- document
-
Xu, Y. (author), Zhang, H. (author), Schlangen, E. (author), Lukovic, M. (author), Šavija, B. (author)Auxetic behavior refers to material with negative Poisson's ratio. In this research, a new type of cementitious auxetic material is developed. A novel crack bridging auxetic mechanism is discovered which is in contrast with a local buckling mechanism commonly employed to trigger auxetic behavior. Taking advantage of 3D printing techniques,...journal article 2020
- document
-
Zhang, H. (author), Xu, Y. (author), Gan, Y. (author), Chang, Z. (author), Schlangen, E. (author), Šavija, B. (author)Application of micromechanical modelling of hydrated cement paste (HCP) gains more and more interests in the field of cementitious materials. One of the most promising approaches is the use of so-called microstructure informed micromechanical models, which provides a direct link between microstructure and mechanical properties. In order to...journal article 2020
- document
-
Zhang, H. (author), Xu, Y. (author), Gan, Y. (author), Schlangen, E. (author), Šavija, B. (author)This paper presents a validation process of the developed multi-scale modelling scheme on mortar composites. Special attention was paid to make the material structure of real and virtual mortar specimens comparable at the meso-scale. The input mechanical parameters of cement paste (both bulk cement paste and interfacial transition zone) at the...journal article 2020
- document
-
Chang, Z. (author), Zhang, Hongzhi (author), Schlangen, E. (author), Šavija, B. (author)The lattice fracture model is a discrete model that can simulate the fracture process of cementitious materials. In this work, the Delft lattice fracture model is reviewed and utilized for fracture analysis. First, a systematic calibration procedure that relies on the combination of two uniaxial tensile tests is proposed to determine the input...journal article 2020
- document
-
Chen, Y. (author), Jansen, K. (author), Zhang, H. (author), Romero Rodriguez, C. (author), Gan, Y. (author), Copuroglu, Oguzhan (author), Schlangen, E. (author)For a single batch material, time intervals and nozzle standoff distances between two subsequent layers are two critical printing parameters that influence the mechanical performance of the printed concrete. This paper presents an experimental and numerical study to investigate the impacts of these printing parameters on the interlayer bond...journal article 2020
- document
-
Jiang, Nengdong (author), Zhang, Hongzhi (author), Chang, Z. (author), Schlangen, E. (author), Ge, Zhi (author), Šavija, B. (author)A combination of laboratory experiments and numerical simulations at multiple length scales can provide in-depth understanding of fracture behaviour of hydrated cement paste (HCP). To that end, the current work presents a numerical study on compressive failure of hydrated cement paste (HCP) at the micro-scale. Virtual specimens consisting of...journal article 2020
- document
-
Zhang, H. (author), Romero Rodriguez, C. (author), Dong, H. (author), Gan, Y. (author), Schlangen, E. (author), Šavija, B. (author)Carbonation of hydrated cement paste (HCP) causes numerous chemo-mechanical changes in the microstructure, e.g., porosity, strength, elastic modulus, and permeability, which have a significant influence on the durability of concrete structures. Due to its complexity, much is still not understood about the process of carbonation of HCP. The...journal article 2020
- document
-
Gan, Y. (author), Vandamme, Matthieu (author), Zhang, Hongzhi (author), Chen, Y. (author), Schlangen, E. (author), van Breugel, K. (author), Šavija, B. (author)This study proposes an experimental method for studying the short-term creep behaviour of cement paste at micro-scale. The micro-bending tests on miniaturized cantilever beams were used to characterize the viscoelastic properties of cement paste. The effects of w/b ratio, the type of binder and the stress level on the microscopic creep...journal article 2020
- document
-
Šavija, B. (author), Zhang, H. (author), Schlangen, E. (author)This work aims to understand deformation and fracture processes in blast furnace slag cement pastes made using CEM III/B which is commonly used in the Dutch infrastructure sector. First, based on our previous work on Portland cement pastes, a micromechanical model utilizing nanoindentation and X-ray computed tomography (CT) for input is...journal article 2020
- document
-
Zhang, H. (author), Šavija, B. (author), Lukovic, M. (author), Schlangen, E. (author)This work proposes a method for numerically investigating the fracture mechanism of cement paste at the microscale based on X-ray computed tomography and nanoindentation. For this purpose, greyscale level based digital microstructure was generated by X-ray microcomputed tomography with a resolution of 2 μm/voxel length. In addition,...journal article 2019
