TY - JOUR
T1 - Compressive strength development and durability properties of high-calcium fly ash incorporated concrete in extremely cold weather
AU - Pushpalal, Dinil
AU - Danzandorj, Sunjidmaa
AU - Bayarjavkhlan, Narantogtokh
AU - Nishiwaki, Tomoya
AU - Yamamoto, Kazuya
N1 - Funding Information:
The authors would like to thank Denka Company Limited, for analyzing fly ash samples. The cooperation of Mr. Takamichi Miyazaki of School of Engineering, Tohoku University in SEM observation is gratefully acknowledged. This work was supported by M-JEED (Mongolia Japan Engineering Education Development) joint research program of “Utilization of Mongolian fly ash in construction industry for greener future.”
Publisher Copyright:
© 2021 Elsevier Ltd
PY - 2022/1/17
Y1 - 2022/1/17
N2 - This research paper takes into account of three mineralogically different high calcium fly ashes (HCFA) consisted of anhydrite, generated in power plants in Ulaanbaatar, Mongolia. The purpose of this research is to understand how the morphology and mineralogy of HCFA influence the fresh and hardened properties of concrete; how pre-curing condition influences the long term strength development in different seasons; and to investigate the durability of HCFA concrete in extreme outdoor exposure conditions and freezing and thawing environment. Compressive strength development of fly ash concretes up to 540 days in extremely cold weather, strength dependence on pre-curing condition, freezing and thawing durability and the influence of ash mineralogy on durability were investigated. As a part of the investigation, the concrete specimens were kept outdoor at sub-zero temperature for more than four months. This paper concludes that strength approximately equal to that of the control can be obtained at early ages by 20 wt% replacement of total cementitious content by fly ash. When a comparison is made with equal mixtures, but equal pre-curing, winter concrete can only be achieved approximately 80% strength of autumn concrete after 3 months and then no considerable improvement happens even at one year. When a comparison is made with equal mixtures, but different pre-curing, the specimens exposed to the outdoor a day after placement show a permanent strength loss of 24%, with compare to the specimens cured in water at 20 °C for 28 days before exposing to the outdoor in winter. Durability factors of all fly ash incorporated concretes determined by freezing and thawing test were in the range of 78–91 at 300 cycles, satisfying the threshold in which concrete is likely to perform well.
AB - This research paper takes into account of three mineralogically different high calcium fly ashes (HCFA) consisted of anhydrite, generated in power plants in Ulaanbaatar, Mongolia. The purpose of this research is to understand how the morphology and mineralogy of HCFA influence the fresh and hardened properties of concrete; how pre-curing condition influences the long term strength development in different seasons; and to investigate the durability of HCFA concrete in extreme outdoor exposure conditions and freezing and thawing environment. Compressive strength development of fly ash concretes up to 540 days in extremely cold weather, strength dependence on pre-curing condition, freezing and thawing durability and the influence of ash mineralogy on durability were investigated. As a part of the investigation, the concrete specimens were kept outdoor at sub-zero temperature for more than four months. This paper concludes that strength approximately equal to that of the control can be obtained at early ages by 20 wt% replacement of total cementitious content by fly ash. When a comparison is made with equal mixtures, but equal pre-curing, winter concrete can only be achieved approximately 80% strength of autumn concrete after 3 months and then no considerable improvement happens even at one year. When a comparison is made with equal mixtures, but different pre-curing, the specimens exposed to the outdoor a day after placement show a permanent strength loss of 24%, with compare to the specimens cured in water at 20 °C for 28 days before exposing to the outdoor in winter. Durability factors of all fly ash incorporated concretes determined by freezing and thawing test were in the range of 78–91 at 300 cycles, satisfying the threshold in which concrete is likely to perform well.
KW - Anhydrite
KW - Compressive strength
KW - Dynamic modulus of elasticity
KW - Fly ash
KW - Freezing and thawing
KW - Outdoor exposure
KW - Permanent strength loss
KW - Ready mixed concrete
KW - SEM
KW - XRD
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U2 - 10.1016/j.conbuildmat.2021.125801
DO - 10.1016/j.conbuildmat.2021.125801
M3 - Article
AN - SCOPUS:85120468262
VL - 316
JO - Construction and Building Materials
JF - Construction and Building Materials
SN - 0950-0618
M1 - 125801
ER -