INTERNATIONAL JOURNAL OF OPTIMIZATION IN CIVIL ENGINEERING Int. J. Optim. Civil Eng., 2015; 5(2):189-203 OPTIMIZATION OF RC FRAMES BY AN IMPROVED ARTIFICIAL BEE COLONY ALGORITHM Ch. Gheyratmand, S. Gholizadeh *, † and B. Vababzadeh Department of Civil Engineering, Urmia University, Urmia, Iran ABSTRACT A new meta-heuristic algorithm is proposed for optimal design of reinforced concrete (RC) frame structures subject to combinations of gravity and lateral static loads based on ACI 318-08 design code. In the present work, artificial bee colony algorithm (ABCA) is focused and an improved ABCA (IABCA) is proposed to achieve the optimization task. The total cost of the RC frames is minimized during the optimization process subject to constraints on demand capacity ratios (DCRs) of structural members. Three benchmark design examples are tested using ABCA and IABCA and the results are compared with those of presented in the literature. The numerical results indicate that the proposed IABCA is an efficient computational tool for discrete optimization of RC frames. Received: 6 January 2015; Accepted: 11 March 2015 KEY WORDS: reinforced concrete frame; static loads; optimization; artificial bee colony algorithm. 1. INTRODUCTION Optimization of reinforced concrete (RC) frames is a complex problem, due to the large number of variables that influence the design process, the different nature of the variables and the various reinforcement details available for the design problem at hand. For RC frames three different cost components of concrete, steel and formwork should be considered and in this case a combination of design variables must be such determined that the total cost is minimal. As designing and constructing of cost effective structures is of high importance, optimization of RC frames has been attracted much attention in recent decades. * Corresponding author: Department of Civil Engineering, Urmia University, Urmia, Iran † E-mail address: s.gholizadeh@urmia.ac.ir (S. Gholizadeh)