Trial of high early-strength grout-hardening accelerating admixture for cable bolts

Authors: Lane, M; McInnes, M Download Paper Open access courtesy of:

DOI https://doi.org/10.36487/ACG_repo/2325_43

Cite As:
Lane, M & McInnes, M 2023, 'Trial of high early-strength grout-hardening accelerating admixture for cable bolts', in J Wesseloo (ed.), Ground Support 2023: Proceedings of the 10th International Conference on Ground Support in Mining, Australian Centre for Geomechanics, Perth, pp. 635-644, https://doi.org/10.36487/ACG_repo/2325_43



Abstract:
A specialised hardening accelerating admixturefor addition to the low-heat cement mix for cable bolt grouting used at Nova Operation, SikaRapid-700 L (Additive 1) and SikaRapid-440P (no longer available [Additive 2]), was trialled to improve the early strength properties of the cable bolt grout. These products were trialled to reduce installation turnaround times for grouted cable bolts and improve long-term grout strengths. The hardening accelerating admixture promotes early strength development while positively influencing final strength. The properties of the hardening accelerators trialled allow for bringing cable bolts into service sooner through high early strength gain with no negative effects on final strength of the grout. This paper outlines the practical aspects for the application of a high early-strength grout for cable bolting. Testing included pull testing of cable bolts at set time intervals to establish cable bolt capacity over time and uniaxial compressive strength testing of grout to establish a curing curve to estimate the grout strength over time.

Keywords: cable bolting, grout, high early strength, uniaxial compressive strength testing, pull testing

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