Job Mix Formulation for Bituminous Concrete Grade II Using C# Programming

Abstract

Bituminous Concrete mix design is a complex process and different methods are proposed by a number of researchers. Marshall’s method of mix design is one such process, which became very popular among the practitioners in India and elsewhere. SUPERPAVE method of mix design which takes into account climatic and traffic factors for aggregate and binder selection. It has gained its prominence and is observed to be superior to any other well-known mix design processes. Aggregate gradation adopted for the mix design plays a crucial role in the performance of the mix. Many researchers have developed mechanisms to work out Job Mix Formulations (JMF) so as to reach the appropriate aggregate mix in the field.
The analytical phase of JMF deals with the method of blending of aggregates from the identified stockpiles in order to fulfill the requirements of gradation as specified by agencies for a given layer of flexible pavements. Methods proposed for aggregate blending includes the graphical methods, trial and error method and optimization techniques. The aim of these techniques is two-fold; the first is to optimize the cost involved in blending from the known unit cost of individual stockpiles; and the other is to fulfill the gradation recommendations of the local agencies and parameters suggested in other methods. In this research, an attempt has been made to develop C# (C-Sharp) application in .NET framework using the sequential search technique to work out the best blend of aggregate particles by ensuring the requirements mentioned in MoRTH’s (Ministry of Road Transport & Highways, India) recommended practice. Bailey’s method and the maximum density line have been recommended in 0.45 power chart and incorporating optimization criteria. Grade II bituminous concrete has been chosen for the research. It was clearly observed that the fine aggregate fraction in the stockpiles influences the final Job Mix Formulation. The devleloped tool can accommodate up to 5 stockpiles. It was also observed that the Bailey’s requirements are more stringent when compared with MoRTH requirements as far as JMF is considered. The developed tool is capable of generating the blends with Recycled Asphalt Pavement (RAP) aggregate blends.