scholarly journals The Influence of the Hybridization of Steel and Polyolefin Fiber on the Mechanical Properties of Base Concrete Designed for Marine Shotcreting Purposes

2021 ◽  
Vol 11 (20) ◽  
pp. 9456
Author(s):  
Changjoon Lee ◽  
Andres Salas Montoya ◽  
Hoon Moon ◽  
Hyunwook Kim ◽  
Chulwoo Chung
Keyword(s):  
Steel Fiber ◽  
Mechanical Performance ◽  
Synergetic Effect ◽  
Chloride Ion ◽  
Concrete Specimen ◽  
Hybrid Fiber ◽  
Electrically Conductive ◽  
Chloride Ion Penetration ◽  
Binder Ratio ◽  
Ion Penetration

The present study investigated the influence of the hybridization of steel and polyolefin fiber on the mechanical performance and chloride ion penetration of base concrete designed for marine shotcreting purposes. The purpose of fiber hybridization is to reduce the risk of corrosion that might occur during service life. Sets of hybrid fiber reinforced base concrete, whose water to binder ratio was 0.338, were prepared. The fiber contents in the base concrete were 0.54 and 1.08 vol%, and the volume proportion of polyolefin fiber in the hybrid fiber varied from 0 to 100%. Although the effect of fiber hybridization was not clearly observed from the compressive strength, a synergetic effect which increased both the flexural strength and toughness occurred at a fiber content of 1.08 vol%. The optimum ratio of steel and polyolefin fiber was 50:50. With respect to chloride ion penetration, an increasing amount of steel fiber increased the amount of current passing through the base concrete specimen due to the presence of electrically conductive steel fiber. However, chloride ion diffusivity was not greatly affected by the presence of steel fiber.

scholarly journals Mechanical and Durability Properties of Latex-Modified Hybrid Fiber-Reinforced Roller-Compacted Rapid-Set Cement Concrete for Pavement Repair

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3981
Author(s):  
Su-Jin Lee ◽  
Hyung-Jin Shin ◽  
Chan-Gi Park
Keyword(s):  
Mechanical Performance ◽  
Chloride Ion ◽  
Synthetic Fiber ◽  
Jute Fiber ◽  
Cement Concrete ◽  
Hybrid Fiber ◽  
Blend Ratio ◽  
Chloride Ion Penetration ◽  
Chlorine Ion ◽  
Ion Penetration

This study evaluated the mechanical properties and durability performance of latex-modified hybrid fiber-reinforced roller-compacted rapid-set cement concrete (LMHFRCRSC) for emergency repair of concrete pavement. Experimental parameters included the blend ratio of the hybrid fiber, which comprised natural jute fiber (0–0.2 vol.%) and structural synthetic fiber (0–2 vol.%). The mechanical performance of LMHFRCRSC of various blend ratios was evaluated in terms of compressive, flexural, and splitting tensile strength. Durability assessment included chlorine ion penetration and abrasion resistance measurements. Compressive and flexural strength values of 21 and 3.5 MPa, respectively, were the set targets after 4 h of curing; a compressive strength of 35 MPa, a flexural strength of 4.5 MPa, a splitting tensile strength of 4.2 MPa, and chloride ion penetration of 2000 C or less were required after 28 days of curing. Our test results confirmed that all mix proportions satisfied the target values, regardless of the blend ratio of the hybrid fiber. Specifically, the mechanical performance of the concrete improved as the blend ratio of the structural synthetic fiber increased. With regard to durability, a greater amount of jute fiber, a hydrophilic fiber, enhanced the concrete’s durability. Additionally, incorporating jute fiber of 0.6 kg/m3 provided excellent chlorine ion penetration resistance. The optimal blend ratio for the hybrid fiber was natural jute fiber at 0.6 kg/m3 and structural synthetic fiber at 13.65 kg/m3 (mix: J0.6 + P13.65); with this mix proportion, a chloride ion penetration amount of 1000 C or less and maximum mechanical performance were achieved.

A STUDY ON IMPROVEMENT AND ITS EVALUATION FOR THE SURFACE LAYER OF CONCRETE PLACED WITH PERMEABLE FORM

2012 ◽  
Vol 06 ◽  
pp. 664-669
Author(s):  
RYOICHI TANAKA ◽  
TAKASHI HABUCHI ◽  
TAKAHIKO AMINO ◽  
TSUTOMU FUKUTE
Keyword(s):  
Surface Layer ◽  
Chloride Ion ◽  
Concrete Specimen ◽  
Air Permeability ◽  
Permeability Test ◽  
Carbonation Depth ◽  
Chloride Ion Penetration ◽  
Rebound Number ◽  
Ion Penetration

Permeable form can improve the quality of the surface layer of concrete and can enhance the durability of concrete structures. In this study, the improvement and its evaluation for the surface layer of concrete placed with permeable form were investigated. For these purposes, accelerated carbonation test, chloride ion penetration test, air permeability test, rebound hummer test and water permeability test were conducted using the concrete specimen. As a result, it was found that the air permeability correlates the carbonation depth, chloride ion penetration depth, rebound number and water permeable volume of concrete. Moreover, the possibility that the improvement for the surface layer of concrete can be quantitatively evaluated by air permeability test was shown.

