STUDY OF CONCRETE-MASONRY COMPOSITE COLUMNS

Abstract

Concrete is a versatile construction material. The main draw back of concrete construction is the need of expensive formworks. In some cases for a particular structure formwork costs more than concrete and reinforcing steel. One alternative to eliminate the need of expensive formwork is to adopt construction in which brick units bonded in mortar are aligned along perimeter and inside cast-in-situ concrete is placed. Subsequently after the hardening concrete and masonry will act integrally to resist forces. In case of concrete masonry composite columns after building five to six courses for a height equal to 60 - 70 cm., concrete is placed between the bricks in the core. The water cement ratio is usually on higher side to allow the concrete to flow. Hand compaction is generally used since vibration may cause bricks to be pushed out of place. In the present dissertation, experimental study of six concrete-masonry composite columns are reported. Three columns with different ties arrangement were tested under axial loads and three columns under eccentric loads. All the columns were tested under increasing loads until failure occurs.