On the interaction of Class C fly ash with Portland cement–calcium sulfoaluminate cement binder

In order to reduce the CO2 emission and cost of binders used in cemented paste backfill (CPB) technology, new blended binders with a large amount of fly ash (FA) were fabricated. Different doses of quicklime and calcium sulfoaluminate cement (CṠA) were used as mineral accelerators to improve the early workability of CPB. The effects of CṠA and quicklime on flowability, compressive strength, pore structure, hydration heat, and hydration evolution were investigated experimentally. The results showed that the addition of quicklime and CṠA reduced the spread diameter of the fresh backfill and improved the mechanical performance of the hardened CPB. With increasing quicklime and CṠA, the cumulative hydration heat of the blended binder distinctly increased in the first 6 h. CṠA improved the initial hydration by increasing the reactivity, and quicklime increased the hydration rate by activating FA. The blended binder (15% quicklime + 10% CṠA) with the lowest CO2 emission and cost had potential application in filling technology.

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Influence of fly ash on the hydration of calcium sulfoaluminate cement

Cement and Concrete Research ◽

10.1016/j.cemconres.2017.02.030 ◽

2017 ◽

Vol 95 ◽

pp. 152-163 ◽

Cited By ~ 61

Author(s):

Lukas H.J. Martin ◽

Frank Winnefeld ◽

Elsa Tschopp ◽

Christian J. Müller ◽

Barbara Lothenbach

Keyword(s):

Fly Ash ◽

Calcium Sulfoaluminate Cement ◽

Calcium Sulfoaluminate

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Study of Alite-Calcium Sulfoaluminate Cement Produced from a High-Alumina Fly Ash

ACI Materials Journal ◽

10.14359/51734199 ◽

2022 ◽

Vol 119 (1) ◽

Author(s):

Tristana Y. Duvallet ◽

Manuelle Paraschiv ◽

Anne E. Oberlink ◽

Robert B. Jewell ◽

Thomas L. Robl

Keyword(s):

Fly Ash ◽

High Alumina ◽

Calcium Sulfoaluminate Cement ◽

Calcium Sulfoaluminate

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Influence of Fly Ash on Mechanical Properties and Hydration of Calcium Sulfoaluminate-Activated Supersulfated Cement

Materials ◽

10.3390/ma13112514 ◽

2020 ◽

Vol 13 (11) ◽

pp. 2514

Author(s):

Zhengning Sun ◽

Jian Zhou ◽

Qiulin Qi ◽

Hui Li ◽

Na Zhang ◽

...

Keyword(s):

Mechanical Properties ◽

Fly Ash ◽

Flexural Strength ◽

Heat Evolution ◽

Hydration Products ◽

X Ray Diffraction ◽

Calcium Sulfoaluminate Cement ◽

Calcium Sulfoaluminate ◽

Granulated Blast Furnace Slag ◽

Compressive And Flexural Strengths

This paper aimed to report the effects of fly ash (FA) on the mechanical properties and hydration of calcium sulfoaluminate-activated supersulfated cement (CSA-SSC). The CSA-SSC comprises of 80% granulated blast furnace slag (GBFS), 15% anhydrite, and 5% high-belite calcium sulfoaluminate cement (HB-CSA) clinker. The hydration products of CSA-SSC with or without FA were investigated by X-ray diffraction and thermogravimetric analysis. The experimental results indicated that the addition of FA by 10% to 30% resulted in a decrease in the rate of heat evolution and total heat evolution of CSA-SSC. As the content of FA was increased in the CSA-SSC system, the compressive and flexural strengths of the CSA-SSC with FA after 1 day of hydration were decreased. After 7 days of hydration, the compressive and flexural strength of CSA-SSC mixed with 10 wt.% and 20 wt.% of FA rapidly increased and exceeded that of ordinary Portland cement (OPC), especially the flexural strength. Moreover, the compressive strength of CSA-SSC mixed with 30 wt.% of FA after 90 days of hydration was close to that of OPC, and flexural strength of CSA-SSC mixed with 30 wt.% of FA after 7 days of hydration was close to that of OPC. The hydration products of the CSA-SSC and CSA-SSC mixed with FA were mainly ettringite and calcium silicate hydrate (C-S-H).

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Influence of Cementitious System Composition on the Retarding Effects of Borax and Zinc Oxide

Materials ◽

10.3390/ma12152340 ◽

2019 ◽

Vol 12 (15) ◽

pp. 2340

Author(s):

Feraidon F. Ataie

Keyword(s):

Zinc Oxide ◽

Portland Cement ◽

Heat Of Hydration ◽

Hydration Products ◽

Calcium Sulfoaluminate Cement ◽

Calcium Sulfoaluminate ◽

System Composition ◽

Cementitious System ◽

Cementitious Systems ◽

Aluminate Cement

This research investigated the retarding impact of zinc oxide (ZnO) and borax (Na2[B4O5(OH)4]·8H2O) on hydration of Portland cement, calcium aluminate cement (CAC), and calcium sulfoaluminate cement (CSA). Heat of hydration of cement paste samples with and without ZnO and borax was used to measure the influence of ZnO and borax on the set time of these cementitious systems. It was found that both ZnO and borax can retard the set time of Portland cement systems; however, ZnO was shown to be a stronger set time retarder than borax for these systems. ZnO did not show any retarding impact on CAC and CSA systems while addition of borax in these systems prolonged the set time. It was concluded that ZnO does not poison the nucleation and/or growth of CSA and CAC hydration products. We suggest that borax retards the cement set time by suppressing the dissolution of cement phases.

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Evaluation of Shrinkage Resulted Cracking of High Strength Calcium Sulfoaluminate Cement Concrete with Impact of Internal Curing

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.629-630.144 ◽

2014 ◽

Vol 629-630 ◽

pp. 144-149

Author(s):

Yi Ming Luosun ◽

Jun Zhang ◽

Yuan Gao

Keyword(s):

Portland Cement ◽

Autogenous Shrinkage ◽

High Strength ◽

Internal Curing ◽

Ring Test ◽

Portland Cement Concrete ◽

Cement Concrete ◽

Calcium Sulfoaluminate Cement ◽

Calcium Sulfoaluminate ◽

Cracking Performance

In this paper, restrained ring test and shrinkage test are carried on three kinds of concrete—high-strength portland cement concrete, high-strength calcium sulfoaluminate cement concrete and high-strength calcium sulfoaluminate cement concrete with internal curing in order to evaluate the shrinkage induced cracking performance of the concretes. The experimental results show that calcium sulfoaluminate cement concrete exhibits lower shrinkage caused by surface drying comparing to portland cement concrete. Internal curing can eliminate most of the autogenous shrinkage of concrete. In the ring test, the latter two concrete did not crack during the whole test history—42 days, while high-strength portland cement concrete cracked at the 13th day after casting. High strength calcium sulfoaluminate cement concrete exhibits better anti-cracking ability than the high strength portland cement concrete with the same strength grade.

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