老混凝土中骨料-水泥界面过渡区(ITZ)(Ⅰ)——元素与化合物在ITZ的富集现象

利用扫描电子显微镜（SEM）、电子探针（EPXM）和电子能谱（EDXA）对骨料颗粒和水泥浆体界面过渡区（ITZ）进行了研究，研究的重点是老混凝土中骨料－水泥界面过渡区的微观结构特征和成份分布，结果表明，老混凝土由于在成熟度高，其ITZ中水化物十分丰富，密实度高。ITZ内部和外部的水化产物组成存在一定的差别，表现在Ca,K和Fe等元素富集于ITZ，而Si元素在此区域的含量相对较低，对于特定的元素或物质在ITZ中的富集现象的研究，有助于提高对混凝土材料稳定性的认识。

Aggregate-Cement Interfacial Transition Zone (ITZ) in Old Concrete(Ⅰ) --Concentrations of Elements and Compounds to the ITZ

Interfacial Transition Zone (ITZ) between aggregate particles and cement paste in an old concrete was studied by scanning electron microscope (SEM), electron probe X ray micro analyzer (EPXM) and the energy dispersive X ray analyzer (EDXA). The study was focused on the microstructural characteristics and composition distribution in the ITZ. The test results showed that there were adequate hydrates in the ITZ resulting in a dense ITZ structure, due to the long term hydration. Obvious difference of chemical compositions existed between inside and outside of the ITZ. Elements Ca, K and Fe etc. tended to accumulate around the interface whereas Si appeared to be of lower content in the ITZ than out the ITZ.