Ranking the performance of aggregates using CEN test results

BS specifications are in common usage in the Irish aggregate industry. After CEN harmonisation, the aggregate abrasion value (AAV) and the polished stone value (PSV) tests will remain unchanged and continue to be used. There will be modifications to the flakiness index, particle density, sand equivalent and methylene blue test procedures. The Micro-Deval (MDE), Los Angeles (LA) abrasion, Sonnenbrand, and Delta ring and ball tests will be new. The aggregate crushing value (ACV), aggregate impact value (AIV) and ten per cent fines value (TFV) will be discontinued. For quarry production, it is likely that the 28 mm stockpile will be replaced by a 31.5 mm stockpile. To rank the performances of aggregates using the CEN tests, four to six test results were used to make comparisons on a statistical basis. Both the parametric Tukey HSD test and the nonparametric Mann-Whitney U test were used in the analyses. Correlations were established between BS and CEN tests for flakiness index. The CEN index is lower. A large correlation (r = 0.90) was established between the LA and the ACV test results. A correlation (r = 0.81) was also established between the MDE and the AA V results. For igneous rocks, water absorption may be an indicator of performance in the MDE test. Stepwise regression procedures were employed to choose a suitable set of predictors for the LA results. Limestone with a higher silica content had a greater resistance to fragmentation. The hematite mineral seemed to have a dominant effect on the outcome of the methylene blue test.