二氧化碳養護對混凝土性質影響之研究

本研究以兩種配比強度混凝土製作成Φ5 × 10 cm、Φ10 × 20 cm、Φ15 × 30 cm三種不同尺寸之圓柱試體進行比較，將試體澆置完成後擺放四個小時完成初凝後立即拆模，放入加壓二氧化碳氣體環境下進行加速養護試驗，並控制三種二氧化碳濃度、三種加壓時間、兩種加壓壓力作為養護環境參數，碳養護完成之後放入飽和石灰水中養護。本研究探討混凝土圓柱經過不同環境參數之二氧化碳加速養護後，其抗壓強度、彈性模數、破裂模數、碳化深度之影響。從實驗結果可以發現，Φ15 × 30 cm試體抗壓強度表現最佳者為二氧化碳濃度50%，養護1小時，養護壓力2 bar（kgf/cm^2），其3、7、28、90天齡期抗壓強度分別較控制組增加29%、38%、8%、11%。不論是否經過碳養護，彈性模數及破裂模數差異低於5%，而試體經過碳養護之後，有深度約1.71 mm的中性化現象。由本試驗結果可知，試體經過碳養護之後，抗壓強度較一般水養護試體有強度提升效果，且試體表面有中性化現象，而彈性模數及破裂模數受碳養護影響較小。

關鍵字

二氧化碳養護；破裂模數；中性化；彈性模數

並列摘要

This research used two concrete strengths included three different sizes with ϕ5×10 cm、ϕ10×20 cm and ϕ15×30 cm to compare with each other. After casted in cylinder model for four hours in air to finish initial setting program, removed form immediately then put specimens into pressure chamber which injected the high carbon dioxide gas to start doing the fast curing test with factors included three carbon dioxide concentrations, three curing time and two curing pressures. Finally, put CO_2-cured specimens in the saturated limewater to keep after curing. This research includes compressive strength, elastic modulus, rupture modulus and carbonated depth for different cylinder concrete sizes in different environment factors of CO_2 curing. According to the result, the best compressive strength of the ϕ15×30 cm specimen is about 100% of carbon dioxide concentration, 1 hour of curing time, 2 bar(kgf/cm^2) of curing pressure. When the curing day came to 3, 7, 28 and 90, the compressive strength of the CO_2-cured specimens were higher than the hydraulic specimens about 29%, 38%, 8% and 11%. The elastic modulus and rupture modulus of CO_2-cured specimens had less difference in 5% with hydraulic specimens and the CO_2-cured specimens had carbonated depth about 1.17 mm. According to the result, the compressive strength will be stronger after CO_2 curing. The CO_2-cured specimens have carbonated depth phenomenon and the elastic modulus and rupture modulus have less effect by CO_2 curing.

並列關鍵字

carbon dioxide curing ； rupture modulus ； carbonation degree ； elastic modulus

國際替代計量

二氧化碳養護對混凝土性質影響之研究

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