Effects of adding brass byproduct on the basic properties of concrete

The use of industrial byproducts in the concrete industry has become a common and attractive practice in recent years. It offers alternative materials for making concrete and reduces the environmental risk associated with these industrial byproducts. One industrial byproduct is that associated with the production of brass. Brass byproduct (BBP) typically comes in the form of thin, flexible strips which can be cut down into small fibers and used in concrete. The brass waste represents an environmental issue, and its management by recycling in the concrete industry could be a considerable achievement. This paper discusses the feasibility of adding BBP to normal concrete. The effects of the incorporation of BBP on the basic properties of fresh and hardened concrete were experimentally investigated. Three control mixtures (strong, regular, and lean) were designed with w/c of 0.45, 0.5, and 0.6, respectively. The BBP was added to these mixes at variable dosages ranging from 5% to 30% by weight of the cement. A total of 21 mixes (3 control and 18 with BBP) were designed and tested in this study. The effects of adding BBP on the concrete workability, compressive strength, flexural strength, and Ultrasonic Pulse Velocity (USPV, as a measure of strength) were investigated. Several concrete cubes and flexural beams specimens were cast from each concrete mix and were moist-cured until the day of testing. The workability of fresh concrete was also measured for all mixes using a standard slump test. Compressive strength and flexural strength were measured at two ages (28 days and 90 days). The USPV was also recorded at these testing ages on the cube samples. The results obtained showed that mechanical properties (compressive and flexural strength) and USPV increased with increasing brass byproducts less than 10-15%, but, significantly decreased when the content exceeded 15%. The results also showed that workability properties decreased as brass byproducts content increased. These results suggest an optimum rate of addition of the BBP in the range of 10-15% by weight of cement. (C) 2012 Elsevier Ltd. All rights reserved.