Micro- and Pore Structure Analysis of Volcanic Ash Blended Cement Paste

Volcanic ash blended cement based concrete are known for its better performance in terms of strength and durability, especially in marine environments where hot and cold climatic conditions along with chloride and sulphate attacks are detrimental for the construction materials. Since the properties of volcanic ash will vary with region to region...

Modelling the effect of electrical current flow on the hydration process of cement-based materials

Stray current is essentially an electrical current “leakage” from metal conductors and electrical installations. When it flows through cement-based systems, electrical energy is converted to thermal energy that causes increasing temperature due to Joule heating phenomena. The aim of this paper is to shed light on the influence of electrical...

Micro-hydration, pore connectivity and durability of cementitious materials

Latest developments in Hymostruc enable the possibility to evaluate the pore connectivity of an evolving microstructure while also considering the contribution of the ITZ and air voids and to examine the influence on frost durability. The numerical model is used to visualize this phenomenon and to show the contribution of both the pores and the...

Multicomponent modelling of Portland cement hydration reactions

The prospect of cement and concrete technologies depends on more in depth understanding of cement hydration reactions. Hydration reaction models simulate the development of the microstructures that can finally be used to estimate the cement based material properties that influence performance and service life. In this paper the multicomponent...

Altered cement hydration and subsequently modified porosity, permeability and compressive strength of mortar specimens due to the influence of electrical current

This paper reports on the influence of stray current flow on microstructural prop-erties, i.e. pore connectivity and permeability of mortar specimens, and link these to the observed alterations in mechanical properties and cement hydration. Mortar specimens were partly submerged in water and calcium hydroxide (Ca(OH)2) as an external environment...

Simulation of Volume Changes in Hardening Cement-Based Materials

Numerical modelling of self-desiccation of hardening cement paste

In this paper a numerical model is presented with which it is possible to predict the non-thermal hydration-induced volume changes that develop during hardening of a cement-based material. The model equilibrates the relative humidity in the pore system with the free surface energy in hardening cement past. From a certain state of equilibrium,...

Nondestructive Monitoring Hydration of Belite Calcium Sulfoaluminate Cement by EIS Measurement

In this study, the impact of water-to-cement (w/c) ratios of belite calcium sulfoaluminate cement (BCSA) on the hydration kinetics and the electrochemical impedance spectroscopy (EIS) parameters is studied. According to the analysis of classic hydration measurements, such as calorimetry tests, chemical shrinkage content, and chemically bound...

Electrical Current Flow and Cement Hydration: Implications on Cement-Based Microstructure

Stray current is an electrical current “leakage” from metal conductors and electrical installations. When it flows through cement-based materials, electrical energy is converted to thermal energy that causes increasing temperature due to Joule heating phenomena. The aim of this paper is to shed light on the influence of electrical current flow...

Investigation of the hydration properties of cement with EDTA by alternative current impedance spectroscopy

Alternative current impedance spectroscopy (ACIS) is a promising non-destructive testing method to monitor long-term change and assess the durability of concrete. This study investigates the influences of Ethylene Diamine Tetraacetic Acid (EDTA) on the hydration of hardening cement by ACIS. It is found that EDTA retards the early-age...

Cobalt immobilization performance and mechanism analysis of low carbon belite calcium sulfoaluminate cement

Cementitious materials are well acknowledged as one of the most adaptable materials for immobilizing heavy metals. Belite calcium sulfoaluminate cement (BCSA), one of the low-carbon alternative binders to cement with superior properties regarding chemical resistance and mechanical properties, is found with a desirable capability for waste...

A dissolution model of alite coupling surface topography and ions transport under different hydrodynamics conditions at microscale

Portland cement is the most produced material in the world. The hydration process of cement consists of a group of complex chemical reactions. In order to investigate the mechanism of cement hydration, it is vital to study the hydration of each phase separately. An integrated model is proposed in this paper to simulate the dissolution of...