Agrega Tane Boyut Dağılımı ve PP Lif Kullanımının Betonda Plastik Rötre Çatlağı Oluşumu Üzerine Etkileri

Yıl 2022, , 611 - 618, 30.09.2022

Hasan Nuri Türkmenoğlu , Hakan Nuri Atahan

https://doi.org/10.24012/dumf.1138905

Öz

Plastik rötre betonun henüz sertleşmediği zaman diliminde meydana gelen yüzeysel bir çatlak türüdür. Temel nedeni beton yüzeyindeki buharlaşma hızının betonun terleme hızından yüksek olmasına bağlı olarak yüzeyin kurumasıdır. Böylece beton yüzeyi büzülmeye başlarken, alt kısımlarda kalan beton plastik kıvamda olduğu için yüzey ile benzer büzülmeyi gösteremez ve yüzeyde harita şeklinde çatlaklar oluşur. Yapılan çalışmada, toplam agrega hacminin sabit olduğu 3 farklı agrega dağılımına sahip beton ve 2 farklı polipropilen lif değişik oranlarda kullanılarak plastik rötre üzerine etkileri incelenmiştir. Deneylerde yöntem olarak ASTM C1579 standardı esas alınmış olup çatlak parametreleri deney sırasında çekilen fotoğraflar işlenerek elde edilmiştir. Elde edilen sonuçlar daha iri agrega dağılımının çatlak oluşumunu önlemede daha başarılı olduğunu ortaya koymuştur. Fakat çatlağı önlemek için kullanılan liflerin etkinliği agrega dağılımı irileştikçe azalmıştır. Diğer yandan kullanılan lifler plastik rötre çatlağını belirgin bir şekilde engellemişlerdir fakat aynı boydaki liflerden narinliği daha yüksek olan monofilament lifin kullanıldığı betonlardan daha iyi sonuçlar elde edilmiştir.

Anahtar Kelimeler

beton, plastik rötre, çatlak, çatlak azalma oranı, polipropilen lif

Kaynakça

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