乾拌蒸氣催化爐石水泥漿體/砂漿過渡區物化性質之初步研究

Abstract

本研究係以高溫高壓之水蒸氣催化不同爐石取代量之爐石水泥漿'水泥砂 漿之乾拌試體,並藉由SEM,EDAX及微硬度探究乾拌蒸氣催化工法過渡區之 微觀性質,並添加不同矽材(石英粉,稻殼灰及水淬爐石)以研究其在乾拌蒸 氣催化工法之影響.研究結果顯示:(1)乾拌蒸氣催化工法中漿體與花崗岩, 石灰岩或標準砂之粘結力均極弱,由SEM觀察得知,乾拌蒸氣催化下水泥與 骨材間接著面之水化產物為結晶狀且節構疏鬆,故水泥泥漿體與骨材間之 粘著力極差.(2)結晶二氧化矽(過200號篩之石英粉),對乾拌蒸氣催化工法 之水泥漿體抗壓強度影響極大,最佳添加量約30%,而無定形二氧化矽(水淬 爐石)經乾拌蒸氣催化後之水泥漿體抗壓強度不佳.(3)不論乾拌或溼拌之 水泥砂漿在距標準砂表面附近之漿體均有較高之微硬度,可能與此區生成 結晶狀水化物有關.(4)乾拌蒸氣催化後之爐石水泥砂漿,在開始7天內強度 會遞減,之後強度在逐漸回復. This thesis studies the transition zone properties of slag- cement pasteand different types of aggregate (limestone,granite and Ottawa sand) bydry-mixed/steam-injection (DM/SI) process.The micro-properties of thetransition zone were investigated of DM/ SI specimens by means of SEM,EDAX and microhardness.By addition different silicate materials (quartzflour,rice husk ash and blast furnace slag) to the paste,and researchwere conducted to study their effects on it's compressive strength.Testresults are indicated that:In the DM/SI process ,the bond strength betweenpaste and aggregate is extremely poor.By SEM observation ,the hydrated production on the facture surface between paste and aggregate has crystalform and loosly structure results in poor bond.Crystal silicate (quartzflour pass through no.200 sieve) increase the compressive strength of DM/SI paste specimens.The optimum amount of addition is about 30%.Mixingamorphouse silicate (blast furnace slag) with cement through DM/SI processyield samples with poor compressive strength.Both DM/SI method and wet-mixed method with higher microhardness near sand surface.This result isprobably due to crystal hydrated production form in this area.After DM/ SIprocess,the compressive strength of mortar specimens will decrease in the beginning 7 days,then the specimen slowly recover it's strength.