I normally provide Limestone quarry run material (0.1 to 500kg) behind blockwork quay walls and use an angle of internal friction of 40 deg. to calculate the earth pressures. But I have come across design calculations where 45 deg. is being used. It does make a lot of difference when we use the higher value in that the cross-sections reduce.
I have not come across any literature where the use of 45 deg. is recommended for quarry run material. There is a reference to quarry run material in the Design of Small Dams (USBR), but this is again for much smaller sizes and high confining pressures. Can someone guide me to some research or literature review.