, Page 0-0 (1)

Volume Title: ICASGE2017

DOI: ICASGE-MAT

Mariam Farouk Ghazy; Metwally Abd Allah Abd Elaty; Hadeer A. El-Khouli

Geopolymer concrete (GPC) is considered the most promising eco-friendly material alternative to Ordinary Portland Concrete (PC) and an opportunity to utilize by-products in concrete manufacturing. One key driver in geopolymer development is the desire to reduce greenhouse gas emissions from the production of PC products. Geopolymers exhibit good mechanical properties, durability and thermal resistance. Due to the relatively low tensile strength of GPC, fibers may be added to overcome this deficiency. This study is directed to investigate the influence of adding different fiber types (steel, polypropylene, and hybrid) as well as different fiber contents (0, 1, and 1.5 %) to GPC mixes on the mechanical properties. The investigated properties included compressive, splitting tensile and flexural strengths. Moreover, flexural behavior of reinforced GPC beams cast with fiber reinforced GPC mixes was studied. The first crack load, the ultimate load, the crack pattern, the load-deflection and the load-steel strain responses at various stages of loading were conducted. The test results showed that enhancements were obtained due to fibers addition. Steel fibers showed the most improvement in the mechanical properties. The percentages of enhancements were 37.52%, 83.04% and 34.33% for compressive, splitting and flexural strengths over the control mix (GPC), respectively. On the other hand, up to 60% and 21.34% enhancements in the load capacity were recorded for reinforced GPC beams containing 1.5% steel fiber at first crack and ultimate load, respectively. The energy absorption capacities of the tested beams were also improved due to addition of fibers, among the used fiber types polypropylene fibers showed the best improvement in the energy absorption capacity. Generally, the presence of fibers reduced the cracks width and enhanced the failure to a more ductile one.

Geopolymer concrete steel fiber; polypropylene fiber; hybrid fiber; mechanical properties; flexural behavior