YÜK UYGULANMAMIŞ VE PLASTİK DEFORMASYONA UĞRATILMIŞ HTPP-ECC’LERİN TERMAL YALITIM PERFORMANSI ÜZERİNE KARŞILAŞTIRMALI BİR İNCELEME

Abstract

Mühendislikçe geliştirilmiş çimentolu kompozitler (ECC) mikro-mekanik olarak tasarlanan geleneksel betona kıyasla yüksek performanslı kompozitlerdir. Mevcut literatürdeki önemli sayıda araştırma, ECC'lerin mekanik performansının ve sünekliğinin geliştirmesine odaklanmaktadır. Bu çalışmada, ECC'nin HTPP-ECC isimli özel bir türünün termal özellikleri araştırılmıştır. Bu amaç doğrultusunda, prizmatik kompozitler hazırlanmış ve termal iletkenlik deneyleri gerçekleştirilmiştir. Deney sonuçları mevcut literatürden elde edilen verilerle kıyaslanmıştır. Ayrıca, HTPP-ECC'lerin mekanik performansı ve çoklu çatlama yeteneği eğilme yükü altında test edilmiştir. Mevcut literatüre ek olarak, HTPP-ECC'lerin termal ısı yalıtım performansı, çatlamamış (eğilme testinden önce), çatlatılmış (tepe yüklemesinden sonra yük düşüşü % 10'a kadar) ve göçmüş (numunenin altında 5 mm genişliğinde büyük çatlak oluşana kadar) durumlarda gerçek saha koşullarını taklit eden bir yalıtım testi kurulumu kullanılarak test edilmiştir. Kararlı haldeki mikro-çatlakların HTPP-ECC'nin ısı yalıtım performansı üzerindeki etkisi değerlendirilmiştir. Sonuç olarak, bu çalışmada üretilen HTPP-ECC'lerin plastik olarak deforme olmuş halde bile çimento esaslı diğer materyallere kıyasla daha iyi bir termal iletkenlik performansı sergilediğini göstermiştir. Ayrıca, HTPP-ECC'ler mikro-çatlaklı halde bile gelişmiş mekanik özelliklere ve çoklu kırma yeteneğine sahip umut verici alternatif bir ısı yalıtım malzemesi olarak etkili bir ısı yalıtımı performansı sergilemiştir.

Keywords

• Termal özellikler
• Mühendislikçe geliştirilmiş çimentolu kompozitler
• HTPP
• lif
• uzun dönem

A COMPARATIVE STUDY ON THE THERMAL INSULATION PERFORMANCE OF UNLOADED AND PLASTICALLY DEFORMED HTPP-ECC

Abstract

Engineered Cementitious Composite (ECC) is a type of micro-mechanically designed, high performance composite compared to conventional concrete. A considerable number of research in the existing literature concentrate on mechanical performance and ductility improvement of ECCs. In this paper, thermal properties of special type of ECC incorporating high tenacity polypropylene fiber by 2% of total matrix volume (HTPP-ECC) have been investigated. For this purpose, prismatic composites were prepared and thermal conductivity tests were performed. Tests results were compared with the data obtained from existing literature. The mechanical performance and multiple cracking ability of HTPP-ECCs were also tested under bending load. In addition to the existing literature, thermal heat insulation performance of HTPP-ECCs have been tested at virgin (before bending test), cracked (up to 10% of load drop after peak load) and failed (up to 5 mm major crack width at the bottom of the specimen) state by using an insulation test setup which simulates actual site conditions. The effect of steady state micro-cracking on the thermal insulation performance of HTPP-ECC was evaluated. Results showed that, HTPP-ECCs produced in this study has better performance in terms of thermal conductivity when compared to other types of cement-based materials even at the plastically deformed state. Also, HTPP-ECCs exhibited an effective thermal insulation performance even in micro-cracked state as a promising alternative thermal insulation material with improved mechanical properties and multiple cracking ability.

Keywords

• Thermal properties
• Engineered Cementitious Composites
• HTPP
• fiber
• long term

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