蒸汽養護對鹼-骨材反應之影響

The Influence of Steam Curing on Alkali-Aggregate Reaction

邱薰頤(Hsun-I Chiu)

指導教授 ： 田永銘

國立中央大學/工學院/土木工程學系/碩士(2006年)

摘要

本研究為探討蒸汽養護對鹼-骨材反應之影響，採集海岸山脈安山岩與花蓮和平溪骨材，利用蒸汽養護方式進行ASTM C227與ASTM C1293試驗。主要討論下列各項因素對鹼-骨材反應之影響：（1）鹼含量；（2）蒸汽養護；（3）端面束制；（4）前置期。
由試驗結果發現，海岸山脈安山岩與和平溪之骨材皆有鹼-骨材反應潛能，試體之總鹼含量越高則膨脹量越大。混凝土於蒸汽養護過程中將使膨脹量在早期即被激發，減緩晚期膨脹量之發生，使試體膨脹應變量小於未進行蒸汽養護之試體，且表面裂縫與反應膠體數量較少，由此可知蒸汽養護對減緩混凝土之鹼-骨材反應有一定之成效。若仿照一般預鑄廠之施作方式，將混凝土連同模具一併進行蒸汽養護，則端面束制之試體膨脹量明顯小於非端面束制之試體，而蒸汽養護之前置時間越長，則水化作用較完全，試體膨脹量亦較小，可降低混凝土構件因鹼-骨材反應所引致之膨脹量。

關鍵字

鹼-骨材反應 ； 蒸汽養護 ； 前置期 ； 端面束制

並列摘要

This study is mainly discussing how the steam curing affects on the Alkali-Aggregate Reaction. Andesite from the coastal range and aggregate of Heping River were used in the trial of ASTM C227and ASTM C1293 via the progress of steam curing. The four factors were discussed on the affects of the Alkali-Aggregate Reaction: (1)alkali content; (2)steam curing; (3)constrained end; (4)delay period.
The result of this study is that both of the andesite from the coastal range and the Aggregate of Heping River have the potential to represent the Alkali-Aggregate Reaction. IF the percentage of alkali content is higher, the scale of expansion would be larger. If the concrete made by either andesite from the coastal range or the Aggregate of Heping River were treated with steam curing, the expansion in the early stage would be stimulated rapidly, and the expansion of the latter stage would be suspended, allowing the overall scale of expansion to be smaller than the non-steam cured specimen. On the other hand, there would be less crack and reactive gel in the specimen treated with steam curing. So it is obvious to conclude that the steam curing can effectively reduce the Alkali-Aggregate Reaction in concrete. By imitating the methods of making concrete in the pre-casting factories, that is, allowing the concrete along with the patterns to be treated with steam curing, the scale of expansion of the constrained end in the specimen would be smaller than the scale of expansion of the non-constrained end. And if the delay period of the steam curing is longer, the scale of expansion of the specimen would be smaller. In that way, the scale of expansion in the concrete structure induced by the Alkali-Aggregate Reaction would be reduced.

並列關鍵字

Delay Period ； Constrained End ； Steam Curing ； Alkali-Aggregate Reaction

參考文獻

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19. ACI Committee 517, “Low Pressure Steam Curing,” ACI Journal, Proceedings, Vol. 60, No. 8, pp. 953-986 (1963).

20. ACI Committee 517, “Recommended Practice for Atmospheric Pressure Steam Curing of Concrete,” ACI Journal, Proceedings, Vol. 66, No. 8, pp. 629-646 (1969).

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