Subgrades and Subbases for Slabs| Concrete Construction,
Nov 22, 2017· Although the subbase is not mandatory, it serves as a work platform for construction of the slab and a cushion for more uniform support of the slab. Most road base material approved by the local DOT is suitable for the subbase. “We use 6 to 8 inches of crusher run,” says Steve Lloyd, Lloyd Concrete Services, Forest, Va.gravel under concrete slab? is it absolutely required,,so, I have a post-frame shed, 12x16. there are posts at 6' on the short sides and every 4' on the long side. posts are set ~18" below grade, on a 2" cap of cement over a few inches of well compacted gravel, holes were all about 27" or so, 2x6 girder runs level at the top (very level all the way around) around base, ok, so, basically I have ~5.5" to grade from bottom of 2x6 girder to top of,Clay,Cement,Slag,Coke,Clinker Used Double Roller Crusher,,Clay,Cement,Slag,Coke,Clinker Used Double Roller Crusher,Double Roll Crusher For Sale , Find Complete Details about Clay,Cement,Slag,Coke,Clinker Used Double Roller Crusher,Double Roll Crusher For Sale,Small Stone Crusher Machine,Double Roller Crusher,Used Roll Crusher from Crusher Supplier or Manufacturer-Zhengzhou Huahong Machinery Equipment Co., Ltd.