Effects of accelerator–water reducer admixture on performance of cemented paste backfill. (10th May 2020)

• Record Type: Journal Article
• Authors: Liu, Yin; Li, Hao; Wang, Kai; Wu, Haifeng; Cui, Boqiang
• Is Part Of: Construction & building materials. Volume 242(2020)
• Publication Date: 2020-05-10
• Subjects: AFt ettringite -- CPB cemented paste backfill -- PCS polycarboxylate-based superplasticizer -- NS naphthalene-based superplasticizer -- UCS uniaxial compressive strength -- XRD X-ray diffraction -- SEM scanning electron microscopy -- EDS energy-dispersive X-ray spectroscopy; CPB -- Accelerator -- Water reducer ettringite -- Calcium-silicate-hydrate; Building materials -- Periodicals; 624.18
• DOI: 10.1016/j.conbuildmat.2020.118187
• Languages: English
• ISSNs: 0950-0618

Abstract

Highlights: We evaluate effects of accelerator-water reducer admixture on performance of CPB. Na2 SO4 is mixed with polycarboxylate (PCS) or naphthalene (NS). Fluidity, water-reduction rate, setting time, adsorption, and UCS are measured. 0.5% Na2 SO4 + 0.2% PCS or 0.5% Na2 SO4 + 0.5% NS improve CPB performance. Needle-like material is formed in early stage and white fibrous one in later stage. Abstract: In this study, the effects of using an accelerator-water reducer admixture on the working performance of cemented paste backfill (CPB) were studied experimentally. Specifically, Na2 SO4 was mixed with one of two different water reducers, namely, a polycarboxylate-based superplasticizer (PCS) and a naphthalene-based superplasticizer (NS). The effects of complex mixing were evaluated through macroscopic and microscopic tests. The results showed that, using an admixture of 0.5% Na2 SO4 with 0.2% PCS or 0.5% Na2 SO4 with 0.5% NS for preparing the CPB results in low cement consumption, good fluidity, short setting time, high water-reduction rate, and high UCS.