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...

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...

Multi-scale Approach from Atomistic to Macro for Simulation of the Elastic Properties of Cement Paste

In this study, first of all, the atomistic structure of cement hydration products is estimated via molecular dynamics method and their elastic properties are extracted. Then, cement hydration simulation is done by HYMOSTRUC3D model and the obtained results from both molecular dynamics and HYMOSTRUC3D methods are used for simulation in macro...

Evaluating compressive mechanical LDPM parameters based on an upscaled multiscale approach

We propose an upscaled methodology for evaluating the compressive parameters of the Lattice Discrete Particle Model (LDPM) for a multiscale analysis of concrete structures. This methodology is based on mechanical and chemical models on a wide range of concrete scales. We show that the compressive mechanical parameters are related mainly to...

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...

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...

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 novel lattice model to predict chloride diffusion coefficient of unsaturated cementitious materials based on multi-typed pore structure characteristics

This paper develops a novel lattice diffusive model to quantitatively study the chloride diffusion coefficient in unsaturated cementitious materials, in which the pore voxels are redistributed to make a better representation of a real microstructure of hardened cement paste. Considering the hierarchical microstructure and different drying...

Ultra-thin Strain Hardening Cementitious Composite (SHCC) layer in reinforced concrete cover zone for crack width control

In the current study, experiments and numerical simulations were carried out to investigate the cracking behavior of reinforced concrete beams consisting of a very thin layer (i.e., 1 cm in thickness) of SHCC in the concrete cover, tension zone. A novel type of SHCC/concrete interface that features a weakened chemical adhesion but an enhanced...

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...

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...