ISSN: 1813-0410

Author : Hameed Naser Al-Mamoori, Ali


Ali Hameed Naser Al-Mamoori; Fatimah Hameed Naser Al-Mamoori; Maryam Hameed Naser Al-Mamoori

journal of kerbala university, 2018, Volume 14, Issue 1, Pages 232-249

In the present research, experimental study has been devoted to investigate the behavior of sixteen circular reinforced concrete short columns which have different lateral reinforcement and amount of steel fiber and they were tested under concentric compression till failure in order to discover the best confining column system and optimum steel fiber ratio.
These columns are categorized into four groups; each group has four specimens, the first specimen without steel fiber and other specimens containing steel fiber with different ratio (0.5%, 0.75% and 1.0%).
All specimens have the same geometry and longitudinal reinforcement but differ, in the type of lateral reinforcement divided in three groups (no lateral reinforcement, tied lateral reinforcement and spiral lateral reinforcement; the spiral and tied reinforcement have approximately the same amount of reinforcement.) Also, these specimens compared with no longitudinal and no laterals reinforcement (plain concrete columns) as control specimens in the first group.
In this study, a crushed recycled concrete was used as a coarse aggregate combinations with natural aggregate (25% replacement of natural aggregate by a crushed recycled concrete) to produce concrete without any chemical and mineral additions.
The experimental results indicated that the use of steel fiber in columns caused increase rate in ultimate load are higher than normal concrete column but at certain limit less or equal 0.75%.
The combined effect of steel fibers and tied stirrups resulted in increasing the ultimate load in columns by about (7.39% - 23.34%) with respect to the same columns without lateral reinforced. While it's shown that the columns with steel fibers and spiral stirrups resulted in increasing the ultimate load by about (15.06% - 25.56%) with respect to the same columns without lateral reinforced. Also, it was observed that the behavior of spiral lateral reinforced concrete columns with or without steel fibers gives the best result when compared with other cases.