The Los Angels abrasion value requirement for coarse aggregates used in water bound macadam for the base course is: Los Angeles test is commonly used to evaluate the hardness of aggregates. The test has more acceptability because the resistance to abrasion and impact is determined simultaneously. Depending upon the value, the suitability of aggregates for different road constructions can be judged as per IRC specifications as given below:
SI.
Type of Pavement
Aggregate impact Max. Permissible abrasion value in %
1.
Water bound macadam(WBM) sub-base course
50
2.
Cement concrete base course
45
3.
(i) WBM base course with bituminous surfacing(ii) WBM base course with built up spray grout coarse aggregate.