چكيده به لاتين
Due to the noticeable production of greenhouse gases in cement and concrete production process in the world, the use of supplementary cementitious materials (SCM) such as metakaolin and zeolite and production of green concrete is inevitable which is led to reduce amount of environmental pollution and improve the mechanical properties of concrete, especially in marine environment. On the other hand, nowadays, the increasing use of plastic materials such as disposable glasses and garbage bags are considered as a major problem in environmental pollution. Therefore, it seems that the simultaneous use of metakaolin and zeolite as SCMs and disposable glasses and garbage bags as fiber material in concrete production can improve concrete mechanical and durability properties, reduce environmental pollution, and delay cracking process, especially in marine environments in the presence of different types of aggressive ions. So, in the current research program, effects of using 0.5 and 1% disposable glasses and garbage bags fibers in the form of ring and strip on flexural behavior of green concrete beams containing zeolite and metakaolin by 10 and 20% as SCMs at 28, 90, and 180 days in tidal environment of the Oman sea was investigated. The results show that by adding 0.5 and 1% ring or strip fibers to green concrete, the maximum load capacity and flexural toughness of the beams increased up to 28 and 48%, respectively. Also, green RC beams containing 1% strip disposable glass fibers had greater flexural toughness up to 11 and 23% than specimens with ring disposable glasses and strip garbage bag fibers, respectively. Furthermore, green beams containing metakaolin had higher maximum load capacity, and flexural toughness than zeolite ones at all days. On the other hand, by increasing different volume fractions and dimensions of ring or strip fibers to the green beams, the crack dimensions were controlled and limited. Finally, the use of recycled fibers (disposable glasses and garbage bags) and SCMs (metakaolin or zeolite) can improve ductility, mechanical properties and crack control in green concrete beams.
