scholarly journals THEORETICAL EVALUATION OF THE TENSILE STRENGTH OF CONCRETE REINFORCED WITH STEEL FIBER WITH CURVED ENDS

Author(s):  
R. Kinash ◽  
V. Bilozir ◽  
І. Bidenko
2018 ◽  
Vol 162 ◽  
pp. 02001
Author(s):  
Wasan Khalil ◽  
Hisham Ahmed ◽  
Zainab Hussein

In this investigation, sustainable High Performance Lightweight Aggregate Concrete (HPLWAC) containing artificial aggregate as coarse lightweight aggregate (LWA) and reinforced with mono fiber, double and triple hybrid fibers in different types and aspect ratios were produced. High performance artificial lightweight aggregate concrete mix with compressive strength of 47 MPa, oven dry density of 1828 kg/m3 at 28 days was prepared. The Fibers used included, macro hooked steel fiber with aspect ratio of 60 (type S1), macro crimped plastic fiber (P) with aspect ratio of 63, micro steel fiber with aspect ratio of 65 (type S), and micro polypropylene fiber (PP) with aspect ratio of 667. Four HPLWAC mixes were prepared including, one plain concrete mix (without fiber), one mono fiber reinforced concrete mixes (reinforced with plastic fiber with 0.75% volume fraction), one double hybrid fiber reinforced concrete mixes (0.5% plastic fiber + 0.25% steel fiber type S), and a mix with triple hybrid fiber (0.25% steel fiber type S1+ 0.25% polypropylene fiber + 0.25% steel fiber type S). Fresh (workability and fresh density) and hardened concrete properties (oven dry density, compressive strength, ultrasonic pulse velocity, splitting tensile strength, flexural strength, static modules of elasticity, thermal conductively, and water absorption) were studied. Generally, mono and hybrid (double and triple) fiber reinforced HPLWAC specimens give a significant increase in splitting tensile strength and flexural strength compared with plain HPLWAC specimens. The percentage increases in splitting tensile strength for specimens with mono plastic fiber are, 20.8%, 31.9%, 36.4% and 41%, while the percentage increases in flexure strength are 19.5%, 37%, 33.9% and 34.2% at 7, 28, 60, 90 days age respectively relative to the plain concrete. The maximum splitting tensile and flexure strengths were recorded for triple hybrid fiber reinforced HPLWAC specimens. The percentage increases in splitting tensile strength for triple hybrid fiber reinforced specimens are 19.5%, 37%, 33.9% and 34.2%, while the percentage increases in flexure strength are 50.5%, 62.4. %, 66.8% and 62.2% at 7, 28, 60 and 90 days age respectively relative to the plain concrete specimens.


2011 ◽  
Vol 477 ◽  
pp. 274-279 ◽  
Author(s):  
Yi Xu ◽  
Lin Hua Jiang ◽  
Hong Qiang Chu ◽  
Lei Chen

In this study, the effects of fiber types on the mechanical properties of lightweight aggregate concretes were investigated. Three types of fibers, namely, polypropylene fiber, steel fiber and water hyacinth (Eichhornia crassipes) fiber, and two types of lightweight aggregates, namely, expanded polystyrene and ceramsite were used. The compressive strength and splitting tensile strength of concretes were tested. The results show that both the compressive strength and the splitting tensile strength were improved by adding a reasonable volume of steel fiber and polypropylene fiber into LWAC. The addition of water hyacinth fiber had little effect on the compressive strength of LWAC, while a little increase was observed in the splitting tensile strength.


Fibers ◽  
2019 ◽  
Vol 7 (4) ◽  
pp. 36 ◽  
Author(s):  
Hisham Alabduljabbar ◽  
Rayed Alyousef ◽  
Fahed Alrshoudi ◽  
Abdulaziz Alaskar ◽  
Ahmed Fathi ◽  
...  

The behaviors of the fresh and mechanical properties of self-compacting concrete (SCC) are different from those of normal concrete mix. Previous research has investigated the benefits of this concrete mix by incorporating different constituent materials. The current research aims to develop a steel fiber reinforcement (SFR)‒SCC mixture and to study the effectiveness of different cement replacement materials (CRMs) on the fresh and mechanical properties of the SFR‒SCC mixtures. CRMs have been used to replace cement content, and the use of different water/cement ratios may lower the cost of CRMs, which include microwave-incinerated rice husk ash, silica fume, and fly ash. Fresh behavior, such as flow and filling ability and capacity segregation, was examined by a special test in SCC on the basis of their specifications. Moreover, compressive and splitting tensile strength tests were determined to simulate the hardened behavior for the concrete specimens. Experimental findings showed that, the V-funnel and L-box were within the accepted range for SCC. Tensile and flexural strength increases upon the use of 10% silica fume were found when compared with other groups; the ideal percentage of steel fiber that should be combined in this hybrid was 2% of the total weight of the binder. Overall, steel fibers generated a heightened compressive and splitting tensile strength in the self-compacting concrete mixes.


