The relative density of geologically aged British Fine and fine-medium sands

Values of relative density (Dr) have been measured on 20 samples of uncemented, virtually matrix-free, fine and fine-medium quartzose sands ranging in age from Recent to Jurassic. For all except Recent and younger Pleistocene sands, which were impregnated in situ, the in situ dry density (ρd) was measured on intact, block samples. A single method was used for ρd min (Kolbuszewski's tilting method) and three methods for ρd max: namely the vibrating hammer procedures of Kolbuszewski, B. S. 1377 Test 14 and slow pouring. A general trend of increasing Dr with geological age was given by all the methods used for determining ρd max. Even with the Kolbuszewski method, values of Dr > 100% were obtained on some of the sands: a maximum of 112 % being recorded on the Grantham Sand of Jurassic age. Values of Dr using the B.S. 1377 procedure ranged between 23 and 57 % for the Recent and Pleistocene sands and between 90 and 122 % for the Tertiary and Mesozoic sands. The ease of the slow pouring method for ρd max recommends it as a potentially useful diagnostic test to determine the degree of locking in geologically aged sands