scholarly journals Verification of the Structural Performance of Textile Reinforced Reactive Powder Concrete Sandwich Facade Elements

2019 ◽  
Vol 9 (12) ◽  
pp. 2456 ◽  
Author(s):  
Mathias Flansbjer ◽  
Natalie Williams Portal ◽  
Daniel Vennetti
Keyword(s):  
Structural Model ◽  
Structural Performance ◽  
Wind Loading ◽  
Experimental Program ◽  
Reactive Powder Concrete ◽  
Uniaxial Tensile ◽  
Material Development ◽  
Pull Out ◽  
Glass Fiber Reinforced ◽  
Reactive Powder

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.

Abrasion of Reactive Powder Concrete under Direct Water Impact

2020 ◽  
Vol 897 ◽  
pp. 41-48 ◽  
Author(s):  
Munther L. Abdul Hussein ◽  
Sallal R. Abid ◽  
Sajjad H. Ali
Keyword(s):  
Steel Fiber ◽  
Fiber Type ◽  
Polypropylene Fiber ◽  
Experimental Program ◽  
Reactive Powder Concrete ◽  
Fiber Distribution ◽  
Hybrid Fiber ◽  
Normal Concrete ◽  
Weight Losses ◽  
Reactive Powder

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.

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 Flexural Behavior of Reactive Powder Concrete with Hybrid Section T- Beams

2021 ◽  
Author(s):  
Rafid Saeed Atea
Keyword(s):  
Silica Fume ◽  
Flexural Behavior ◽  
Experimental Program ◽  
Reactive Powder Concrete ◽  
Normal Concrete ◽  
Hybrid Beams ◽  
Hybrid Section ◽  
Current Duration ◽  
Reactive Powder ◽  
T Beam

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%.

scholarly journals Behavior of Hybrid Reactive Powder Concrete Columns Exposed to Chloride Attack

2018 ◽  
Vol 21 (3) ◽  
pp. 327-343
Author(s):  
Mohammed \m. Salman ◽  
Husain K. Jarallah ◽  
Raed Satar Al-Behadili
Keyword(s):  
Tap Water ◽  
Load Capacity ◽  
Concrete Columns ◽  
Neutral Axis ◽  
Experimental Program ◽  
Reactive Powder Concrete ◽  
Vertical Load ◽  
Ultimate Load Capacity ◽  
Chloride Water ◽  
Reactive Powder

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.  

scholarly journals Behavior of Reinforced Reactive Powder Concrete Two-Way Slabs under Static and Repeated Load

2018 ◽  
Vol 4 (6) ◽  
pp. 1178 ◽  
Author(s):  
Hala Aqeel Hamid ◽  
Shatha D. Mohammed
Keyword(s):  
Ultimate Load ◽  
Ultimate Strain ◽  
Steel Fibers ◽  
Experimental Program ◽  
Dissipated Energy ◽  
Reactive Powder Concrete ◽  
Absorbed Energy ◽  
Static Test ◽  
Repeated Load ◽  
Reactive Powder

This paper studies the behavior of reinforced Reactive Powder Concrete (RPC) two-way slabs under static and repeated load. The experimental program included testing six simply supported RPC two-way slabs of 1000 mm length, 1000 mm width, and 70 mm thickness. All the tested specimens were identical in their material properties, and reinforcement details except their steel fibers content. They were cast in three pairs, each one had a different steel fibers ratio (0.5 %, 1 %, and 1.5 %) respectively. In each pair, one specimen was tested under static load and the other under five cycles of repeated load (loading-unloading). Static test results revealed that increasing steel fibres volume fraction from 0.5 % to 1 % and from 1% to 1.5%, led to an increase in the: first crack load by (32.2 % and 52.3 %), ultimate load by (36.1 % and 17.0 %), ultimate deflection by (33.6 % and 3.4 %), absorbed energy by (128 % and 20.2 %), and the ultimate strain by (1.1 % and 6.73 %). It also increased the stiffness and the ductility of the specimens especially at the final stages of loading. Additionally, it delayed the propagation of the cracks, controlled their growth, kept the integrity of the specimens at post cracking stage, and avoided their ruin at the failure stage through its “bridging” effect. For the repeated load test, applying five cycles of repeated load to the steel fiber reinforced RPC two-way slab specimens led to a decreasing in the ultimate load capacity, ultimate deflection, ultimate strain, and absorbed energy in a comparison with the corresponding static test specimens, and that because of the loading-unloading process which causes a fluctuation of stresses and more damages in concrete. Increasing the steel fibers volume fractions decreased the dissipated energy of the specimens that subjected to a repeated load, where the difference percent of dissipated energy between the first and second cycles of (R0.5 %, R1 %, and R1.5 %) specimens were (68.0 %, 46.2%, and 32.4%) respectively.

scholarly journals Repairing of Reactive Powder Concrete T-Beams Containing Web Opening by CFRP Strips

