DefinePK

Abstract

Concrete Hollow Core Slabs (HCS) is one type of roofing that are widely used in all the world in residential and industrial buildings due to, the reduction of self-weight, and the economic and thermal insulation of these building units. The recycling of waste from construction and demolition of old buildings minimizes the environmental problems and encourages sustainability. The aim of this study is to produce sustainable HCS specimens reinforced with mono or hybrid (triple) fibers of different types and dimensions and studying their structural behavior. Fibers used include, hooked end steel fiber with aspect ratio of 60 (type S1), micro-steel fiber with aspect ratio of 65 (type S), and polypropylene fiber (PP) with aspect ratio of 667. Five hollow core slabs (HCS) were casted including, three HCS specimens containing crushed clay brick as coarse Lightweight Aggregate (LWA), the first one is plain HCS specimen (without fibers), the second is HCS with mono fiber (macro-steel fiber type S1 with volume fraction of 0.75%), and the third is HCS specimens reinforced with triple hybrid fiber (0.25% steel fiber type S1+ 0.25% polypropylene fiber + 0.25% steel fiber type S), two HCS specimens with artificial LWA, one is plain HCS specimen (without fibers) and the other is one HCS specimens reinforced with triple hybrid fiber (0.25% steel fiber type S1+ 0.25% polypropylene fiber + 0.25% steel fiber type S) were prepared. Load-deflection relationship, first crack and ultimate loads, and ductility ratio of HCS specimens were studied. Hollow core slab specimens reinforced with fibers show considerable improvement in ductility ratio in ductility ratio relative to plain specimens. The percentages of increase in ductility ratio of HCS specimen containing crushed clay brick LWA reinforced with mono steel fiber and specimen reinforced with triple hybrid fiber are 297.4% and 351.3% respectively, while for HCS specimen with artificial LWA reinforced with triple hybrid fiber is 386.5% relative to the corresponding reference HCS specimen. Generally, the experimental results indicate that HCS specimens containing produced LWA have better properties than specimens containing crushed clay brick LWA. Generally, the results indicate that sustainable HCS reinforced with fibers can be used as roofing system in buildings.