Accelerated carbonation of ordinary Portland cement paste and its effects on microstructure and transport properties

Coupling of carbonation and chlorides ingress mechanisms is very common in concrete under certain exposure conditions such as coastal environments. The aggravation/ mitigation of corrosion by the existence of carbonation lies on the fact that microstructural changes due to carbonation result in changes on the transport properties of the material...

Accelerated carbonation of ordinary Portland cement paste and its effects on microstructure and transport properties

Coupling of carbonation and chlorides ingress mechanisms is very common in concrete under certain exposure conditions such as coastal environments. The aggravation/ mitigation of corrosion by the existence of carbonation lies on the fact that microstructural changes due to carbonation result in changes on the transport properties of the material...

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...

Multi-scale modelling of the mechanics of concrete based on the cement paste properties

The mechanical response of concrete is complex and as other composite materials, multiscale modelling has the potential for modeling its macroscopic behavior. This paper presents an upscaling methodology for the model-ling of the concrete mechanical properties. The suggested formulation starts from a known chemical and mechanical set of...

Microstructure-based 3D modelling of diffusivity in sound and cracked cement paste

Exposing reinforced concrete (RC) structures to aggressive environmental conditions is one of the main reasons that may limit their service life. Diffusion of chloride ions through concrete cover is one of the most damaging environmental actions, since it may cause corrosion of steel reinforcement. Therefore, modelling this phenomenon allows...

Using nano-indentation and microscopy to obtain mechanical properties

Simulation of mechanical behaviour of heterogeneous materials is only possible if the local properties of the components are known. In recent years nano-indentation is being applied on different levels to obtain local mechanical properties. The aim of this paper is to explore various ways to obtain these properties by combining nano-indentation...

A modelling study of drying shrinkage damage in concrete repair systems

Differential shrinkage between repair material and concrete substrate is considered to be the main cause of premature failure of repair systems (Martinola, Sadouki et al. 2001, Beushausen and Alexander 2007). Magnitude of induced stresses depends on many factors, for example the amount of restraint, moisture gradients caused by different curing...

Impact of surface roughness on the debonding mechanism in concrete repairs

Surface roughness of the existing concrete substrate was considered to have the greatest impact on the bond strength in repair systems. However, the influence of this parameter has been subject for debates in recent years. The effect of concrete surface roughness is not quite clear, nor there exist a clear relation between the surface roughness...

Multiscale lattice fracture model for cement-based materials

Cracking in cement-based materials is usually not easy to predict, because of the complexity of their microstructures. Concrete is a composite material of mortar and coarse aggregates, and mortar consists of cement paste and sands. The fracture processes in these materials are related, and this paper aims to reveal the relationship by developing...

Modeling fracture behavior of cement paste based on its microstructure

Concrete is a composite construction material, which is composed primarily of coarse aggregates, sands and cement paste. The fracture processes in concrete are complicated, because of the multiscale and multiphase nature of the material. In the past decades, comprehensive effort has been put to study the cracks evolution in concrete, both...

Influences of mineral composition of cement on the mechanical properties of cement paste

Multiscale modeling scheme for cementitious materials

3D Simulation of micromechanical behavior of cement paste

Numerical modeling of fracture processes of brittle materials, such as cement paste, mortar, concrete and rocks, started in the late 1960s when the discrete and smeared cracking models were introduced. In the 1990s, Schlangen and van Mier proposed another numerical model to compensate the drawbacks of the discrete and smeared cracking models,...