Searched for: subject%3A%22microcracks%22
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Binti Md Yunus, B. (author)
Under service conditions and because of environmental and climate changes, the concrete is at risk due to crack-induced durability problems. The consequences can be even more pronounced when concrete is exposed to specifically aggressive environmental conditions. This has been portrayed by rapid deterioration of relatively young concrete...
doctoral thesis 2023
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Wang, Chuan (author), Sun, Renjuan (author), Hu, Xinlei (author), Guan, Yanhua (author), Yang, Yingzi (author), Lu, Wei (author), Tian, Jun (author), Zhang, Hongzhi (author), Ge, Zhi (author), Šavija, B. (author)
This paper presents a research on the chloride penetration behavior of engineered cementitious composites (ECC) under sustained flexural loads. Three load levels, i.e. 30 %, 60 % and 75 % of the ultimate flexural load were used. Chloride diffusion depth and concentration profile were measured 30, 60 and 150 days after the specimen was exposed...
journal article 2023
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van der Meer, F.P. (author), Kovacevic, D. (author)
A micromechanical framework for modeling failure in unidirectional (UD) thermoplastic composites under rate-dependent off-axis loading is presented, with the aim to predict and analyze transverse matrix cracking under various load conditions. The onset of global softening in the micromodel corresponds to macroscopic matrix crack initiation. The...
conference paper 2022
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Kovacevic, D. (author), Sundararajan, Bharath K. (author), van der Meer, F.P. (author)
In this paper we develop a finite deformation micromechanical framework for modeling rate-dependent failure in unidirectional composites under off-axis loading. The model performance is compared with original experiments on thermoplastic carbon/PEEK composites tested at different strain-rates and off-axis angles. To achieve quantitative...
journal article 2022
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Ullmann, Stefan (author), Lowke, Dirk (author)
The chloride migration coefficient is the most important material parameter for the service life prediction of reinforced concrete structures in exposure to chloride. For a comprehensive and precise prediction of the service life, however, further effects such as load-induced microcracks must be taken into account. Currently coupled effects like...
conference paper 2021
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Tsitova, Aliaksandra (author), Bernachy-Barbe, Fabien (author), Bary, Benoît (author), Hild, François (author)
The safety of double wall Concrete Containment Buildings (CCBs) in the French nuclear fleet primarily depends on the level of prestress applied to concrete. The delayed strains in concrete induced by creep and shrinkage cause a loss of prestress in the inner wall that may increase the risk of potential leaks in accidental conditions. The creep...
conference paper 2021
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Li, Shuguang (author), Jia, Jinsheng (author), Xu, Yaoqun (author), Zhai, Xiangjun (author), Li, Xiulin (author), Chen, Gaixin (author)
In order to evaluate the aging status of the dam concrete for a 25-years-old concrete dam, the internal concrete and surface layer of the dam were tested by elastic wave computerized tomography (CT) and spectral analysis of surface wave (SASW). Also mechanical strength and elastic wave velocity were tested for the concrete cores from the dam....
conference paper 2021
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Li, Z. (author), Lu, T. (author), Chen, Y. (author), Wu, B. (author), Ye, G. (author)
This study aims to predict the autogenous shrinkage of alkali-activated concrete (AAC) based on slag and fly ash. A variety of analytical and numerical models are available for the prediction of autogenous shrinkage of ordinary Portland cement (OPC) concrete, but these models are found to show dramatic discrepancies when applied for AAC due...
journal article 2021
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Gao, Peng (author), Chen, Yang (author), Huang, Haoliang (author), Qian, Zhiwei (author), Schlangen, E. (author), Wei, Jiangxiong (author), Yu, Qijun (author)
Non-uniform stresses, strains and microcracking of the concretes with three coarse aggregate sizes (5–10 mm, 10–16 mm, 16–20 mm) dried under 40% relative humidity (RH) for 60 days were quantified using digital image correlation and lattice fracture modelling. The influencing mechanism of coarse aggregate size on the drying-induced...
