A RESEARCH ABOUT THE METHODS FOR RESTORING OF RC SHORT COLUMN UNDER THE PRELOADING CONDITIONS

Housing & Building National RC, Egypt

The objective of the present research work is to restore the ultimate carrying capacity

of spalled columns without increasing their original sizes when the applied loads are

considered to represent about 100%, 75% and 0% of the ultimate load. Eighteen RC

column specimens with concrete cover 2.5 cm and a specimen dimensions 15x15x70

cm were cast and reinforced with 4 ø 8 mm longitudinal reinforcement and 9 ø 4 mm

stirrups equally distributed along the height. The concrete mix is designed to give

preparing the concrete mix. Column specimens are divided into three groups. Each

group is used to investigate certain type of restoring the concrete cover. Three

different types of restoring have been used in this study namely fiber-reinforced

concrete, plain concrete and cement mortar alternatively. The experimental results

showed that, the capacities of restored column specimens were influenced by

compressive strength of repaired materials and the condition of preloading.