, Markus

AU - Noii, Nima

AU - Oneschkow, Nadja

AU - Drake, Karl Heinz

AU - Lohaus, Ludger

AU - Wriggers, Peter

AU - Haist, Michael

N1 - Funding Information: Funding: This research was funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation)—Project numbers (353757395) (HA 7917/7-2 | LO 751/22-2 | WR 19/58-2) within the Priority Programme 2020 ‘Cyclic Deterioration of High-Performance Concrete in an Experimental-Virtual Lab’. Parts of the experimental investigation were funded by the Federal Ministry for Economic Affairs and Climate Action within the project WinConFat—Project number (0324016A). Funding Information: Acknowledgments: The authors thank the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) and the Federal Ministry of Economic Affairs and Energy for funding the research projects.

PY - 2022/1/28

Y1 - 2022/1/28

N2 - The influence of a wet environment on the fatigue behaviour of high-strength concrete has become more important in recent years with the expansion of offshore wind energy systems. According to the few investigations documented in the literature, the fatigue resistance of specimens submerged in water is significantly lower compared to that of specimens in dry conditions. However, it is still not clear how the wet environment and the moisture content in concrete influence its fatigue behaviour and which damage mechanisms are involved in the deterioration process. Here the results of a joint project are reported, in which the impact of moisture content in concrete on fatigue deterioration are investigated experimentally and numerically. Aside from the number of cycles to failure, the development of stiffness and acoustic emission (AE) hits are analysed as damage inductors and discussed along with results of microstructural investigations to provide insights into the degradation mechanisms. Subsequently, an efficient numeric modelling approach to water-induced fatigue damage is presented. The results of the fatigue tests show an accelerated degradation behaviour with increasing moisture content of the concrete. Further, it was found that the AE hits of specimens submerged in water occur exclusively close to the minimum stress level in contrast to specimens subjected to dry conditions, which means that additional damage mechanisms are acting with increasing moisture content in the concrete.

AB - The influence of a wet environment on the fatigue behaviour of high-strength concrete has become more important in recent years with the expansion of offshore wind energy systems. According to the few investigations documented in the literature, the fatigue resistance of specimens submerged in water is significantly lower compared to that of specimens in dry conditions. However, it is still not clear how the wet environment and the moisture content in concrete influence its fatigue behaviour and which damage mechanisms are involved in the deterioration process. Here the results of a joint project are reported, in which the impact of moisture content in concrete on fatigue deterioration are investigated experimentally and numerically. Aside from the number of cycles to failure, the development of stiffness and acoustic emission (AE) hits are analysed as damage inductors and discussed along with results of microstructural investigations to provide insights into the degradation mechanisms. Subsequently, an efficient numeric modelling approach to water-induced fatigue damage is presented. The results of the fatigue tests show an accelerated degradation behaviour with increasing moisture content of the concrete. Further, it was found that the AE hits of specimens submerged in water occur exclusively close to the minimum stress level in contrast to specimens subjected to dry conditions, which means that additional damage mechanisms are acting with increasing moisture content in the concrete.

KW - Acoustic emissions analysis

KW - Fatigue deterioration

KW - High-strength concrete

KW - Microscopic material model

KW - Moisture content

KW - Phase-field approach

KW - Porous media theory

KW - Water-induced degradation mechanisms

UR - http://www.scopus.com/inward/record.url?scp=85123453932&partnerID=8YFLogxK

U2 - 10.3390/ma15031025

DO - 10.3390/ma15031025

M3 - Article

AN - SCOPUS:85123453932

VL - 15

JO - MATERIALS

JF - MATERIALS

SN - 1996-1944

IS - 3

M1 - 1025

ER -