Discrete lattice fracture modelling of hydrated cement paste under uniaxial compression at micro-scale. (10th December 2020)

• Record Type: Journal Article
• Authors: Jiang, Nengdong; Zhang, Hongzhi; Chang, Ze; Schlangen, Erik; Ge, Zhi; Šavija, Branko
• Is Part Of: Construction & building materials. Volume 263(2021)
• Publication Date: 2020-12-10
• Subjects: Hydrated cement paste -- Micro-scale -- Micromechanical properties -- Discrete lattice model -- Compressive behaviour; Building materials -- Periodicals; 624.18
• DOI: 10.1016/j.conbuildmat.2020.120153
• Languages: English
• ISSNs: 0950-0618

Abstract

Highlights: Compressive failure of hydrated cement paste at the micro-scale was simulated. Failure behaviour of various specimens were investigated. Boundary restraint effect is more significant for specimens with a low slenderness. The boundary condition has negligible effect on the Young's modulus. Abstract: 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 various phases were obtained using a combination of X-ray computed tomography and image segmentation techniques. The discrete lattice fracture model was used for the deformation and fracture analysis of the specimens subjected to uniaxial compression. The input local mechanical properties of each individual phase were taken from the literature in which a micro-scale compression test was conducted for the calibration of the same type model. The influence of slenderness ratios (1 and 2), water-to-cement ratios (0.3, 0.4 and 0.5 respectively) and lateral confinement of the specimen ends (free and restricted) on the failure behaviour were investigated. It has been shown by the current study that the stress–strain response cannot be completely separated from the used boundary conditions. The proposed model provides an effective tool to understand the compressive fracture behaviour of cement paste at the micro-scale.