Yangın Sonrası Soğuma Koşullarında Karbonat Yapı Taşlarındaki Mineralojik ve Mikro-Yapısal Değişimlerin Değerlendirilmesi

Öz

Bu çalışmada yangın sonrası farklı soğutma modellerinin etkisi incelenmiştir. Isıtılan kayaçlar; (1) doğal çevre koşullarını temsil etmek için oda sıcaklığında, (2) soğuk mevsimleri temsil etmek için sıfırın altında ve (3) yangına müdahale senaryosu göz önüne alınarak suda soğumaya maruz bırakılmıştır. Çalışmada yapı taşı olarak sıklıkla kullanılan 3 farklı karbonat kayaç, traverten, mermer ve kireçtaşı kullanılmıştır. Kayaçların mineralojik bileşimlerini ve ısıtma-soğutma işlemlerinden sonra mineralojik değişimleri belirlemek için ince kesit incelemeleri ve XRD analizleri yapılmış, mikro-kırık gelişimini ortaya çıkarmak amacıyla SEM görüntüleri kullanılmış, fiziksel ve dayanım özelliklerindeki değişimleri belirlemek için jeomekanik deneyler uygulanmıştır. Soğuma sonrasında, yeni mikro-çatlakların oluşumundan ziyade, mevcut mikro-çatlakların büyüdüğünü görülmüştür. Kayaçların dayanım özellikleri, soğuma süreçlerinden fiziksel özelliklere göre daha fazla etkilenmiş ve en düşük dayanım değerleri suda soğuma sonrası gözlenmiştir. Ani soğuma sonrası traverten ve mermerlerin çekme dayanımı %70-80 arasında azalırken, kil içeren kireçtaşlarında bu değer %30'u geçmemiştir. Sonuçlar, mevcut mikro-çatlakların büyümesi nedeniyle ani soğumanın genellikle yavaş soğumaya göre daha fazla termal hasara neden olduğunu, soğumanın kayaçların termal bozunması üzerinde ısıtmadan daha etkili olduğunu ve kil içeriğine bağlı olarak bu etkinin arttığını göstermektedir.

Anahtar Kelimeler

• soğuma şekli
• karbonat kayaçlar
• termal hasar
• yangın sonrası
• yapı taşı

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