2019 ◽  
Vol 26 (1) ◽  
pp. 9-19
Author(s):  
Mazin B. Abdulrahman ◽  
Husham M. Rashid
Keyword(s):  
Carrying Capacity ◽  
Ultimate Load ◽  
Experimental Program ◽  
Reactive Powder Concrete ◽  
Shape Effect ◽  
Load Carrying Capacity ◽  
Test Results ◽  
Load Carrying ◽  
Ultimate Load Carrying Capacity ◽  
Reactive Powder

In modern buildings, transverse openings are often used beams for the purpose of supplying and service pipes. Due to the presence of the openings in the concrete beams lead to the formation of cracks around the openings due to the stresses concentration in a small area above and below of the opening. The repairing, maintenance, and upgrading of structural members, are maybe one of the most pivotal problems in civil engineering applications. In this research, an experimental work is conducted to study the behavior of the reinforced RPC T-beams that containing openings and repair this beams using CFRP strips. The Experimental program of the present study includes two parts, the first part includes testing of seven reinforced reactive powder concrete RPC T-beams, which casted and tested, one beam is without opening as a reference beam and the rest, were provided with an opening. and these beams are divided into two groups. The first group was used to study the effect of the openings shape (circular and square) and the second group was used to study the effect of the openings locations, which consists three locations (Lc/2, Lc/3 and Lc/4).These are measured from the support center to the openings center. While the second part including a repaired all beams in the first part the using carbon fiber polymer. The test results indicated that the presence of openings in the beams web caused a reduction in the reinforced RPC T-beams ultimate load carrying capacity with about (10-55)%, Also lead to increasing in deflection compared to control beam before repairing at same loading. Studying the shape effect showed that the beams with square openings have average ultimate load carrying capacity lower by 36% compared with the control beams.While beams with containing circular openings have average ultimate load carrying capacity lower 29%. From the test results, it could be concluded that the presence of the openings in the shear region led to a decrease in ultimate load carrying capacity a about 38% to 49% for opening of opening at (Lc/3 and Lc/4) respectively. While the presence of openings in the flexural region led to a decrease in the ultimate load carrying capacity rate of 11%. Related to the repairing study part it was found that the average ultimate load carrying capacity for repairing beams was 103% compared with the not repaired beams.

Fracture Energy of Reactive Powder Concrete Based on Uniaxial Tensile Test

2011 ◽  
Vol 306-307 ◽  
pp. 519-522
Author(s):  
Hai Yan Yuan ◽  
Ming Zhe An ◽  
Fang Fang Jia ◽  
Zhi Gang Yan
Keyword(s):  
Tensile Test ◽  
Fracture Energy ◽  
Testing Machine ◽  
Strain Curve ◽  
Reactive Powder Concrete ◽  
Uniaxial Tensile ◽  
Uniaxial Tensile Test ◽  
Stress Strain Curve ◽  
Concentration Problem ◽  
Reactive Powder

Based on uniaxial tensile test, the complete uniaxal tensile stress-strain curve of Reactive Powder Concrete (the steel fiber content by volume is Vf =1%, 2%) was obtained, and the fracture energy of RPC specimens with cross-section of 100mm by 100mm was calculated. The test was finished through Universal Testing Machine without any stiffness-strengthen devices. In order to solve the stress concentration problem, a self-designed uniaxial tensile test equipment was developed, and a dumbbell-shaped specimen was used in the test. The results indicate that the fracture energy of RPC increased as well as the increasing of Vf.

scholarly journals Effect of Fly Ash on Some Properties of Reactive Powder Concrete

2021 ◽  
Vol 27 (11) ◽  
pp. 32-46
Author(s):  
Zahraa F Muhsin ◽  
Nada Mahdi Fawzi
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Fly Ash ◽  
Industrial Wastes ◽  
Experimental Program ◽  
Reactive Powder Concrete ◽  
Binder Ratio ◽  
Reactive Powder ◽  
Water To Binder Ratio

To achieve sustainability in the field of civil engineering, there has become a great interest in developing reactive powder concrete RPC through the use of environmentally friendly materials to reduce the release of CO2 gas produced from cement factories as well as contribute to the recycling of industrial wastes that have a great impact on environmental pollution. In this study, reactive powder concrete was prepared using total binder content of 800 kg/m3, water to binder ratio (0.275), and micro steel fibers  1% by volume of concrete. The experimental program included replacing fly ash with (8, 12, 16) % by cement weight to find the optimal ratio, which achieved the best mechanical properties of (RPC) at 7, 28, and 90 days with standard curing. Some mechanical properties of reactive powder concrete (flow, compressive strength, tensile strength, and density) were verified. The results at 28 days showed that the compressive strength (96.5) Mpa, tensile strength (9.38) Mpa, and density (2395 kg/m3). The results showed that the percentage of replacement of 8% of fly ash with cement is the optimal percentage, which achieved the highest resistance compared to the others. The results also indicated that it is possible to develop RPC using fly ash with a high withstand stress, tensile strength, and density.

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