Development of a New Type of Alkali-Free Liquid Accelerator for Wet Shotcrete in Coal Mine and Its Engineering Application

<table class="table-group" id="tab2"><tr><td><table class="table"><tr><td class="thead-hr" colspan="5"><hr/></td></tr><tr class="thead"><td align="left" rowspan="3">Product rating</td><td align="center" colspan="4">Test items</td></tr><tr class="thead"><td align="center" colspan="2">Cement paste</td><td align="center" colspan="2">Cement mortar</td></tr><tr class="thead"><td align="center">Initial setting time/min</td><td align="center">Final setting time/min</td><td align="center">Compressive strength of one day/MPa</td><td align="center">Compressive strength ratio of 28 days/%</td></tr><tr><td class="thead-hr" colspan="5"><hr/></td></tr><tr><td align="left">First grade</td><td align="center">≤3</td><td align="center">≤8</td><td align="center">≥7.0</td><td align="center">≥75</td></tr><tr><td align="left">Qualified product</td><td align="center">≤5</td><td align="center">≤12</td><td align="center">≥6.0</td><td align="center">≥70</td></tr><tr class="table-tr"><td colspan="5"><hr class="tbody-hr"/></td></tr></table></td></tr></table>

Performance requirements of cement paste and cement mortar mixing accelerator.

Advances in Materials Science and Engineering

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Table 2

Table 2: Development of a New Type of Alkali-Free Liquid Accelerator for Wet Shotcrete in Coal Mine and Its Engineering Application 