Despite its excellent physical and mechanical properties, polymer concrete has not been widely used owing to its much higher unit price than conventional portland cement concrete. To ensure the economic efficiency of polymer concrete, it is utmost important to reduce the use of polymer binder, which occupies most of the production cost of polymer concrete. Based on the experimental investigations, replacing filler (calcium carbonate) and fine aggregate (river sand) with fly ash and rapid-cooled steel slag (RCSS), which are spherical materials obtainable from industrial by-products, was found to be effective for improving the strength characteristics and durability as well as the cost efficiency of polymer concrete. The product developed in this study successfully reduced the demand for polymer binder by 21.3% compared to the conventional product, which in turn saved the total material costs by 18.5%. Although the use of RCSS showed performance degradation at an elevated temperature condition, considering typical temperature ranges that actual concrete infrastructures experience, it is expected that the polymer concrete using fly ash and RCSS will provide high-level performances as construction and repair materials. (c) 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013