journal article 2021
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Gao, Peng (author), Chen, Yang (author), Huang, Haoliang (author), Qian, Zhiwei (author), Schlangen, E. (author), Wei, Jiangxiong (author), Yu, Qijun (author)
To assess the effect of relative humidity (RH) on drying-induced damage in concrete, the non-uniform strains and microcracks in concrete under different RH conditions were obtained using the digital image correlation (DIC) technique and lattice fracture model. The simulated non-uniform displacements were consistent with those captured using...
journal article 2020
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Bouquet, G.C. (author)
For the dimensioning of concrete structures it is customary to determine the forces and stresses occurring in construction elements on the basis of the prescribed loads. In an iterative process, the final dimensions of the elements and reinforcement are then determined. This process becomes less simple if not only the external loads, but also...
doctoral thesis 2019
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Palin, D. (author), Mo, Yu (author), Wiktor, V.A.C. (author), Jonkers, H.M. (author)
Presented is a modified test for generating crack permeability data for cementitious materials. Single-parallel cracks were generated in mortar specimens. The width of the cracks was analysed through stereomicroscope and computer tomography, and the water permeability of the cracks was determined. Reduction factors and crack flow models were...
journal article 2019
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Chen, J. (author), Liu, Xian (author), Ye, G. (author)
Microcracks play vital roles in the prediction of the service life of concrete structure. Because microcracks in concrete structure are the preferential ingression channels for aggressive ions, e.g., chloride, sulphate, etc. However, microcracks have potentials to self-heal autogenously due to the continuous hydration of unhydrated cement,...
conference paper 2016
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Sherzer, G. (author), Gao, P. (author), Ye, G. (author), Gal, E. (author)
The heterogeneity of the concrete may be considered on different size scales of observation, ranging from the atomistic scale (10-10m), characterized by the behavior of crystalline particles of hydrated Portland cement, to the macroscopic scale (101 m), where concrete has traditionally been considered homogeneous. The multiscale framework we are...
conference paper 2016
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Veer, F.A. (author), Rodichev, Y.M. (author)
We discuss “hidden damage” of glass by the rolling process, which results in heterogeneous distribution of microcracks on the edge surface of glass element, which are the fracture source deteriorating glass element strength. It is shown that removal of this damage on the edges of glass elements increases the engineering strength of float glass...
journal article 2011
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Jankovic, D. (author)
Scattered and discontinues microcracking as a subsequent side-effect of deformations due to early age drying, occurs in thin (approximately 1 mm thick) cement paste samples, when stepwise dried in ESEM. Microcracking of cement paste and restrains appear to be practically unavoidable. They are related to a phenomenon of interfaces (‘matrix’ and ...
conference paper 2009
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Jankovic, D. (author)
Novel modifications of an environmental scanning electron microscope (ESEM) were made in order to measure the local deformations in drying cement paste. These nondestructively determined moisture-induced plane strains, obtained in 1 mm thick cement paste samples, are orthotropic. They vary with variations of relative humidity between 70%-80% and...
conference paper 2008
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Jankovic, D. (author)
Defining the 'real' shrinkage values of concrete is still a subject of much debate. In shrinkage experiments size effects are inherently present. Through an attempt to determine the real shrinkage of cement-based materials, these size effects have to be eliminated or at least reduced as much a possible. In this contribution drying shrinkage...
conference paper 2007
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Bisschop, J. (author)
doctoral thesis 2002
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Bisschop, J. (author), Van Mier, J.C.M. (author)
In this paper a method is described to quantify shrinkage microcracking in young mortar by means of crack mapping. Visualisation of the microcracks is realised with two techniques: Fluorescence Light Microscopy (FLM) and Environmental Scanning Electron Microscopy (ESEM). The preliminary results obtained with the microcrack mapping method showed...
journal article 1999
Searched for: subject%3A%22microcracks%22
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