supply of materials ( stone ballast ) for balance work of extension of govt . , craftsman instructor training institute at distt sultanpur supply of materials ( stone ballast ) for balance work of extension of govt . , craftsman instructor training institute at distt . sultanpur , supply of 20-40mm guage approved stone ballast from stone chips or stone ballast for cement concrete ( plain or reinforced ) shall be hard , of uniform and fine texture . free form faults or planes of weakness and free from weathered faces . the ballast or chips must be free from loam , clay or any surface coating , free from organic matter or other impurities and screened , free of dust . stone of black and hard variety as is generally available from quarries in shankargarh areas will be normally used . stone aggregates from other sources may also be used provided the same is found suitable in the opinion of the engineer-in-charge . the opinion of engineer-in-charge must be recorded in writing . the ballast or chips shall be obtained by breaking from large blocks and must be more or less cubicle in shape stone grit grading shall be in conformity with the requirements laid down in the indian standards specification . , add gst as applicable