A platform for research: civil engineering, architecture and urbanism
A platform for research: civil engineering, architecture and urbanism
Influence of the calcination temperature of phosphogypsum on the performance of supersulfated cements
Highlights The use of phosphogypsum in SSC provided similar results to conventional sources. Higher formation of ettringite was not related to higher compressive strength. Higher formation of secondary gypsum was related to lower compressive strength.
Abstract Supersulfated cements (SSCs) are binders comprising mostly of granulated blast-furnace slag and calcium sulfate. In this study, phosphogypsum was used as source of calcium sulfate and the influence of its solubility (availability) on the properties of SSC was investigated. Mixtures were tested using 10 and 20% phosphogypsum calcined at either 350 or 650 °C, which were more or less soluble, respectively. The largest ettringite formations were verified in samples with greater calcium sulfate availability (20%, calcined at 350 °C), however, the highest compressive strength was not reported at this condition. The calcination temperature of 350 °C was shown to be only adequate for cements with lower calcium sulfate content. In mixtures with 20% calcium sulfate the compressive strength was low and related to the intense formation of secondary gypsum. In this study, the unavailability of calcium sulfate was preferable to high availability. The conversion of ettringite into monosulfate did not unduly influence the behavior of the SSCs. .
Influence of the calcination temperature of phosphogypsum on the performance of supersulfated cements
Highlights The use of phosphogypsum in SSC provided similar results to conventional sources. Higher formation of ettringite was not related to higher compressive strength. Higher formation of secondary gypsum was related to lower compressive strength.
Abstract Supersulfated cements (SSCs) are binders comprising mostly of granulated blast-furnace slag and calcium sulfate. In this study, phosphogypsum was used as source of calcium sulfate and the influence of its solubility (availability) on the properties of SSC was investigated. Mixtures were tested using 10 and 20% phosphogypsum calcined at either 350 or 650 °C, which were more or less soluble, respectively. The largest ettringite formations were verified in samples with greater calcium sulfate availability (20%, calcined at 350 °C), however, the highest compressive strength was not reported at this condition. The calcination temperature of 350 °C was shown to be only adequate for cements with lower calcium sulfate content. In mixtures with 20% calcium sulfate the compressive strength was low and related to the intense formation of secondary gypsum. In this study, the unavailability of calcium sulfate was preferable to high availability. The conversion of ettringite into monosulfate did not unduly influence the behavior of the SSCs. .
Influence of the calcination temperature of phosphogypsum on the performance of supersulfated cements
Gracioli, B. (author) / Angulski da Luz, C. (author) / Beutler, C.S. (author) / Pereira Filho, J.I. (author) / Frare, A. (author) / Rocha, J.C. (author) / Cheriaf, M. (author) / Hooton, R.D. (author)
2020-06-12
Article (Journal)
Electronic Resource
English
Influence of curing temperature on the process of hydration of supersulfated cements at early age
| Online Contents | 2015