Experimental study on the effect of fly ash content in cemented paste backfill on its anti-sulfate erosion. Issue 12 (25th September 2020)

• Record Type: Journal Article
• Authors: Cui, Boqiang; Liu, Yin; Feng, Guorui; Bai, Jinwen; Du, Xianjie; Wang, Changxiang; Wang, Huaifa
• Is Part Of: International journal of green energy. Volume 17:Issue 12(2020)
• Page Start: 730
• Page End: 741
• Publication Date: 2020-09-25
• Subjects: Cemented paste backfill -- fly ash content -- sulfate erosion -- uniaxial compression Strength -- microscopic analysis -- cracking mechanism -- anti-sulfate erosion; Power resources -- Research -- Periodicals; Energy industries -- Periodicals; Energy development -- Periodicals; 333.79
• DOI: 10.1080/15435075.2020.1791877
• Languages: English
• ISSNs: 1543-5075

Abstract

ABSTRACT: In order to study the effect of fly ash content in cemented paste backfill (CPB) on its anti-sulfate erosion, the apparent phenomenon, strength development, and hydration products change the law of CPB with different fly ash content under long-term soaking of 5% sodium sulfate solution were studied by the macrotest and microanalysis, in addition, the mechanism of CPB anti-sulfate attack was analyzed by combining with a scanning electron microscope (SEM). The results indicated that the effect of sulfate environment on the strength of fly ash cemented paste backfill (FCPB) was mainly determined by the hydration products in the FCPB at different soaking times. In the early soaking stage, the formation of ettringite (AFt) in FCPB could improve its compactness, which was conducive to improving the strength of FCPB. In the late soaking stage, there were ettringite-type erosion damage and gypsum erosion-type damage internal of the FCPB with low content fly ash, resulting in microfracture, cracking of the FCPB, and reducing the strength. CPB with an appropriate content of fly ash could improve the internal structure of the FCPB to achieve the purpose of anti-sulfate erosion.