Methods and materials for the construction of concrete safety barriers and the manufacture of precast units.Cross References:BS 12BS 146BS 499BS 729BS 877BS 882BS 970:Part 1BS 1014BS 1047BS 1881BS 3797BS 4449BS 4483BS 5075:Part 1BS 5075:Part 2BS 5328BS 5931BS 6779BS 8110:Part 1