<p>Reference(s):</p> <p>ACI Committee 506 (1995)</p> <p>ACI Committee 506 (1994)</p> <p>Hanskat (2011)</p> <p>Kutschke et al. (2007)</p> <p>&nbsp;</p> <p><strong>Method Summary</strong></p> <p>The purpose of measuring the compressive strength of concrete used in shotcrete is to ensure that it will withstand the designed load without failure. Test panels are shot before an application is started on the rock slope. Six cores are cut from the test panels: three with rebar reinforcement and three without reinforcement. The uniaxial compressive strength is measured for each core.</p> <p><strong>Accuracy and Precision</strong></p> <p>Test panels are created from the same batch of shotcrete to be used in the reinforcement structure. The accuracy and precision of calculating compressive strength are based on the equipment and operator. The accuracy and repeatability of compressive tests are why it has become so widely adopted as a quality control method.</p> <p><strong>Adequacy of Coverage</strong></p> <p>Test panels are created for each batch and each nozzleman who will be working on the project.</p> <p><strong>Implementation Requirements</strong></p> <p>There are no requirements other than the necessary equipment to measure compressive strength.</p> <p><strong>General Comments</strong></p> <p>To pass the compressive strength requirement, the average of three cores must be greater than 85% of the specified compressive strength and not one sample can be less than 75%.</p>