This is the rock we're using for Crushed Base and Surfacing (AC20 and AC14). It originates from limestone. Its strength is around 140kN to 150kN, slightly sound rock for these works.
The only draw backs i can imagine is its non-homogeneity nature. A lot of unsuitable/foreign materials were found within this rock mass, as can be seen in this picture there are some soil and dirt inside it.
But it is good if sampled well.
