金瓜石礦區熱水換質岩石骨材性質之研究

金瓜石地區的岩石多因熱水作用而受到不同程度的矽化、黏土化、綠泥石化等換質作用，其骨材性質應與新鮮岩石不同，本研究針對這些岩石進行各項骨材性質試驗，以瞭解經過熱水換質作用後之岩石其性質是否滿足營建工程用骨材之需求。本研究於金瓜石各種換質作用分佈區域採取矽化、黏土化、綠泥石化及新鮮安山岩與矽化、黏土化及新鮮砂岩樣品各兩件，經由XRD鑑定及XRF成分分析確認樣品性質後，依照規範進行各項骨材試驗。試驗結果顯示黏土化安山岩及砂岩富含大量黏土，性質軟弱，不適為各種骨材試驗，故歸類為劣質骨材。綠泥石化及新鮮安山岩在XRF成分分析性質相近，骨材試驗兩者皆符合規範要求，其中綠泥石化安山岩受熱水作用影響，在骨材堅硬程度及強度性質上要比新鮮安山岩佳。矽化安山岩及砂岩經強度及耐久性試驗結果顯示其性質非常堅硬，但矽化安山岩由於受過熱水換質作用，使其岩石變為多孔性，比重2.35左右，雖不符合CNS之要求，但其質輕強度高之特性，與一般常用骨材不同，應仍具有工程之適用性。

關鍵字

金瓜石；熱水換質作用；骨材性質

並列摘要

A significant amount of rocks in Chinkuashih mines was hydro-thermally altered to varying degree of silicification, argillication or propyllitication. The aggregate characteristics of these altered rocks are different from fresh unaltered rocks. A series of tests was conducted to determine the aggregate properties of wall rocks and waste fills in this area and to evaluate these hydro-thermally altered rocks for industrial applications. Two samples each of silisified, argillic, propyllitic and fresh dacite and sandstone were collected from Chinkuashih mines. After an XRD mineral examination and XRF composition analysis, CNS and ASTM specified aggregate property tests and alkali-aggregate reaction tests were conducted. The results show that the argillic dacite and argillic sandstone have a large amount of clay minerals not suitable for aggregate experiments. They are classified as inferior aggregates. The propyllitic and fresh dacites have similar composition and aggregate properties that satisfy the requirements of the CNS codes. After hydrothermal alteration, propyllitic decite has better aggregate strength than fresh decite. Both silisified dacite and sandstone are very hard and have aggregate properties suitable for civil engineering applications.

並列關鍵字

Chinkuashih ； Hydrothermal alteration ； Aggregate characteristics

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