[01] Saad Issa Sarsam, Department of Civil Engineering, College of Engineering, Univers.

This paper presents a computerized method for asphalt concrete job-mix formula design; the preparation of overall gradation of aggregates for mix design is considered as an essential step in the design of asphalt concrete mixture. The target gradation should be dense, uniform, and should not go for one extreme boundary to another or move along one of the boundaries. On the other hand, the maximum size of aggregates (start point of the gradation curve) and the percent filler (end of the gradation curve) are fixed for each type of asphalt concrete mix. The parabola fit using least square method was adopted in this paper; it cares for job mix formula mathematical equation smoothing. The developed program uses parabola fit method to find all possible equations that combines the various material gradations as per the specification requirements, the optimization process will select and print the best six formulas (eq. 1 to eq.6) ascended according to the sum of errors squares. Decision can be made by the user, and given to the computer to choose one of the six equations after considering the economic issue. For several months with every day execution of the program, it proved that it is efficient and quick enough to be used in such mix design.

Asphalt Concrete, Design, Job-Mix Formula, Least Square, Optimization

[01] Irick P. (1963) “Application of general curve fitting procedure to AASHO road test data” HRB, Highway research record No. 42, USA. [02] Sarsam S. (2013) “Stepwise Optimization Modeling of Asphalt Concrete Mix Design” Research Journal of Computation and Mathematics, RJCM 2013, 1(2): P (28-32); Sciknow Publications Ltd. USA. [03] Sarsam S. (1997) “The design of asphaltic concrete mix using a mathematical model” Journal of Engineering and Technology Vol. 16 No. 3, University of technology, Baghdad, Iraq. [04] Sarsam S. (2012) “Computerized Optimization of Asphalt Concrete Mix Design” Proceedings, International Conference on Management Sciences and Information Technology (MSIT 2012) Changsha, China, July 1-2, 2012 [05] SCRB (2004) “Standard specification for roads and bridges” Ministry of Housing and construction, Iraq [06] Yeaman J. (1970) “The design of asphaltic concrete using mathematical models and linear programming techniques” Proceeding, ARRB – Vol.5 Part 5 Australia.