Improved Sub-Grade or Pervious Back Fill Any course or courses of select or improved material between the foundation soil and the sub base is usually referred to as the improved sub grade. The improved sub grade can be made up of two or more courses of different quality materials aggregate. Improved Sub-Grade or Pervious Back Fill Any course or courses of select or improved material between the foundation soil and the sub base is usually referred to as the improved sub grade. The improved sub grade can be made up of two or more courses of different quality materials aggregate.
Better Way produces different types of improved sub-grade and capillary as per the standards of ASHTO.