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

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.  

2018 ◽  
Vol 21 (3) ◽  
pp. 327-343
Author(s):  
Mohammed \m. Salman ◽  
Husain K. Jarallah ◽  
Raed Satar Al-Behadili

In this paper, the cross section behavior of reinforced concrete columns made of normal and hybrid reactive powder concrete (hybrid by steel and polypropylene fibers) under concentric and eccentric vertical load was study. The casted columns were cured in two different type tap water for 28 days and chloride water for six months. Chloride salts with concentration was 8341.6 mg/l. Three variables were adopted in the experimental program; concrete type, curing type and the eccentricity of vertical load. Twenty (120x120x1200) mm columns were casted and tested depending on these variables. The different eccentricities were (0, 50,100 and 150) mm and where (e/h) were (0, 0.42, 0.83 and 1.25) respectively from the center of column, the other types of loading are tested the specimens as beam. The experimental results showed increasing 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 load deflection, test results for Normal Strength Concrete (NSC) and Hybrid Fiber Reactive Powder Concrete (HFRPC) columns that deflection for columns cured in chloride water more than tap water when compared at the same load that also by increase eccentricity leads to an increase in deflection for both cured and The neutral axis depth for HFRPC columns is more than NSC at the same load also when eccentricity increases, the compression zone decreases and neutral axis also decrease by increase eccentricity. These results occur when columns are cured in tap and chloride water.  


2019 ◽  
Vol 13 (1) ◽  
pp. 260-270
Author(s):  
Yaarub G. Abtan ◽  
Hassan Falah Hassan

Background: Over the last three decades, the interest in using advanced high-performance materials in the construction industry has been increasing worldwide. Recently, a very high strength cement-based composite with high ductility called Reactive Powder Concrete (RPC) has been developed. The RPC concept is based on the principle that a material with a minimum of defects such as micro-cracks and voids will be able to achieve greater load-carrying capacity and durability. Methods: In the present paper, an experimental program of sixteen reinforced concrete one-way slabs was conducted to investigate their behavior under flexural loading. Four of these slabs were with Normal Concrete (NC) and the others of Modified Reactive Powder Concrete (MRPC). All slabs were identical in the dimension of its length and width (1000×500) mm, respectively, and its thickness was varied as one of the variables used in the present work. Other parameters for a one-way slab are concrete type, steel fibers content and flexural steel reinforcement ratio (0.33 and 0.66)%. Results: The results showed that the MRPC slabs with steel fibers failed in a ductile manner and had ultimate load capacity more than that of non-fibrous MRPC with an improvement percentage that reaches up to (66) %. This percentage became (212) % in comparison with normal concrete slabs. Conclusions: Moreover, the results showed that slabs, for both concrete types, reinforced with lower steel ratio failed by tension mode, otherwise, the slabs of higher reinforcement steel ratio failed by combined tension-shear mode. However, an improvement was observed in the ultimate load capacity up to (53 and 98) % when the ratio of steel reinforcement and slab thickness increased, respectively.


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.


2020 ◽  
Vol 897 ◽  
pp. 41-48 ◽  
Author(s):  
Munther L. Abdul Hussein ◽  
Sallal R. Abid ◽  
Sajjad H. Ali

An experimental program was directed in this study to evaluate the abrasion resistance of reactive powder concrete (RPC) under direct normal impact of water jet. Abrasion and compressive strength specimens were cast from six RPC mixtures using different single and hybrid distributions of 6 mm-length and 15 mm-length micros-steel fibers and 18 mm-length polypropylene fiber. Fixed mix proportions were used for the six RPC mixtures and with fixed total volumetric fiber content of 2.5%. In addition to the RPC mixtures, a normal concrete mixture was prepared for comparison purposes. All specimens were cured in the same conditions and tested at an age of 28 days. The test results showed that abrasion weight losses increase with time at rates that are independent of fiber type and fiber distribution. The results also showed that all RPC mixtures exhibited significantly lower abrasion losses than normal concrete. The lowest percentage abrasion weight losses were recorded for the mixture with pure 15 mm micro-steel, where after 12 testing hours, it was 0.41% of the total weight before testing. On the other hand, the mixture with pure 6 mm micro-steel fiber exhibited the highest percentage abrasion weight loss (0.98%) among the six RPC mixtures. Another conclusion is that the inclusion of polypropylene fiber to compose hybrid fiber distribution with micro-steel fiber led mostly to lower abrasion losses.


