CRIME-PREVENTIVE GRAVEL, AND METHOD OF PRODUCING CRIME-PREVENTIVE GRAVEL

摘要

PROBLEM TO BE SOLVED: To provide crime-preventive gravel which can exert crime-preventive effect without monitoring work, and to provide a method of producing the crime-preventive gravel.;SOLUTION: According to the method, a stone-shaped original material made of glass as a raw material is formed, and a corner protruding from an outer surface 2 of the original material is removed in a corner cutting step SG8, followed by setting a mean particle size R1 of the crime-preventive gravel 1 in the range of 13 to 30 mm. Then, a number of bubbles are formed in each piece of the crime-preventive gravel 1 so as to generate large sound when brought into sliding contact with each other. Further, the outer surface 2 of the crime-preventive gravel 1 is coated with colorants, and therefore a plurality of types of crime-preventive gravel 1 which are different in color from each other, are provided.;COPYRIGHT: (C)2005,JPO&NCIPI