Synergistic effect of recovering hardened cement powder and aluminum sulfate alkali-free liquid accelerator for enhancing the hydration and hardening of cement paste

Wu, Zhihong; Huang, Wang; Zhang, Wan; Liu, Jiayuan; Zhou, Huafeng; Qiu, Junlong

doi:10.1016/j.jobe.2023.106348

Cited by 8 publications

(1 citation statement)

References 30 publications

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“…With the SDTQ 600 TA thermogravimetric analyzer (TGA), a thermogravimetric test was performed at a heating rate of 10 °C/min in a nitrogen atmosphere, and the number of hydrated products generated was calculated. The contents of CH and CC in samples were calculated according to formulae and , respectively: where M CH is the content of CH in the sample, M CC is the content of CC in the sample, M H is the weight loss of the sample within 400–500 °C and M C is the weight loss of the sample within 550–800 °C.…”

Section: Materials and Experimentsmentioning

confidence: 99%

Utilizing the Adsorbability of Pseudoboehmite for Tailoring the Stability of an Aluminum Sulfate Alkali-free Accelerator for Shotcrete

Huang,

Wu,

et al. 2024

Langmuir

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Shotcrete is widely used in tunnels, bridges, culverts, and other large-scale projects. The accelerator is an additive employed to expedite the setting time of shotcrete. Previous research primarily concentrated on enhancing the early strength of accelerators, whereas their long-term stability has been inadequately investigated. In this study, pseudoboehmite (PB) and amorphous aluminum hydroxide (AAH) were incorporated into the accelerator to enhance its stability over a period of 90 days without any signs of crystallization or delamination. Furthermore, the accelerator exhibited an initial setting time of 170 s, a final setting time of 550 s, and a compressive strength of 11.58 MPa after 1 day. The mechanism of effects was studied by isothermal calorimetry, FTIR, XRD, TG-DTG, and SEM analysis. The enhancement in stability is attributed to the distinctive adsorption and thixotropic properties of PB, which facilitate the formation of an electrical double-layer structure in acidic solutions. The expedited setting and hardening are primarily due to the equilibrium between Al 3+ , SO 4 2− , and Ca 2+ ions, which accelerates the hydration process of cement. This research offers a methodology for developing a high-performance, alkali-free liquid accelerator.

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Section: Materials and Experimentsmentioning

confidence: 99%