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Influence of pretreatment process on the properties of phosphogypsum-based composite binders



Title: Influence of pretreatment process on the properties of phosphogypsum-based composite binders
Author(s): J.K. Yang, T.Y. Ren, J. Zhu, Y.L. Li, N. Ye, X.F. Zhu and J.W. Liu
Paper category : conference
Book title: International RILEM Conference on Advances in Construction Materials Through Science and Engineering
Editor(s): Christopher Leung and K.T. WAN
ISBN: 978-2-35158-116-2
e-ISBN: 978-2-35158-117-9
Publisher: RILEM Publications SARL
Publication year: 2011
Pages: 868 - 876
Total Pages: 9
Nb references: 11
Language: English


Abstract: Phosphogypsum-based composite binder (PGCB) is made from phosphogypsum (PG), fly ash, lime, Portland cement, and chemical activator. The influence of pretreated PG on the properties of PGCB was investigated. Three types of pretreatment processes were conducted on PG, i.e. autoclaving at 180 oC for 4 hours, calcining at 700 oC for 2 hours, and autoclaving at 120 oC for 1.5 hours followed by calcining at 700 oC for 2 hours. The crystalline phases could be transformed and the impurities of original PG could be effectively purified by the pretreatment process. Weight loss after static water attack (WLSW) and weight loss after flowing water attack (WLFW) of the PGCB mortars were studied to evaluate their water resistance. Effects of the content of pretreated PG on the properties of the PGCB were investigated. An optimum proportion, 80% of the pretreated PG content, was initially proposed. At the optimum proportion, the compressive strength of PGCB mortars after the tests of WLSW and WLFW could keep more than 30 MPa, and WLSW and WLFW were lower than 0.5% and 2% respectively. Generally PGCB mortars showed good water resistance after PG was pretreated with a suitable process.


Online publication: 2011-10-31
Publication type : full_text
Public price (Euros): 0.00