scholarly journals AN INVESTIGATION ON THE SHRINKAGE CHARACTERISTICS OF HYBRID FIBER REINFORCED CONCRETE PRODUCED BY USING FIBERS OF DIFFERENT ASPECT RATIO

2020 ◽  
Author(s):  
Rudraswamy M P ◽  
B.R Patagundi ◽  
K.B Prakash

In the present paper, effects of shrinkage in fiber reinforced concrete are studied.Here, in the current research work, an attempt is made to study the effects onshrinkage of concrete when five different fiber materials are used for reinforcing plainconcrete. Three configurations of each reinforcing fiber material is studied. Fiberaspect ratios of 40 and 100 and a combination of the fibers of the two aspect ratios inequal proportion (hybrid) make up the three configurations for one individual fibermaterial reinforcement. Shrinkage values are indicated in terms of total length ofcrack and the total area of the crack. On-field measurement of crack dimensions atperiodic time intervals ranging from 0 minutes to 28 days after casting of concrete hasbeen undertaken to determine the accurate values of shrinkage cracks in the fifteenscenarios i.e. five reinforcing fiber materials with three configurations each usingaspect ratio of fibers 40, 100 and the hybrid (40 +100) case. It is seen that,irrespective of the material of fiber used for reinforcing concrete, hybridized concreteconsistently shows better results relative to single aspect ratio fiber reinforcement.This research also aims to provide a bench mark for future research works onshrinkage characteristics of hybridized fiber reinforced concrete

2019 ◽  
Vol 8 (3) ◽  
pp. 1025-1028

The present work is enhancement of near surface characteristics for hybrid fiber reinforced concrete (aspect ratio 40+100). Here in this research work an attempt has made to study water absorption values for different types of fiber reinforced concrete, which are having different aspect ratios like 40, 100 and 40+100. Concrete mix along with fibers are casted and cured for 28days. Both water absorption test and sorptivity tests carried on hardened concrete. The main objective is to check variation in absorption values due to addition of different types of fibers. Here totally five different types of fibers are considered like steel fiber, Galvanized iron fibres, High density polyethylene fibres, waste plastic fiber and polypropylene fibers Experimental investigation shows that except polyprolene hybrid mix concrete other hybrid mixes has showed good results. But as compared to mono fiber reinforced concrete hybrid fiber reinforced concrete has showed better results. This research was aimed to provide benchmark for future research works on near surface characteristics of hybrid fiber reinforced concrete.


2021 ◽  
Vol 2 (3) ◽  
pp. 501-515
Author(s):  
Rajib Kumar Biswas ◽  
Farabi Bin Ahmed ◽  
Md. Ehsanul Haque ◽  
Afra Anam Provasha ◽  
Zahid Hasan ◽  
...  

Steel fibers and their aspect ratios are important parameters that have significant influence on the mechanical properties of ultrahigh-performance fiber-reinforced concrete (UHPFRC). Steel fiber dosage also significantly contributes to the initial manufacturing cost of UHPFRC. This study presents a comprehensive literature review of the effects of steel fiber percentages and aspect ratios on the setting time, workability, and mechanical properties of UHPFRC. It was evident that (1) an increase in steel fiber dosage and aspect ratio negatively impacted workability, owing to the interlocking between fibers; (2) compressive strength was positively influenced by the steel fiber dosage and aspect ratio; and (3) a faster loading rate significantly improved the mechanical properties. There were also some shortcomings in the measurement method for setting time. Lastly, this research highlights current issues for future research. The findings of the study are useful for practicing engineers to understand the distinctive characteristics of UHPFRC.


2019 ◽  
Vol 5 (1) ◽  
pp. 29 ◽  
Author(s):  
Nurullah Soylu ◽  
Ahmet Ferhat Bingöl

SIFCON (Slurry Infiltrated Fiber Reinforced Concrete) is a composite which occur hardening of the matrix phase, consists of cement, water, mineral additives, fine sand, water reducing plasticizer, and reinforced with high volume fiber (5–20%). The main difference from the high strength concrete (HSC) is the ductile behaviour at failure. However, the brittleness increases with the strength increase in HSC, SIFCON has a ductile behaviour because of the high volume fiber content, low permeability, high durability. Despite fiber content is 2-3% in fiber reinforced concrete, fiber content may be ten times more in SIFCON and ductility is gained. This concrete is suggested to be used in military buildings against explosion, industrial grounds, airports, and bridge feet. In this study, in order to investigate the compressive and flexural strengths of SIFCON, the aspect ratio and fiber volume of steel fibers were chosen as variable and the effects of these parameters on compressive and flexural strengths were investigated. In the study, steel fibers with aspect ratio of 40, 55, 65, and 80 were used in 0, 4, 8 and 12% ratios. The water/binder ratio was kept constant at 0.35. Silica fume is used 10% and water-reducing plasticizer is used 1.5% of cement by weight. 7 and 28 days cured samples were subjected to compressive and flexural tests and the results were compared. As a result of the tests carried out, increases in both the compressive and flexural strengths of SIFCON specimens were determined with increasing fiber volume up to 8%. Strength reductions were observed at higher ratios. In cases where the fiber volume is too high, it has been seen that the strengths were decreased. The reason of strength reduction can be explained by the difficulty of passing ability of mortar between the fibers. The highest strengths were obtained from fibers with the aspect ratio of 80. Increase in the aspect ratio as well as increases in compressive and flexural strengths have been found.


