posted 9 years ago
A primary function of a rubble trench foundation is it's ability to act a drain for any water. Without knowing exactly what asphalt millings are like, but knowing what asphalt is like, I would be concerned that the material would not remain "loose" enough to function as a drain. Over time would it compact into one large wad of asphalt? It seems with rubble trench, the key is have large enough material to promote fast drainage, but small enough to compact effectively, eliminating settling. I have only done one rubble trench, so I am by no means an expert.