Engineering Commons^™

Freeze-Thaw Resistance Of Concrete: Insight From Microstructural Properties, Sam Adu-Amankwah, Leon Black Dr, M Zajac, J Skoceck, M Ben Haha

International Conference on Durability of Concrete Structures

Composite cements offer low carbon alternatives to conventional CEM I. These binders also generally tend to perform better than CEM I in aggressive chemical environments. However, their freeze-thaw resistance, evident through surface scaling and internal damage is usually impaired. Postulated theories on freeze-thaw induced damage do not fully explain the origin of this weakness in composite cement concretes.

This paper systematically presents the phase assemblage changes associated with the freeze-thaw of concrete specimen made from composite cements with and without limestone. The freeze-thaw test was performed on concrete according to CIF method based on CEN/TR 15177 and the corresponding cement …

Numerical Simulation Of The Early Age Three-Dimensional Microstructure Development Of Cement Pastes, Yunsheng Zhang, Zhiyong Liu, Wei Sun

International Conference on Durability of Concrete Structures

The formation process of microstructure in cement pastes was first simulated with a numerical model CEMHYD3D. The influence of water-to-cement ratio and particles size on heat release and degree of hydration were then investigated. In addition, the mass of CH and C–S–H phases simulated have been verified by measuring values by thermogravimetry–differential scanning calorimetry (TG-DSC) and X-ray diffraction (XRD)-Rietveld analysis. The evolutions of solids phase percolation and capillary pores de-percolation were also identified by means of a three-dimensional (3D) numerical model. The results show that the simulated values are in good agreement with the available experimental data, indicating a good …

Strength And Durability Of Concrete: Effects Of Cement Paste-Aggregate Interfaces, Part Ii: Significance Of Transition Zones On Physical And Mechanical Properties Of Portland Cement Mortar, Turng-Fang F. Lee, Menashi D. Cohen

JTRP Technical Reports

This research was based on a two-part basic research investigation studying the effects of cement paste-aggregate interfaces (or interfacial transition zones-HZ) on strength and durability of concrete. Part I dealt with the theoretical study and Part II dealt with the experimental. Part I, the theoretical part, illustrates the effect of ITZ on the concrete properties by assuming its elastic moduli to be varied continuously in the region. A four-phase composite model is employed and three functions are chosen to model the moduli variation in the ITZ. A theoretical solution for an n-layered spherical inclusion model is used to estimate the …

Strength And Durability Of Concrete: Effects Of Cement Paste-Aggregate Interfaces, Part I: Theoretical Study On Influence Of Interfacial Transition Zone On Properties Of Concrete Materials, Yiguo Zhang, Wai-Fah Chen

JTRP Technical Reports

This research was based on a two-part basic research investigation studying the effects of cement paste-aggregate interfaces (or interfacial transition zones-HZ) on strength and durability of concrete. Part I dealt with the theoretical study and Part II dealt with the experimental. Part I, the theoretical part, illustrates the effect of ITZ on the concrete properties by assuming its elastic moduli to be varied continuously in the region. A four-phase composite model is employed and three functions are chosen to model the moduli variation in the ITZ. A theoretical solution for an n-layered spherical inclusion model is used to estimate the …