【摘要】 借助SEM/EDXA、IR和XRD等测试手段,以活性加拿大白云质石灰岩和非活性的安徽白云石为集料,研究了水泥石-白云石集料界面的显微结构。结果表明,不论白云石集料是否具有碱活性,其与水泥石的界面结构是相似的,都可以分为四层。为此,本文提出水泥石-白云石集料界面显微结构的四层模型:渗透层、界面反应层、结晶层和易干裂层,其中结晶层与易干裂层之间碱含量最高、C/S比最低(约1—1.5),是界面区的薄弱处。同时,界面水泥侧的易干裂层对混凝土的界面性能(如粘结强度等)可能有一定影响。更多还原

【Abstract】 In the paper, an active dolomitic limestone from Kingston, Canada and a non-active dolomite from Anhui Province, China, were selected as samples, and the interfaeial micrestructures between hardened cement paste and these two kinds of dolomites were studied by means of SEM/EDXA, IR, XRD and other techniques. From the results obtained, the microstructures are similar to each other and can be divided into four layers, whether the dolomite is active or not.Thus a model for the four-layer interfacial microstructure is proposed. The four layers are: the permeable layer, the reaction layer, the crystallization layer and the layer liable to cracking. The weakest location in the interracial zone is the interface between the crystallization layer and the layer liable to cracking at which the alkali content is the highest and the C/S ratio (approximately 1—1.5) is the lowest.Furthermore,the cracking layer adjacent to hardened cement paste may affect the interfacial properties oi concrete, such as bond strength.更多还原