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