混凝土中水泥漿和顆粒骨材界面特性之研究

Abstract

本研究的主要目的在於探討各種齡期及環境下，混凝土中水泥漿和顆粒骨材界面的水化產物及孔隙對各項工程性質之影響。利用TGA量測燒失量，判定水化程度及氫氧化鈣結晶含量；SEM觀測，進行晶相外觀形狀分析，配合立體鏡及視差尺的運用，以明瞭過渡區中晶相結構中的厚度變化； EDS分析水化產物之化學組成； NMR量測C-S-H之陰離子鍵結長度；以分析出不同齡期下，界面位置之微觀結構。 研究結果顯示，在初期的水化過程中，水泥漿與顆粒骨材界面處100μm範圍間，孔隙與水化生成物呈現一間歇交錯式的成長。孔隙由初期水化時的大團聚簇成塊狀、條狀的分佈，漸成不定形的小型塊狀組織發展。同時藉由「立體像對」的製作，發現距顆粒骨材邊緣處起算約25μm之後，其水化生成物之厚度將隨著遠離顆粒骨材的距離而有所增加；而在25μm的範圍內，於初期水化階段時，則有較多顆粒狀的未水化水泥顆粒及呈塊狀晶體的CH堆積於其處，隨齡期的漸增，鈣釩石及單硫鋁酸鈣水化物增多，之後C-S-H（III）及結晶型CH漸取代鈣釩石及單硫鋁酸鈣水化物而附積於顆粒骨材邊緣，其間仍多孔隙存在，界面處鬆散的結構組織會隨著齡期發展而轉趨緻密。

The major aim of the study is to explor the effect that under the different conditions and ages, the hydration products and the void of the hydration products and aggregate contact layer. To measure the loss of combustion by TGA, and to determine the degree of hydration and the contents of Ca(OH)2 ; observing SEM for morphological and cross section profile features by using stereoscope and parallax ruler to understand the change process of the morphological thickness. Analysing the composition of the hydration products by EDS, and the length of C-S-H gels by NMR to determine the microstructure of interface weave. The research result shows: the initial process of hydration between 100μm aggregate contact layer, this is intermittent growth. At first, the void is thick lump at initial time, then become indefinite, smaller, thin lump. Relying on the stereograph, at the 25μm interval between the border of the aggregate, the thick of hydration products increased by adding the distance from the aggregate. In the range of 25μm , there are more pellet cement not or not yet to hydration, and to become lump morphological profile features CH at initial hydration process; by adding the ages of hydration, it produces more AFt and AFm. The C-S-H(III) and crystallize CH gradually to replace of the AFt and AFm stick to the border of aggregate exsited porosity, and by the ages growthful, the loose structure metamorphose densely.