Özet:
Composite materials are widely used with many purposes in contemporary engineering applications. Lightweight composites are mostly used in aerospace and military engineering applications but as well as in construction industry. Reducing the dead loads of the structures has numerous advantages. For this purpose there are several different lightweight aggregates used in the literature. In the context of the current study pumice type of lightweight aggregates used with normal weight aggregates. Steel fibers with different aspect ratios (55, 57 and 65) having the length 30mm, 36mm and 60mm respectively used with two different volume fractions of 0.5% and 1%.Fresh state properties as well as hardened state properties are investigated. Several mechanical properties such as compressive strength, indirect tensile strength, modulus of elasticity etc. are presented. Three different type of fracture tests conducted; namely 3 point bending test with notched specimens, Barcelona test and Generalized Barcelona test. Effect of fiber addition, fiber volume fraction and aspect ratio are investigated evaluating toughness of specimens. Considering Barcelona tests both total circumferential opening displacement (TCOD) and axial displacements used to evaluate the ductile behavior of concrete. Finally, it was observed that increase in fiber volume fraction and aspect ratio significantly improves mechanical and fracture properties of pumice lightweight aggregate concrete.