Penetration Behavior of Chloride Ions into Concrete in Coastal Areas

2006 ◽  
Vol 302-303 ◽  
pp. 584-590
Author(s):  
Yoshihiro Masuda ◽  
F.-R. Wu ◽  
S. Nakamura ◽  
S. Sato
Keyword(s):  
Chloride Ion ◽  
Concrete Specimen ◽  
Chloride Ions ◽  
Ion Content ◽  
Exposure Test ◽  
Total Chloride ◽  
Chloride Ion Penetration ◽  
Apparent Diffusion ◽  
Penetration Behavior ◽  
Ion Penetration

Exposure test on chloride ion penetration behavior into Concrete in coastal area was implemented. The distances between concrete specimens and coast were changed in the range from 50 to 150 meters, and water-cement ratios (W/C) were 45, 55, 60 and 65 %. The total chloride ion content at each different depth from surface of concrete specimen was measured at the age of 1, 2, 3, 5, 7, 8 and 10 years. In this paper, apparent diffusion coefficient (D) and chloride ion content on surface of concrete (C0) were calculated by inverse analyses from the measured total chloride ion content, and the chloride ion penetration behavior was simulated using the calculated D and C0. As a result, the chloride ion penetrated in concrete with a W/C of 60 % at a point 50 m from the sea for 10 years was estimated approximately 0.2 kg/m3.

Experimental Research on the Evaluation Method of the Resistance to Chloride Ion Penetration of Autoclaved PHC Pile

2014 ◽  
Vol 629-630 ◽  
pp. 587-592
Author(s):  
Yi Bo Yang ◽  
Zhao Qiong Lai ◽  
Li Tao Ai ◽  
Wen Ying Guo ◽  
Hong Jian Huang ◽  
...  
Keyword(s):  
Quality Control ◽  
Synthesis Method ◽  
Chloride Ion ◽  
Concrete Specimen ◽  
Life Assessment ◽  
Chloride Diffusion ◽  
Chloride Diffusion Coefficient ◽  
Chloride Ion Penetration ◽  
Chloride Migration ◽  
Ion Penetration

The usage of autoclaved PHC pile in chloride environment becomes common, so how to evaluate the resistance to chloride ion penetration of autoclaved PHC pile becomes urgent. This article Compare the resistance to chloride ion penetration of pile and pile concrete specimens based the Rapid Chloride Migration Synthesis Method and RCM. The results show that the Rapid Chloride Migration Synthesis Method is not suitable for pile, RCPT and RCM are suitable for pile; the resistance to chloride ion penetration of the pile inner and outer lateral concrete has a rather large different, so the sample must distinguish the direction when testing. Steel bar has little influence on the resistance to chloride ion penetration of autoclaved PHC pile, and the resistance to chloride ion penetration of pile outer lateral concrete is similar with pile concrete specimen, using pile concrete specimen to test the resistance to chloride ion penetration of autoclaved PHC pile is suitable. The chloride diffusion coefficient values have a good relationship with the electricity value, using the electricity value of square pile concrete specimen as commonly quality control way are suggested. The resistance to chloride ion penetration of pile can test the outer lateral concrete of pile or pile head, using the electricity value as daily quality control method and basis for project acceptance, and using RCM method as life assessment and basis for project acceptance.

scholarly journals Effect of steel fiber on impact resistance and durability of concrete containing nano-SiO2

2021 ◽  
Vol 10 (1) ◽  
pp. 504-517
Author(s):  
Peng Zhang ◽  
Hongsen Zhang ◽  
Guo Cui ◽  
Xiaodong Yue ◽  
Jinjun Guo ◽  
...  
Keyword(s):  
Impact Energy ◽  
Steel Fiber ◽  
Impact Resistance ◽  
Chloride Ion ◽  
Penetration Resistance ◽  
Freeze Thaw ◽  
Chloride Ion Penetration ◽  
The Impact ◽  
Durability Of Concrete ◽  
Ion Penetration

Abstract Impact drop weight tests, rapid chloride migration coefficient tests, single-sided freeze–thaw tests, and mechanical property tests were performed to investigate the effect of the steel fiber (SF) content on the impact resistance and durability of concrete containing nano-SiO2 (NS). A fixed NS content of 3% and six SF contents in a range of 0–2.5% by volume were used. The impact resistance was measured based on the number of blows (N1, N2) and the impact energy. The durability of concrete includes its freeze–thaw resistance and chloride ion penetration resistance, which were appraised by the chloride ion diffusion coefficient (CDC) and relative dynamic elastic modulus (RDM), respectively. The ductility ratio was used to predict the impact resistance of concrete containing NS with different SF contents, and a linear relation between this ratio and the impact energy (R 2 = 0.853) was found. The experimental results indicated that SF could greatly improve the impact resistance of concrete. The addition of 2.0% SF increased N1 and N2 by 106 and 169%, respectively. In addition, an appropriate SF content significantly improved the durability of the concrete, including its frost resistance (especially in the middle and late freezing–thawing cycles) and chloride ion penetration resistance. An SF content of 1.5% was the optimum, decreasing the CDC of nano-concrete by 17.1% and minimizing the RDM loss. Moreover, the 1.5% SF content increased the compressive strength of concrete containing NS by 18.5%, whereas an SF content of 2.0% increased the splitting tensile strength and flexural strength by 77 and 20%, respectively. Furthermore, when the SF content exceeded a certain value, the improvement effect on these properties began to decrease and even became negative.

scholarly journals Prediction of Chloride Ion Penetration of Recycled Aggregate Concrete

2015 ◽  
Vol 18 (2) ◽  
pp. 427-440 ◽  
Author(s):  
Rui Vasco Silva ◽  
Jorge de Brito ◽  
Rui Neves ◽  
Ravindra Dhir
Keyword(s):  
Chloride Ion ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Aggregate Concrete ◽  
Chloride Ion Penetration ◽  
Ion Penetration
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