A platform for research: civil engineering, architecture and urbanism
A platform for research: civil engineering, architecture and urbanism
Performance of fly ash based geopolymer concrete made using non-pelletized fly ash aggregates after exposure to high temperatures
Abstract The superior performance of geopolymer paste, mortar and concrete (GPC) when exposed to high temperatures has been well documented. Limitations still exist however due to the use of similar aggregates, coarse and fine, in both ordinary portland cement concrete (OPC) and GPC. The behavior of geopolymer concrete at elevated temperatures can be further improved by using a recently developed lightweight non-pelletized aggregates made entirely from fly ash (named Flashag) as replacement for conventional natural aggregates. Tests for the ambient and residual properties of GPC made using these new aggregates exposed to temperatures up to 1,000 °C were carried out. The obtained results in terms of compressive strength, splitting strength, and modulus of elasticity are reported and compared with those obtained for GPC produced using ordinary natural aggregates as well as with those reported in the literature for OPC concretes. The effects of heat cycling, as well as, duration of heating on the strength and deformational behavior of GPC are also investigated. At ambient temperatures all the three concretes displayed similar properties. At elevated temperatures, however, the performance of GPC made from Flashag was found to be far superior to that of both OPC, and GPC made from ordinary aggregates. Additionally, for up to 4 heating cycles, GPC made with Flashag better retained its strength and stiffness properties as compared to GPC made with ordinary natural aggregates. The study also found that most changes to the strength and microstructure of GPC occur in the first few hours of exposure after which, the duration of heating has no significant effect.
Performance of fly ash based geopolymer concrete made using non-pelletized fly ash aggregates after exposure to high temperatures
Abstract The superior performance of geopolymer paste, mortar and concrete (GPC) when exposed to high temperatures has been well documented. Limitations still exist however due to the use of similar aggregates, coarse and fine, in both ordinary portland cement concrete (OPC) and GPC. The behavior of geopolymer concrete at elevated temperatures can be further improved by using a recently developed lightweight non-pelletized aggregates made entirely from fly ash (named Flashag) as replacement for conventional natural aggregates. Tests for the ambient and residual properties of GPC made using these new aggregates exposed to temperatures up to 1,000 °C were carried out. The obtained results in terms of compressive strength, splitting strength, and modulus of elasticity are reported and compared with those obtained for GPC produced using ordinary natural aggregates as well as with those reported in the literature for OPC concretes. The effects of heat cycling, as well as, duration of heating on the strength and deformational behavior of GPC are also investigated. At ambient temperatures all the three concretes displayed similar properties. At elevated temperatures, however, the performance of GPC made from Flashag was found to be far superior to that of both OPC, and GPC made from ordinary aggregates. Additionally, for up to 4 heating cycles, GPC made with Flashag better retained its strength and stiffness properties as compared to GPC made with ordinary natural aggregates. The study also found that most changes to the strength and microstructure of GPC occur in the first few hours of exposure after which, the duration of heating has no significant effect.
Performance of fly ash based geopolymer concrete made using non-pelletized fly ash aggregates after exposure to high temperatures
Junaid, M. Talha (author) / Khennane, Amar (author) / Kayali, Obada (author)
2014
Article (Journal)
Electronic Resource
English
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Fracture Properties of High-Strength Concrete made with Pelletized Fly-Ash Lightweight Aggregates
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