Quality control method of compaction degree of natural clay mineral crushed stone water shielding material

摘要

PROBLEM TO BE SOLVED: To provide a low water-permeability crushed stone material of a natural clay mineral, which has uniform quality and is inexpensive and with which water can be shut off permanently, and to provide a method for measuring density of the same.SOLUTION: In a low water-permeability crushed stone material of a natural clay mineral, in crushed stones formed from the natural clay material containing smectite and having grain diameters of 25 mm or less, natural moisture content ratio is adjusted within a range where an upper limit value is set to the optimum moisture ratio or less and a lower limit value is set to the optimum moisture ratio -10% or more, or is adjusted within a range where a coefficient of water permeability, subjected to moisture content ratio adjustment, is 1×10cm/sec or less. Further, density of the crushed stones formed from the natural clay material containing the smectite and having the grain diameters of 25 mm or less is measured with a handy typed bearing capacity tester (CASPOL).