Şiddetli çevrelere maruz kalmış sargılı ve sargısız geopolimer betonun mekani̇k performansı ve durabilitesi

This study reports the mechanical properties and durability of unconfined/confined sustainable geopolymer concrete (GPC) exposed to chemical attack under static and cyclic loadings. A low calcium (Class F) fly ash incorporating nano-silica was activated by a combination of sodium silicate and sodium hydroxide solutions to make the GPC. Unconfined/confined ordinary Portland cement concrete (NC) counterparts were also made for comparison purposes. The confined GPC/NC specimens were wrapped by one/three layers of basalt/carbon fiber-reinforced polymers (BFRP/CFRP). Effects of type and number of wrapping layers, along with wrapping and testing ages on the mechanical properties and durability of confined GPC/NC were investigated. In addition, microstructure of the unconfined/confined GPC specimens was compared with that of the unconfined NC counterparts. The results showed confinement of the GPC with BFRP/CFRP fabrics enhanced the strength, ductility and durability of the GPC specimens exposed to chemical attack. The GPC specimens confined with CFRP fabric were found more ductile and durable than specimens confined by BFRP fabric. In addition, the GPC specimens confined with three layers of FRP fabrics were found more ductile and durable than that of the specimens confined with only one-layer. Further, the unconfined/confined GPC specimens were more durable than the corresponding unconfined/confined NC.