Expansion Properties of Cemented Foam Backfill Utilizing Coal Gangue and Fly Ash
نویسندگان
چکیده
The cemented backfill (CB) utilizing coal gangue (CG) and fly ash (FA) is widely applied in mines. However, the bleeding shrinkage of CB leads to insufficient contact with surrounding rock, which not beneficial for controlling roof subsidence even stope stability. Herein, a foam (CFB) formulation demonstrated, employing hydrogen dioxide (H2O2) as chemical foaming agent. cement FA show noticeable inhibiting effects on volume expansion due network formed by their hydrates. Moderately lower cement, FA, solid concentration are improve increment prolong expanding duration. A coefficient (k) proposed theory evaluate efficiency. kem values, determined evolution experiments CFB slurries, provide calculation basis needed dosage H2O2 solution targeting specific increment. specimens ratios 21%~103% densities 994~592 kg/cm3 were prepared, an actual 52.40 cm3/g uniaxial compressive strength (UCS) 0.32~0.55 MPa. mass was 1.9%~11.3% 0.29%~1.67% total materials weight. UCS decline compared attributed rich pores observed CT carbonation indicated X-ray diffraction (XRD).
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ژورنال
عنوان ژورنال: Minerals
سال: 2022
ISSN: ['2075-163X']
DOI: https://doi.org/10.3390/min12060763