Concrete is hard but liable to break easily. Hybrid fiber reinforced concrete offers several economical and technical benefits. The use of fibers extends its possibilities. The hybridization of different types of fibers may play important roles in arresting cracks and thus achieve high performance of concrete. The main reason for adding glass ,steel and polypropylene to improve the ductility of concrete.The present research work is aimed at studying, the deep beam using three different types of fibers such as glass 0.3%, steel 0.75% & 1% and polypropylene fibers 0.3% were added to volume of concrete. The mix design has been arrived based on IS code method for M20 grade of concrete. An investigation is carried out to evaluate the fresh Properties and mechanical Properties of Hybrid Fiber Reinforced Concrete (HFRC). The result shows that hybrid fiber reinforced deep beams achieved better performance than the ordinary RC deep beam under application of load.


2009 ◽  
Vol 610-613 ◽  
pp. 69-75
Author(s):  
Yuan Hua ◽  
Tai Quan Zhou

Different kinds of fiber are used to reinforce the concrete to improve the concrete mechanical properties. The high modulus and high flexibility fibers are often used to reinforce in the cement base, which leads to the higher performance compound cement based materials. In the paper, the carbon fiber and glass fiber material are used as flexibility reinforced materials. The polypropylene fiber and the polyethylene fiber are used as strength reinforced materials. The combinations of the flexibility reinforced fiber and strength reinforced fiber are chosen as C-P HF (Carbon and Polypropylene Hybrid Fiber) and G-Pe HF (Glass and Polyethylene Hybrid Fiber). The concrete mixture ratio and the fiber-reinforced amount are determined to the author’s previous study. The relationship between compressive strength, flexural strength and length/diameter aspect ratio of fiber for the carbon and polypropylene hybrid fiber reinforced concrete (C-P HFRC), and for the glass and polyethylene hybrid fiber reinforced concrete (G--Pe HFRC) was tested and discussed. The testing results show that length/diameter aspect ratio of fiber obviously affects the flexural strength of C-P HFRC and G-Pe HFRC, though the compressive strength is slightly affected by the length-diameter aspect ratio.


2018 ◽  
Vol 2018 ◽  
pp. 1-23
Author(s):  
Lihua Xu ◽  
Cuimei Wei ◽  
Biao Li

This paper presents an experimental investigation on the stress-strain behavior and damage evolution of steel-polypropylene hybrid fiber reinforced concrete (HFRC) with different fiber types, volume fractions, and aspect ratios. The damage evolution laws of HFRC were obtained using uniaxial cyclic compression and tension tests. The results show that the addition of hybrid fiber has a significant synergetic effect on the mechanical behavior of concrete. The peak strength, peak strain, toughness, and postpeak ductility of HFRC under both tension and compression are improved, and the damage accumulation and stiffness degradation are alleviated by increasing volume fractions of SF and PF, as well as aspect ratios of SF. Moreover, the steel fiber volume fraction shows a more pronounced effect than that of other considered factors on the enhancement of cyclic mechanical parameters of HFRC. Based on the unloading stiffness degradation process, analytical equations were, respectively, proposed to generalize the damage progression of HFRC under compression and tension, with the effects of hybrid fiber taken into consideration. Finally, the proposed uniaxial damage evolution equations combined with the calibrated concrete damaged plasticity (CDP) model in ABAQUS were used to predict the responses of HFRC materials and structural members subjected to shear and seismic loads. The comparisons between the numerical predictions and experimental results show a good agreement.


2010 ◽  
Vol 168-170 ◽  
pp. 2143-2149
Author(s):  
Wei Dong Zhuo ◽  
Shang Guan Ping ◽  
Yin Gu

The flexural fatigue performance of polyacrylonitrile (PAN) fiber reinforced concrete (PANFRC)was investigated by third-point loading tests. Based on the previous research work, optimum mixture proportions of PANFRC for highway overlays and bridge decks that satisfied both the minimum compressive and bending strengths, and showed excellent mechanical properties, were selected for fatigue testing. The experimental program included a total of 69 flexural specimens, 15 of which were plain concrete specimens, and the remaining 54 specimens were PANFRC specimens. Three mixes containing 0.0%, 0.1 %, and 0.15% of PAN fiber volume fractions were selected. For each mix, 4 different target load ranges were applied: 10–75%, 10–80%, 10–85%, and 10–90% of the ultimate flexural capacity, as obtained from the corresponding control static test. The bending fatigue life of PANFRC specimens under various stress ratios are proved to follow two-parameter Weibull distribution. Both a semi-logarithm and a double-logarithm P-S-N equations with various failure probabilities are derived from the experimental measurements. The denifition of the fatigue damage variable and damage evolution equation for PANFRC are furtherly proposed based on theory of continuum damage mechanics.


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