للكاتب
Alaa M. Rashad1
Housing & Building National RC, Egypt
Abstract:
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
characteristic strength, fcu, of 250 kg/cm2. Siliceous gravel aggregate has been used in
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.