2021 ◽  
Author(s):  
Rafid Saeed Atea

Abstract Reactive powder concrete (RPC) is unique of the present and greatest significant improvements in constructions field, it has usual excessive kindness happening current duration in the world owing toward its higher concrete properties, great ductility, durability, shrinkage, great opposition to corrosion and abrasion. In this experimental investigation is carried out on the way to revision the RPC flexural activity with Hybrid Segment T- Beams and the mechanical characteristics of this building material. In order to analyze the belongings of steel fiber volumetric ratio, silica fume ratio, tensile steel ratio, hybrid section on RPC T-beam flexural efficiency, the experimental program included testing five beams. The study was focused on determining the load-deflection behavior, letdown mode, strain supply across the depth of the beams and crack pattern at failure. The results of the volumetric ratio of steel fibers and the silica fume ratio were also considered in studying the mechanical properties of RPC mixes. Moreover, a study of hybrid beams showed that use of RPC web and normal concrete in flange efficiently improves the performance of T-beams compared to normal concrete T-beams with a percentage rise of 12 percent and hybrid beams have also shown that the use of RPC flange and normal concrete in web efficiently improves the display of T-beams associated to regular concrete T-beams with percentages increase of 28%.


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).


2019 ◽  
Vol 27 (3) ◽  
pp. 12-20
Author(s):  
Muhammad Abbassi ◽  
Hooshang Dabbagh

Abstract In this research, which is based on the finite element method, the behavior of reactive powder concrete (RPC) columns confined with fiber-reinforced polymer (FRP) under seismic excitation is investigated. The governing theory in the numerical simulation is based on the fiber finite element method. The adequacy of the fiber model in predicting the response of FRP-confined RPC columns is validated through comparisons with the available experimental results. To study the seismic behavior of FRP-confined RPC columns, the fiber model presented was subjected to different earthquakes. In this regard, four ground acceleration time histories with different peak accelerations were applied to investigate the response of FRP-confined RPC columns. The results show that reactive powder concrete columns confined with FRP exhibit an acceptable seismic performance. The investigation also confirms that RPC-confined columns show a high degree of ductility. Additionally, the load capacity (maximum lateral load) is increased, and the concrete’s compressive strength is increased.


2019 ◽  
Vol 9 (12) ◽  
pp. 2456 ◽  
Author(s):  
Mathias Flansbjer ◽  
Natalie Williams Portal ◽  
Daniel Vennetti

As a part of the SESBE (Smart Elements for Sustainable Building Envelopes) project, non-load bearing sandwich elements were developed with Textile Reinforced Reactive Powder Concrete (TRRPC) for outer and inner facings, Foam Concrete (FC) for the insulating core and Glass Fiber Reinforced Polymer (GFRP) continuous connectors. The structural performance of the developed elements was verified at various levels by means of a thorough experimental program coupled with numerical analysis. Experiments were conducted on individual materials (i.e., tensile and compressive tests), composites (i.e., uniaxial tensile, flexural and pull-out tests), as well as components (i.e., local anchorage failure, shear, flexural and wind loading tests). The experimentally yielded material properties were used as input for the developed models to verify the findings of various component tests and to allow for further material development. In this paper, the component tests related to local anchorage failure and wind loading are presented and coupled to a structural model of the sandwich element. The validated structural model provided a greater understanding of the physical mechanisms governing the element’s structural behavior and its structural performance under various dead and wind load cases. Lastly, the performance of the sandwich elements, in terms of composite action, was shown to be greatly correlated to the properties of the GFRP connectors, such as stiffness and strength.


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

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