- document
-
Xu, Y. (author), Zhang, H. (author), Šavija, B. (author), Chaves Figueiredo, S. (author), Schlangen, E. (author)A method is presented to model deformation and fracture behavior of 3D printed disordered lattice materials under uniaxial tensile load. A lattice model was used to predict crack pattern and load-displacement response of the printed lattice materials. To include the influence of typical layered structures of 3D printed materials in the...journal article 2019
- document
-
Zhang, H. (author), Schlangen, E. (author), Šavija, B. (author)This work aims to investigate the mechanical properties of the cement paste-aggregate interface by combining experimental and numerical approaches. The multi-phase interface microstructure was obtained by X-ray computed tomography (XCT) and submitted to a discrete fracture lattice model for fracture analysis. Apart from the modelling, a...conference paper 2019
- document
-
Chang, Z. (author), Zhang, H. (author), Schlangen, E. (author), Šavija, B. (author)The aim of this work is to investigate the fracture process of concrete under various boundary conditions. Although numerous concrete fracture tests have been reported, showing the failure behavior of concrete, their evaluation is ambiguous due to the limitations of specimen size and experimental conditions. Therefore, it is necessary to use...conference paper 2019
- document
-
Gan, Y. (author), Zhang, H. (author), Šavija, B. (author), Schlangen, E. (author), van Breugel, K. (author)Nanoindentation is usually used to investigate local elastic properties and hardness of materials. In this paper, the nanoindenter served as a loading tool to perform micro scale bending tests and measure the global response of micro-scale specimens. For testing, cement paste cantilever beams with a square cross-section of 300 μm × 300 μm were...conference paper 2019
- document
-
Zhang, H. (author), Xu, Y. (author), Gan, Y. (author), Chang, Z. (author), Schlangen, E. (author), Šavija, B. (author)The aim of this work is to investigate the mechanical performance of hardened cement paste (HCP) under compression at the micrometre length scale. In order to achieve this, both experimental and numerical approaches were applied. In the experimental part, micrometre sized HCP specimens were fabricated and subjected to uniaxial compression by...journal article 2019
- document
-
Šavija, B. (author), Zhang, H. (author), Schlangen, E. (author)Properties of concrete are, to a large extent, dependent on the properties of its binding constituent, hydrated cement paste. Therefore, knowledge of properties of hydrated cement paste is crucial for predicting concrete behavior. This paper presents an experimentally informed approach for modeling elastic and transport properties of cement...journal article 2019
- document
-
Zhang, H. (author), Gan, Y. (author), Xu, Y. (author), Zhang, Shizhe (author), Schlangen, E. (author), Šavija, B. (author)The aim of this work is to predict the micromechanical properties of interfacial transition zone (ITZ) by combining experimental and numerical approaches. In the experimental part, hardened cement paste (HCP) cantilevers (200 μm × 100 μm × 100 μm) attached to a quartzite aggregate were fabricated and tested using micro-dicing saw and...journal article 2019
- document
-
Zhang, H. (author), Šavija, B. (author), Schlangen, E. (author)This work presents a study of stochastic fracture properties of cement paste at the micro length scale based on a combination of X-ray computed tomography (XCT) technique and discrete lattice type fracture model. Thirty virtual specimens consisting of pore, outer hydration products, inner hydration products and anhydrous cement particles were...journal article 2018
- document
-
Zhang, H. (author), Schlangen, E. (author), Šavija, B. (author)Cement paste is the glue that holds concrete together and any improvements in material performance will come from its microstructure. For better understanding and predicting its elastic properties and fracture performance, more and more studies are carried out based on micromechanics simulations. However, the predicted results can be hardly...conference paper 2018
- document
-
Zhang, H. (author), Šavija, B. (author), Schlangen, E. (author)This work proposes a new method for micromechanical simulation of cement paste based on a combination of statistical nanoindentation and XCT technique without the need for explicit identification of distinct phases. A linear relationship between the greyscale level and local Young’s modulus was assumed and verified by the two-sample Kolmogorov...conference paper 2018