COMPUTER AIDED DESIGN OF BITUMINOUS MIXES FOR PAVEMENTS

Abstract

Bituminous road construction is very common in India. The desirable properties of a bituminous mix are: stability, density, durability, flexibility, resistance to skidding and workability. The properties of bituminous mix depend on its ingredients. So to make an efficient bituminous mix, ingredients should be in proper proportion and a suitable mix design method should be used. Different types of construction methods of the flexible pavement require materials of definite grading. Sometimes materials of required grading are not available at site, and two or more materials are mixed to obtain material of required grading. To decide the proportion of materials, Rothfutch's method is most commonly used. This method involves a lot of interpolation and is also time consuming. After obtaining the material of required grading, a bituminous mix for that type of construction method is prepared. For the purpose of bituminous mix design Marshall method is generally used. It also involves tedious calculations, interpolations and approximation. To avoid above problems, a generalized and user friendly package for bituminous mix design has been developed. Package entitled "BITU-MIX' 2001", written in "C" language, can design the bituminous mix based on Marshall method. This package also carries out proportioning by Rothfutch's method. It also includes the features of interactive data entry and displays warning massages in case of wrong entry. It displays all graphs of proportioning and Marshall parameters. This has been validated by solving a problem.