Size effect on compressive strength of foamed concrete: Experimental and numerical studies

This study investigates the size effect on the compressive strength of foamed concrete at the mesoscale level combining X-ray computed tomography (X-CT) and a discrete lattice model. Image segmentation techniques and X-CT were employed to obtain virtual specimens comprising hydrated cement paste and air voids. The lineal-path function and...

Lattice modelling of early-age creep of 3D printed segments with the consideration of stress history

We propose a new numerical method to analyze the early-age creep of 3D printed segments with the consideration of stress history. The integral creep strain evaluation formula is first expressed in a summation form using superposition principle. The experimentally derived creep compliance surface is then employed to calculate the creep strain...

Does early age creep influence buildability of 3D printed concrete? Insights from numerical simulations

Cementitious materials may exhibit significant creep at very early age. This is potentially important for concrete 3D printing, where the material is progressively loaded even before it sets. However, does creep actually affect the buildability of 3D printed concrete? Herein, the influence of early-age creep on the buildability of 3D printed...

Modelling of capillary water absorption in sound and cracked concrete using a dual-lattice approach: Computational aspects

Lattice models have been used to simulate mass transport to predict durability of cementitious materials. In particular, the use of dual lattice meshes allows for the coupling of fracture and transport processes, which commonly occur at the same time in these materials. Literature has shown good agreement between simulations and experimental...

Towards understanding deformation and fracture in cementitious lattice materials: Insights from multiscale experiments and simulations

Tailoring lattice structures is a commonly used method to develop lattice materials with desired mechanical properties. However, for cementitious lattice materials, besides the macroscopic lattice structure, the multi-phase microstructure of cement paste may have substantial impact on the mechanical responses. Therefore, this work proposes a...

A numerical study of fatigue of hardened cement paste at the microscale

In this study, a numerical model using a 2D lattice network is developed to investigate the fatigue behaviour of cement paste at the microscale. Images of 2D microstructures of cement pastes obtained from XCT tests are used as inputs and mapped to the lattice model. Different local mechanical and fatigue properties are assigned to different...

Micromechanical testing and modelling of blast furnace slag cement pastes

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...

Chemo-physico-mechanical properties of the interface zone between bacterial PLA self-healing capsules and cement paste

In this study, the interface between different types of bacteria-embedded self-healing polylactic acid capsules (PLA) and cement paste is investigated. Particularly, the changes in microstructure and mechanical properties of the interface with respect to bulk cement paste were studied. First, nanoindentation was performed to obtain maps of...

Deformation and fracture of 3D printed disordered lattice materials: Experiments and modeling

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...

Assessing Hydrated Cement Paste Properties Using Experimentally Informed Discrete Models

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...

Numerical investigation of crack self-sealing in cement-based composites with superabsorbent polymers

Recently the concept of crack self-sealing has been investigated as a method to prevent degradation and/or loss of functionality of cracked concrete elements. To obtain self-sealing effect in the crack, water swelling admixtures such as superabsorbent polymers (SAP) are added into the cementitious mix. In order to design such self-sealing...