Two scale models for fracture behaviours of cementitious materials subjected to static and cyclic loadings

This study employs a lattice fracture model to simulate static and fatigue fracture behaviour of Interfacial Transition Zone (ITZ) at microscale and mortar at mesoscale. The heterogeneous microstructure of ITZ and mesostructure of mortar are explicitly considered in the models. The initial step involves calibrating and validating the...

Experimentally-informed lattice model to simulate the fiber pull-out behavior at the microscale

Engineered cementitious composite (ECC) is widely employed in engineering due to its high toughness and ductility. The Interfacial Transition Zone (ITZ) between the fibers and the matrix plays a vital role in influencing the strength and durability of ECC. This study introduces a numerical method to simulate fiber pull-out behaviors,...

Distribution of porosity surrounding a microfiber in cement paste

This study investigates the microstructural changes of cement paste due to the inclusion of polymeric microfiber at different water-to-cement (w/c) ratios. A procedure to quantify the porosity of epoxy impregnated interfacial transition zone (ITZ) is also presented. Results show that the microstructures of the ITZ beneath and above a...

Nanomechanical Characteristics of Interfacial Transition Zone in Nano-Engineered Concrete

This study investigates the effects of nanofillers on the interfacial transition zone (ITZ) between aggregate and cement paste by using nanoindentation and statistical nanoindentation techniques. Moreover, the underlying mechanisms are revealed through micromechanical modeling. The nanoindentation results indicate that incorporating...

Flexural strength and fatigue properties of interfacial transition zone at the microscale

In this study, the flexural strength and fatigue properties of interfacial transition zone (ITZ) were experimentally investigated at the micrometre length scale. The hardened cement paste cantilevers (150 × 150 × 750 μm³) attached to a quartzite aggregate surface were prepared and tested under the monotonic and cyclic load using a...

The effect of the steel–concrete interface on chloride-induced corrosion initiation in concrete: a critical review by RILEM TC 262-SCI

The steel–concrete interface (SCI) is known to influence corrosion of steel in concrete. However, due to the numerous factors affecting the SCI—including steel properties, concrete properties, execution, and exposure conditions—it remains unclear which factors have the most dominant impact on the susceptibility of reinforced concrete to...

Using recycle concrete aggregate coating agent for improving concrete microstructure and hardened characteristics

Recycled concrete aggregates (RCA) have been widely used as concrete aggregates in construction. This is due to economic and environmental benefits of using RCA in concrete. Unlike natural aggregate (NA), the use of RCA in concrete seems not promising to the users implementing it, especially in structural purposes. The RCA concrete is reported...

The steel–concrete interface

Although the steel–concrete interface (SCI) is widely recognized to influence the durability of reinforced concrete, a systematic overview and detailed documentation of the various aspects of the SCI are lacking. In this paper, we compiled a comprehensive list of possible local characteristics at the SCI and reviewed available information...

Systematic research on compucrete can shed light on some controversial issues in concrete technology

Realistically simulating fresh and hardening cementitious materials renders possible understanding controversial issues existing in the field of concrete technology. The experimental studies on the impact of the interfacial transition zone (ITZ) on permeability of concrete reveal two controversial results. The first involves the concept of...

The ITZ in concrete with natural and recycled aggregates: Study of microstructures based on image and SEM analysis

Aim of this work was to investigate the microstructure of the Interfacial Transition Zone (ITZ) between cement paste and aggregate in concrete utilizing Scanning Electron Microscope (SEM) in order to identify possible effects on the ITZ related to different recipes and production parameters. SEM is an important tool to carry out concrete, cement...

SPACE Approach to Concrete's Space Structure and its Mechanical Properties

Structural properties of particulate materials can be described in densities of the particle packing, more generally denoted as particle composition. Obviously, this global measure does not offer information on the way particles are mutually arranged in space. This is associated with particle configuration. This terminology and the associated...

Crack Development in Concrete due to Moisture Flow

The goal of this study is to develop a numerical model for the simulation of crack growth due to moisture flow in the porous zone between aggregate and matrix (interfacial transition zone, ITZ), where cracking in concrete originates. Two models are coupled based on similarities in their mesh shape: a Lattice Gas Automaton for moisture flow and a...