scholarly journals Experimental investigation on the post-fire performance of reactive powder concrete columns

2021 ◽  
Vol 30 (2) ◽  
pp. 315-326
Author(s):  
Mohammed Kadhum ◽  
Mustafa Abdulraheem ◽  
Yousif Funfakh ◽  
Michaela Gkantou ◽  
Zainab Mahdi ◽  
...  
Keyword(s):  
Failure Mode ◽  
Shear Failure ◽  
Ultimate Load ◽  
Concrete Columns ◽  
Maximum Temperature ◽  
Reactive Powder Concrete ◽  
Fire Performance ◽  
Temperature Levels ◽  
Fire Flame ◽  
Reactive Powder

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.

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
Keyword(s):  
Failure Mode ◽  
Axial Compression ◽  
Ductile Failure ◽  
Concrete Columns ◽  
Compression Testing ◽  
Reactive Powder Concrete ◽  
Sudden Increase ◽  
Eccentric Load ◽  
Eccentric Compression ◽  
Reactive Powder

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.

scholarly journals Behavior of Reactive Powder Concrete Beams Exposed to Fire

2021 ◽  
Vol 14 (4) ◽  
pp. 1-10
Author(s):  
Mahmoud Ahmed Ali ◽  
Aboelwafa Elthakeb ◽  
Usama Mohamed ◽  
Mohamed Taha Noaman
Keyword(s):  
Ultimate Load ◽  
Concrete Beams ◽  
Reinforced Concrete Beams ◽  
Service Load ◽  
Maximum Crack ◽  
Temperature Levels ◽  
Fire Flame ◽  
Reactive Powder ◽  
And Behavior ◽  
The Relationship

In this paper, the effect of direct fire flame and steel fiber ratio on some mechanical properties and behavior of the relationship between load and deflection of rectangular reinforced concrete beams under the influence of fire exposure was studied. Concrete specimens were exposed to fire at temperatures ranging from (25- 400 ºC). Three temperature levels of (200, 300, 400 ºC) where chosen for exposure duration of 2.0 hours. After conducting the test, it was found that increasing the proportion of steel fibers in percentages 0.5% to 1% and 1.5% decreases the mid-span deflection at service load by 33%, 50% and 37.5 and increases the ultimate load by 36.36%, 41.6% and 53% respectively. After the beams are exposed to fire, it was noticed that the maximum crack width increases with increasing fire temperature.

Investigate on Pore Structure Characteristics of Reactive Powder Concrete after High Temperatures

2012 ◽  
Vol 174-177 ◽  
pp. 1010-1014 ◽  
Author(s):  
Hong Bin Liu ◽  
Yang Ju ◽  
Kai Pei Tian ◽  
Jin Hui Liu ◽  
Li Wang ◽  
...  
Keyword(s):  
Pore Structure ◽  
Pore Size ◽  
Pore Volume ◽  
Average Pore Size ◽  
Reactive Powder Concrete ◽  
Characteristic Parameters ◽  
Average Pore ◽  
Structure Characteristics ◽  
Temperature Levels ◽  
Reactive Powder

The pore structure characteristics of reactive powder concrete (RPC) were investigated by means of the mercury injection method at seven temperature levels, namely, 20°C, 100°C, 150°C, 200°C, 250°C, 300°C, 350°C, respectively. The characteristic parameters such as porosity, pore volume, average pore size and threshold aperture varied with temperatures were analyzed. The results indicate that the porosity, pore volume, threshold aperture and other characteristic parameters of RPC increased with the temperature increasing.

scholarly journals Behaviour of Reactive Powder Concrete Columns without Steel Ties

2008 ◽  
Vol 6 (2) ◽  
pp. 377-386 ◽  
Author(s):  
Adnan R. Malik ◽  
Stephen J. Foster
Keyword(s):  
Concrete Columns ◽  
Reactive Powder Concrete ◽  
Reactive Powder

Strengthening of Modified Reactive Powder Concrete Columns with CFRP

2016 ◽  
Vol 10 (1) ◽  
pp. 107-123
Author(s):  
Mutaz Kadhim Medhlom ◽  
◽  
Mohammed Hashim Mohammed ◽  
Keyword(s):  
Concrete Columns ◽  
Reactive Powder Concrete ◽  
Reactive Powder

Fire performance of highly flowable reactive powder concrete

2009 ◽  
Vol 23 (5) ◽  
pp. 2072-2079 ◽  
Author(s):  
Chin-Tsung Liu ◽  
Jong-Shin Huang
Keyword(s):  
Reactive Powder Concrete ◽  
Fire Performance ◽  
Reactive Powder

scholarly journals Experimental Investigation of Short Square Normal and Hybrid Fiber Reactive Powder Concrete Columns Subjected to Chloride Solution Attack

2018 ◽  
Vol 24 (7) ◽  
pp. 75
Author(s):  
Mohammed Mosleh Salman ◽  
Husain Khalaf Jarallah ◽  
Raed Satar Al-Behadili
Keyword(s):  
Tap Water ◽  
Load Capacity ◽  
Concrete Columns ◽  
Experimental Program ◽  
Reactive Powder Concrete ◽  
Normal Concrete ◽  
Ultimate Load Capacity ◽  
Eccentric Load ◽  
Chloride Water ◽  
Reactive Powder

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.  

scholarly journals Structural Behavior of Continuous Steel-Reactive Powder Concrete Composiate Beams Under Repeated Loads

2018 ◽  
Vol 7 (4.19) ◽  
pp. 843
Author(s):  
Rasha Yassien Dakhil ◽  
Mustafa B. Dawood
Keyword(s):  
Ultimate Load ◽  
Concrete Beams ◽  
Numerical Models ◽  
Experimental Tests ◽  
Reactive Powder Concrete ◽  
Mode Of Failure ◽  
Reactive Powder ◽  
And Behavior ◽  
Push Out ◽  
Repeated Loads

A study for the continuous composite steel-reactive powder concrete beams under repeated loads were executed experimentally and analytically. In the experimental part, six continuous composite sections were constructed as test beams. "The‘“decks slab concretes"was connected tos steel I-beams by headed steel studs welded to the top flanges“ofs“thes‘‘steel I-beams.“T,he dimensions“ of “the“ deck slab is (2200×250×80mm), while the type of I-beam is (IPE 140) with length of (2200mm). For the present work, the experimental work includes also examining the shear in the links by creating two models (push out) and tested to determine the properties and behavior of the studs. The behavior of the studs were conducted by"getting load-slip curves. In the part of the,oretical,‘‘.tested beams.was numericallysmodeled then analyzed using thesfinite element method.‘“Thes“numerical models were carried out in three dimensionss bys“the software package (ANSYS 16.1). Verifi,cationsof thesnumericalsresults“was donesbyscompari,ngs thems with the experimentals results. “Thesresultssof thesfiniteselementsanalysissshowed good agreements‘with the results ofsthe experimental tests. The maximumsandsminimum difference‘‘in ultimate loa,ds for beams‘‘ were (5.85% and 1.33%) respectively.  The results show that stiffenerssof beamssandsstrengthening with CFRP shall increase the ultimate load capacity‘and affects on‘‘mode of failure“ of theses beams.‘  

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