Effect of circulating fluidized bed combustion ash on the properties of roller compacted concrete

Chi, Maochieh; Huang, Ran

doi:10.1016/j.cemconcomp.2013.10.001

Cited by 89 publications

(32 citation statements)

References 24 publications

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“…Li et al revealed that CFB fly ash has high pozzolanic reactivity and can be used as a cement admixture [7]. Chi et al indicated that CFB fly ash can increase water absorption and effectively reduce initial surface absorption [3]. Additionally, CFB fly ash has a positive effect on the compressive strength, splitting tensile strength, and sulfate attack resistance of hardened, roller-compacted concrete.…”

Section: Introductionmentioning

confidence: 99%

“…Numerous power stations use limestone as a sorbent for the SO 2 released during coal combustion [3]. CFB fly ash differs from typical coal combustion by-products in that (1) it lacks the high content of f-CaO present in atmospheric fluidized bed combustion ash, thus preventing it from reacting vigorously with water, and lacks the high content of SO 3 (usually anhydrite) present in both atmospheric fluidized bed combustion ash and pressurized fluidized bed combustion ash; (2) it consists of few spherical particles because the temperature in CFB combustion boilers (often 800-900 °C) is lower than that in pulverized coal-fired boilers (often 1300-1500 °C); and (3) it self-cements [4,5]. CFB fly ash is potentially a valuable source of major oxides, such as CaO and SiO 2 , but technology for recovering CFB fly ash is unavailable.…”

Section: Introductionmentioning

confidence: 99%

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Utilization of Circulating Fluidized Bed Fly Ash as Pozzolanic Material

Lin¹,

Cheng²,

Ho³

et al. 2017

TOCIEJ

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A circulating fluidized bed (CFB) boiler generates energy by burning petroleum coke. Because burnt petroleum coke has a high sulfur content, limestone is added to the boiler to reduce the emittance of sulfur dioxide through desulfuration. The residue collected from the boiler is called CFB ash. CFB boilers in Taiwan can produce 328,000 tonnes of CFB fly ash per year. In this study, the pozzolanic characteristics of CFB fly ash were investigated by blending CFB fly ash and ordinary Portland cement (OPC). The CFB fly ash was mainly composed of CaO, SO 3 , and SiO 2 in concentrations of 37.8%, 9.2%, and 2.2%, respectively. The crystals of CFB fly ash contained 3CaO.SiO 2 , 2CaO.SiO 2 , Ca(OH) 2 , C-S-H (Tobermolite), and Ettringite. The results revealed that applying the toxicity characteristic leaching procedure to CFB fly ash renders it suitable for use in blended cement. At later curing ages (90 days), the pore volumes of both the OPC and the CFB-fly-ash-blended cement pastes (CFBFABCP) decreased as the curing time increased. A possible explanation is that C 3 S and C 2 S were consumed to form C-S-H gel, resulting in an increase in the Q 1 and Q 2 groups identified by 29 Si Nuclear Magnetic Resonance (NMR) spectroscopy. Furthermore, the peak of the Q group decreased, but those of the Q 1 and Q 2 peaks increased with an increasing curing time. The pozzolanic activity of the CFBFABCP containing 10% CFB fly ash indicates that it is a suitable substitute for OPC in blended cement.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Utilization of Circulating Fluidized Bed Fly Ash as Pozzolanic Material

Lin¹,

Cheng²,

Ho³

et al. 2017

TOCIEJ

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“…Meanwhile, these slag mortars showed a greater increase of strength than control mortar due to the absence of internal damage and the reactivity of the fine fraction of the slag aggregate [24]. For the fly ash case, bottom ash/circulating fluidized bed combustion ash concrete mixtures also showed better resistance to external sulphuric acid attack [47,48]. It was considered when the level of combined high-calcium fly ash and slag reached to 60% of the total cementitious materials, a significant reduction of expansion was observed [49].…”

Section: Deterioration Caused By Sulfate Attackmentioning

confidence: 93%

Recent durability studies on concrete structure

Tang

Yao

Andrade

2015

Cement and Concrete Research

432

121

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“…e use of chemical activators such as sulfate and other materials can improve the activity of desulfurization slag but increase volume expansion. e expansion in late hydration may cause the strength to be reduced or even eliminated [13][14][15]. Moreover, there is seldom report on study of CFBC desulfurization slag in mortar or concrete as an additive.…”

Section: Introductionmentioning

confidence: 99%

Research on the Expansion Characteristics and Compressive Strength of Mortars Containing Circulating Fluidized Bed Combustion Desulfurization Slag

Cheng

Hou

Han

et al. 2018

Advances in Materials Science and Engineering

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Circulating fluidized bed combustion (CFBC) desulfurization slag is a waste residue discharged from coal power plants. In this article, expansion characteristics and compressive strength of mortars containing CFBC desulfurization slag were evaluated, subjected to mechanical grinding time, the amount of additive, and chemical activation. Correlations between the linear expansion rate and compressive strength were investigated. e hydration products of cement-slag cementitious system were analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). e results show that mechanical grinding can increase both the expansion and compressive strength of mortars containing CFBC desulfurization slag, and the compressive strength and linear expansion can develop in coordination. While increasing the amount of the fine desulfurization slag, the linear expansion rate increases, and the compressive strength reaches to the maximum when the amount is 30%. Moderate sodium sulfate as an activator can both promote the compressive strength and increase the expansion of mortars.

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Effect of circulating fluidized bed combustion ash on the properties of roller compacted concrete

Cited by 89 publications

References 24 publications

Utilization of Circulating Fluidized Bed Fly Ash as Pozzolanic Material

Utilization of Circulating Fluidized Bed Fly Ash as Pozzolanic Material

Recent durability studies on concrete structure

Research on the Expansion Characteristics and Compressive Strength of Mortars Containing Circulating Fluidized Bed Combustion Desulfurization Slag

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