【摘 要】
：
Due to the complexity ofcontructing non-spherical particle and their packing algorithm, the influence of particle shape on interracial transition zone (ITZ) microstructure and macro-properties of ceme
【机 构】
：
Jiangsu Key Laboratory of Construction Materials, School of Materials Science & Engineering, Southea
【出 处】
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The 14th International Congress on the Chemistry of Cement (
论文部分内容阅读
Due to the complexity ofcontructing non-spherical particle and their packing algorithm, the influence of particle shape on interracial transition zone (ITZ) microstructure and macro-properties of cementitious composites is seldom discussed in the literature.In this paper, ITZ layer is successfully constructed around Platonic particles by a numerical technique.A systematical line sampling approach is developed to statistically study the influence of particle shape on the ratio of apparent to actual ITZ thickness (t/t) around a single particle.A fitting equation including the effect of particle shape is derived to extend the capability of the previously developed quantitative formula on t/t around a single convex-shape particle.Then the formula is extended to multisized aggregate system to explore the impact of aggregate size distribution on the statistical mean of apparent ITZ thickness.Finally, analytical formula of ITZ volume fraction (Vrrz) as well as differential effective medium approximation are employed to present the impact induced by the overestimation of ITZ thickness on the exaggeration of concrete diffusivity.The result demonstrates that the nature of particle shape effect on the value t/t is attributed to particle sphericity.The exaggerated degree of Vrrz can be explicitly expressed as the function of fineness and volume fraction of aggregate, actual ITZ thickness, and particle sphericity.And the numerical simulation result reveals that depending on exact values of aggregate shape, size distribution and volume fraction, the diffusivity ratio of ITZ to cement paste matrix, and actual ITZ thickness, the diffusivity of concrete can be overestimated by 10%~40%.The methodology presented in this paper can also be used to study the error of elastic modulus induced by the overestimation oflTZ thickness.
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