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...

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...

Assessing properties of hydrating cement paste using X-ray computed tomography characterization

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 behaviour. This paper presents an experimentally informed approach for modelling elastic and transport properties of cement...

Assessing properties of hydrating cement paste using X-ray computed tomography characterization

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 behaviour. This paper presents an experimentally informed approach for modelling elastic and transport properties of cement...

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...

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...

Extended Lattice Model to Simulate the Printing Process of 3D Printed Cementitious Materials

This paper reports an extended lattice model for printing process simulation of 3D printed cementitious materials. In this model, several influencing factors such as material and geometric nonlinearity are considered. Using this model, green strength of cementitious material is investigated, deformation and crack pattern can be derived, which...

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...

Strain-Hardening Cementitious Composite (SHCC) For Durable Concrete Repair

Infrastructure is ageing and we are facing a serious challenge on how to deal with it. One possible solution is to repair it, but the life of current concrete repairs, including all types of repairs and application of different materials, is not satisfactory and there is an urgent need for improvement. Understanding the damage development in a...

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...

On the Potential of Lattice Type Model for Predicting Shear Capacity of Reinforced Concrete and SHCC Structures

Different analytical models exist to predict the shear strength of reinforced concrete members. Generally, each of these shear strength models consists of a formulation based on certain underlying theory and fitted model coefficients. The model fitting parameters are usually established from the comparison with test data. Hence, the predictive...