Study on the compression performance of steel reactive powder concrete columns

2020 ◽  
Vol 23 (10) ◽  
pp. 2018-2029
Author(s):  
Hongbing Li ◽  
Fangbo Wu ◽  
Liangtao Bu ◽  
Yong Liu ◽  
Jiang Yao

In this study, the mechanical properties and failure characteristics of steel reactive powder concrete columns with different strength grades were investigated through compression testing. Six steel reactive powder concrete columns were tested; three columns underwent axial compression testing and three columns underwent eccentric compression testing. The results of the axial compression testing showed that steel and reactive powder concrete could work cooperatively at the initial stage, and the final column failure mode was primarily splitting failure at the end of the column, with the formation of a main crack in the longitudinal direction extending to the middle of the column. The results of the eccentric compression testing showed that the eccentrically loaded steel reactive powder concrete columns had comparatively strong deformability. The columns presented ductile failure mode under the eccentric load with 0.2 eccentricity. The final failure of the column involved a sudden increase in the horizontal crack width on the tension side, the steel flange on the tension side reached the yield state, the reactive powder concrete in the middle of the compressive side was crushed, and the reactive powder concrete surface layer burst open and partially spalled off. According to the test results and with reference to the relevant standards, equations for calculating the approximate ultimate bearing capacities of axially and eccentrically compressed reactive powder concrete columns were proposed.

2018 ◽  
Vol 24 (7) ◽  
pp. 75
Author(s):  
Mohammed Mosleh Salman ◽  
Husain Khalaf Jarallah ◽  
Raed Satar Al-Behadili

In this research, the structural behavior of reinforced concrete columns made of normal and hybrid reactive powder concrete (hybrid by steel and polypropylene fibers) subjected to chloride salts with concentration was 8341.6 mg/l. The study consists of two parts, the first one is experimental study and the second one is theoretical analysis.  Three main variables were adopted in the experimental program; concrete type, curing type and loading arrangement. Twenty (120x120x1200) mm columns were cast and tested depending on these variables. The samples were reinforced using two different bars; Ø8 for ties and Ø12 with minimum longitudinal reinforcement (0.01Ag). The specimens were divided into two main groups based on curing type: The first group consists of casting and testing of ten columns that cured in tap water for 28 days with two types of concrete (normal and hybrid), five columns for each type. While the second group consists of ten columns that direct cured and fully immersed in chloride water (8341.6 mg/l) 6 months with two types of concrete (normal and hybrid), five columns for each type. The specimens were tested under three types of loading, the first one is axial load, the second one is eccentric load with three different eccentricities (50,100 and 150) mm and where (e/h) are (0.42, 0.83 and 1.25) respectively from the center of column while the third type of loading is tested the specimens as beam. The experimental results showed an increase in ultimate load capacity and higher chlorides resisting for hybrid reactive powder concrete in comparison with normal concrete in both types of curing (tap and chloride water) through studying strain profile. Interaction diagram charts were obtained from different types of loading for each specimen. These charts showed high values for hybrid reactive powder concrete in comparison with normal concrete.  


2020 ◽  
Vol 6 (2) ◽  
pp. 363-374 ◽  
Author(s):  
Hasanain A. Shubbar ◽  
Nameer A. Alwash

This paper offers an experimental investigation of the fiber reinforced reactive powder concrete columns' behavior after exposure to fire and improvements made to improve column resistance against fire. This study is mainly aimed to study the experimental behavior of hybrid reinforced columns produced by reactive concrete powder (RPC) and exposure to the flame of fire at one side and subjected to eccentric load. The experimental methodology consists of sixteen RC columns that organized into four groups based on the variables used in this research: (SF) steel fibers, (PP) polypropylene fibers, (HB) hybrid fibers, (PPC-SF) hybrid cross-section (steel fiber reactive powder concrete core with polypropylene fiber reactive powder concrete cover). All columns were tested under 60 mm eccentric load and the burn columns were exposed to fire for different duration (1, 1.5 and 2) hours. The results indicated that (SF-RPC, PP-RPC, HB-RPC, PPC-SFRPC) columns exposed to a fire flame for the period 2 hours, lost from their load capacity by about (54.39, 40.03, 34.69 and 30.68) % respectively. The main conclusion of this paper is that the best fire resistance of the column obtained when using a hybrid cross-section (steel fiber reactive powder concrete core with polypropylene fiber reactive powder concrete cover).


2021 ◽  
Vol 30 (2) ◽  
pp. 315-326
Author(s):  
Mohammed Kadhum ◽  
Mustafa Abdulraheem ◽  
Yousif Funfakh ◽  
Michaela Gkantou ◽  
Zainab Mahdi ◽  
...  

The increased use of reactive powder concrete (RPC) in concrete structures has attracted attention towards the structural behavior of RPC in fires. This work examines experimentally the performance of RPC and NSC columns subjected to 25% of the ultimate load and exposed to direct fire flame for a period of 30 and 60 min at various temperature levels. The paper aims to evaluate the maximum temperature level and fire duration that can be withstood by this type of concrete columns. The results show that the failure mode of RPC columns without reinforcement is a sudden shear failure, whereas the failure mode of reinforced RPC columns is a crushing failure with rupture of certain ties. The RPC columns at high temperatures spall intensively; additionally, the ultimate strength clearly decreases compared to the NSC columns at the same conditions.


2012 ◽  
Vol 204-208 ◽  
pp. 4658-4663 ◽  
Author(s):  
Ran He ◽  
Xing Ping Shu ◽  
Bo Wang Chen

In order to study the characteristics about deformation and stress of four-tube concrete-filled steel tubular(CFST) laced columns of no yield point, a test with the parameter of eccentricity on two our-tube concrete-filled steel tubular(CFST) laced columns of no yield point has been finished by means of 500t press. The results of the test shows that the larger the eccentricity, the more obvious the global deformation of laced columns tends to become, and the four-tube CFST laced columns of no yield point under eccentric compression were subjected to overall bending failure and ductile failure with obvious premonition; In the meanwhile, confinement effect of main tubes away from the loading point of laced columns under eccentric compression was inapparent , while confinement effect of the two main tubes close to the loading point begain to play and increase before it was to fail, which made the characteristics about deformation and stress of the the two main tubes close to the loading point similar to the single CFST column under axial compression.


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