乾拌夯實壓力對高溫蒸汽催化飛灰水泥的強度發展與水化機理

Abstract

本研究採用台電興達廠F級飛灰取代部份水泥，以不同乾拌夯實壓力，分 別製作Paste及Mortar試體，置入水泥蒸爐內，以不同齡期、不同高溫蒸 汽催化硬固後，探討彼此間對抗壓強度的影響，並以Paste進行熱重量分 析、核磁共振、掃瞄式電子顯微鏡觀測等微觀分析，以配合印證水化機理 及飛灰波索蘭反應。研究結果顯示，約在乾拌夯實壓力4 Kg/cm~^2~z時抗 壓強度最好，其次是7 Kg/cm~^2~z，最差的是1 Kg/cm~^2~z。而催化溫度 以180 ℃時強度最好，其次是150℃， 最差的是120℃。 催化初期飛灰添 加量愈多，水化程度愈低，CH 含量也愈低， 強度也愈低，隨著催化齡期 的增加，水化程度隨著增加，初期CH含量增加但12hr以後隨著飛灰波索蘭 反應而漸減，而強度隨著漸增，催化30hr時飛灰取代量40%之強度已超 過0%，而飛灰取代量100%仍不會因乾拌而促成強度。 The thesis investigates the compressive strength of hardened paste and mortar specimens mixed with cement and class F Fly Ash ( a product of Hsin-Ta Thermal Power Plant of Taiwan Power Company ) . The specimens are prepared under various dry-mix compaction pressure . These specimens were hardened inside autoclave through different duration and high temperature steam catalytic process.These paste specimens was analyzed with ther- mogravimetry ,nuclear magnetic resonance,and scanning electron microscope to verify its hydration mechanisms and pozzolanic reaction. Based on experimental results , it is concluded that maximum compressive strength was obtained when dry-mix compaction pre- ssure was around 4 kg/cm~^2~z , and catalytic temperature was 180℃.In the early stage of catalysis,more fly ash cement used with lower degree of hydration would result in lower amount of CH and weaker strength . As duration of catalysis increased , both degree of hydration and amount of CH would decrease. However,after 12 hours the amount of CH would decrease, due to pozzolanic reaction compressive strength of the specimens would increase.After 30 hours,the strength of specimens with 40 % fly ash was greater than the strength of specimens without fly ash. Dry-mix pure fly ash specimens showed no strength at all.