2013 ◽  
Vol 438-439 ◽  
pp. 290-294 ◽  
Author(s):  
Hong Yuan Huo ◽  
Li Sha Song ◽  
Li Sun ◽  
Chen Jie Cao

Test of basic properties of steel fiber reinforced concrete (SFRC) was carried out to further study the validity of the binary superposition mix proportion method. The strength grades of SFRC were CF40, CF50 and CF60. The key parameters of the study were the fraction of steel fiber by volume, the thickness of cement paste wrapping steel fibers and the water to cement ratio. The workability of fresh SFRC was measured firstly to satisfy the construction requirement. The compressive strength, tensile strength and flexural-tensile strength of SFRC were tested simultaneously. Based on the test data, the changes of above basic properties of SFRC are analyzed in view of the effects of the fraction of steel fiber by volume and the thickness of cement paste wrapping steel fibers. It shows that the optimum thickness of cement past wrapping steel fibers is 0.8mm. The influencing coefficients in formulas for calculating tensile strength and flexural-tensile strength of SFRC specified in the current technical specification are given out.


2014 ◽  
Vol 1065-1069 ◽  
pp. 1985-1989
Author(s):  
Jia Bin Wang ◽  
Di Tao Niu ◽  
Rui Ma ◽  
Ze Long Mi

In order to investigate the carbonation resistance of shotcrete and the mechanical properties after carbonation, the accelerated carbonation test was carried out. The results indicate that the carbonation resistance of shotcrete is superior to that of normal concrete. With the increasing of carbonation depth, compressive strength and splitting tensile strength of shotcrete grew rapidly. The admixing of steel fiber can further improve the carbonation resistance, reduce the carbonation rate, and increase the splitting tensile strength of shotcrete greatly. Besides, based on analyzing the effects of construction technology and steel fiber of concrete for the carbonation resistance, a carbonation depth model for shotcrete was established. Key words: shotcrete; carbonation; steel fiber; mechanical properties


2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
E. Rabiaa ◽  
R. A. S. Mohamed ◽  
W. H. Sofi ◽  
Taher A. Tawfik

This research investigates the simultaneous impact of two different types of steel fibers, nanometakaolin, and nanosilica on the mechanical properties of geopolymer concrete (GPC) mixes. To achieve this aim, different geopolymer concrete mixes were prepared. Firstly, with and without nanomaterials (nanosilica and nanometakaolin) of 0, 2%, 4%, 6%, and 8% from ground granulated blast furnace slag (GGBFS) were used. Secondly, steel fiber (hooked end and crimped) content of (0, 0.5%, 1, and 1.5%) was used. Thirdly, optimum values of nanomaterials with the optimum values of steel fiber were used. Crimped and hooked-end steel fibers were utilized with an aspect ratio of 60 and a length of 30 mm. Geopolymer mixes were manufactured by using a constant percentage of alkaline activator to binder proportion equal to 0.45 with GGBFS cured at ambient conditions. For alkaline activator, sodium hydroxide molar (NaOH) and sodium hydroxide solution (NaOH) were used according to a proportion (Na2SiO3/NaOH) of 2.33. The hardened concrete tests were performed through the usage of splitting tensile strength, flexural, and compressive experiments to determine the impact of steel fibers, nanometakaolin, and nanosilica individually and combined on performance of GPC specimens. The results illustrated that using a mix composed of the optimum steel fibers (1% content) accompanied by an optimum percentage of 6% nanometakaolin or 4% nanosilica demonstrated a significant enhancement in the mechanical properties of GPC specimens compared to all other mixtures. Besides, the impact of using nanomaterials individually was found to be predominant on compressive strength on GPC specimens especially with the usage of the optimum values. However, using nanomaterials individually compared to using the steel fibers individually was found to have approximately the same splitting tensile strength and flexural performance.


2012 ◽  
Vol 424-425 ◽  
pp. 908-911
Author(s):  
Xian Long Luo ◽  
Li Zeng Li ◽  
Hui Zeng Yin

The spayed concrete is blended with steel fiber,which can improve tensile strength and higher resistance to deformation. This method is applied to support underground chamber surrounded by weak wallrock or chamber bearing great load. this paper accounts for the theory of sprayed steel fiber concrete and its application in tunnelling construction.And aslo, its comprehensive economic effect will be emphasized in comparison with jetting concrete net from the aspects of technology,safety and economy.


2013 ◽  
Vol 739 ◽  
pp. 251-254
Author(s):  
Ru Jie Huang ◽  
Chen Shi ◽  
Guo Xin Li

Lightweight aggregate concrete has lower density and lower elasticity modulus, so it has better earthquake resistance. But the low strength limited the application of lightweight concrete. Steel fiber can improve the strength of lightweight aggregate concrete. In this paper, the influences of different lengths of steel fiber on the slump, compressive strength, splitting tensile strength and antiflex cracking strength are investigated. The results show that adding steel fiber reduces the workability of the concrete mixture, but it improved the each strength of light weight concrete and different lengths have the different regularity of effects.


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