MASTIC COMPOSITION AND METHOD OF PREPARING SAME

摘要

A mastic product comprising bitumen, filler and aggregate is prepared by introducing into a mixer aggregate in an unheated and undried condition and with a water content controlled to be at least about 3 % by weight by reference to the total mastic composition, adding all the required bitumen at elevated temperature while the mixer is in operation, subsequently adding the required filler in an unheated condition and continuing mixing operation whilst allowing the mixture to cool, to produce a granular product. The moisture content is controlled so as to provide sufficient "lubrication" for which a minimum input of about 3 % is appropriate, and the maximum water input should preferably not exceed about 7 % because of potential problems at the point of use. Water may be added to, or drained from, the aggregate before or after it is introduced into the mixer in order to maintain a designed mean water content in the final product of about 3.5 % and typically a maximum of 4 %.