scholarly journals Effect of different PVA and steel fiber length and content on mechanical properties of CaCO3 whisker reinforced cementitious composites

2019 ◽  
Vol 69 (336) ◽  
pp. 200 ◽  
Author(s):  
M. Cao ◽  
C. Xie ◽  
L. Li ◽  
M. Khan
Keyword(s):  
Mechanical Properties ◽  
Crack Resistance ◽  
Fiber Length ◽  
Large Deflection ◽  
Steel Fiber ◽  
Flexural Behavior ◽  
Cementitious Composites ◽  
Hybrid Fiber ◽  
Pva Fiber ◽  
Fiber Reinforced Cementitious Composites

In this paper, calcium carbonate (CaCO3) whisker as a fiber reinforcement is mixed with steel and PVA fiber to form a multiscale hybrid fiber reinforced cementitious composites (MHFRCC). ASTM standard and post-crack strength techniques are performed to evaluate the mechanical properties of MHFRCC. The 1.25 % long steel fiber, 0.55 % short PVA fiber and 2.0 % CaCO3 whisker specimens showed the best flexural behavior before L/600 deflection. However, 1.5 % long steel fiber, 0.4 % long PVA fiber and 1.0 % CaCO3 whisker specimens presented better crack resistance after L/600 deflection. It is revealed that flexural parameters increase as comprehensive reinforcing index increase. The result showed that the CaCO3 whisker and short PVA fiber provided crack resistance effect at micro-scale and mainly play a dominate role in inhibiting micro-cracking. However, long steel fiber and long PVA fiber showed a better bridging effect of macro cracks at a large deflection.

scholarly journals Study on Mechanical Properties and Constitutive Equation of Hybrid Fiber Reinforced Cementitious Composites Under Static Loading

2016 ◽  
Vol 10 (1) ◽  
pp. 482-491 ◽  
Author(s):  
Huixian Yang ◽  
Jing Li ◽  
Yansheng Huang
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Elastic Modulus ◽  
Steel Fiber ◽  
Cementitious Composites ◽  
Peak Strain ◽  
Fiber Reinforced ◽  
Hybrid Fiber ◽  
Stress Strain ◽  
Fiber Reinforced Cementitious Composites

The Quasi-static mechanical properties of hybrid fiber (steel fiber and Polyvinyl alcohol (PVA) fiber) reinforced cementitious composites (HFRCC(SP)) were investigated by compressive and tensile experiments. The compressive strength, peak strain, elastic modulus and tensile strength are studied as compared with that of engineered cementitious composite (ECC). Study results indicate that steel fibers can improve the compressive and tensile strength of HFRCC(SP) but the peak strain of HFRCC(SP) decreases. The formulas modified based on codes are proposed to calculate compressive peak strain, elastic modulus and tensile strength. The relationship between tensile strain at peak load and tensile strength of HFRCC with different volume fractions of polyethylene fiber and steel fiber were studied and the tensile stress-strain relation was presented. The parameters k1 and k2 of constitutive formulas for fiber reinforced high strength concrete presented by Mansur are modified to describe the stress-strain curve of HFRCC(SP), the modified formulas show good agreement with the experimental results.

Experimental Study on Mechanical Properties of PVA Fiber Reinforced Tailings Cementitious Composites

2012 ◽  
Vol 598 ◽  
pp. 618-621 ◽  
Author(s):  
Wen Bo Bao ◽  
Cheng Hong Wang ◽  
Shao Feng Zhang ◽  
Zhi Qiang Huang
Keyword(s):  
Fiber Length ◽  
Iron Ore ◽  
Cementitious Composites ◽  
Fiber Reinforced ◽  
Flexural Test ◽  
Multiple Cracking ◽  
Iron Ore Tailings ◽  
Mix Proportion ◽  
Pva Fiber ◽  
Fiber Reinforced Cementitious Composites

A type of ecological engineered cementitious composites, which use iron ore tailings to replace fine grinding quartz sand in PVA fiber reinforced cementitious composites, was developed. The flexural strength and toughness of this material were studied by four-point flexural test with samples of beam and sheet. The results show that the fiber reinforced tailings cementitious composites exhibit the characteristics of multiple cracking, high ductility and flexural toughness. The studies indicate that the mix proportion and the fiber length have a significant influence on the properties of this material, particularly for tensile toughness.

scholarly journals Effect of hybrid fibers, calcium carbonate whisker and coarse sand on mechanical properties of cement-based composites

2018 ◽  
Vol 68 (330) ◽  
pp. 156 ◽  
Author(s):  
M. Cao ◽  
L. Li ◽  
M. Khan
Keyword(s):  
Mechanical Properties ◽  
Calcium Carbonate ◽  
Flexural Strength ◽  
Steel Fiber ◽  
Optimization Procedure ◽  
Coarse Sand ◽  
Flexural Behavior ◽  
Hybrid Fibers ◽  
Flexural Performance ◽  
Pva Fiber

Nowadays researchers are developing a new hybrid fiber reinforced cement-based composites (HyFRCC). The new HyFRCC can restrain micro-cracking, improves compressive and flexural performance of beams by addition of calcium carbonate (CaCO3) whisker, polyvinyl alcohol (PVA) fiber and steel fiber. In this work, a mix optimization procedure is shown for multi-scale HyFRCC, with steel, PVA fiber and CaCO3 whisker. The new HyFRCC is explored with addition of coarse sand to further improve its mechanical properties. Additionally, the flexural performance of beam and slabs has been investigated to optimize sand gradation and fiber combination in new HyFRCC. The compressive strength, flexural strength, flexural behavior, flexural toughness, equivalent flexural strength and deflection-hardening behavior of beams and slabs are improved with optimized content of sand gradation, fibers and CaCO3 whisker. The HyFRCC slab with 1.5% steel fiber, 0.4% PVA fiber, 1% CaCO3 whisker and optimized coarse sand showed overall best properties.

scholarly journals High Temperature Flexural Deformation Properties of Engineered Cementitious Composites (ECC) with Hybrid Fiber Reinforcement

2020 ◽  
Vol 2 (2) ◽  
Author(s):  
Zhihui YU ◽  
Zhen YUAN ◽  
Chaofan XIA ◽  
Cong ZHANG
Keyword(s):  
High Temperature ◽  
Flexural Strength ◽  
Room Temperature ◽  
Steel Fiber ◽  
Cementitious Composites ◽  
Fiber Reinforced ◽  
Hybrid Fiber ◽  
Temperature Exposure ◽  
Pva Fiber ◽  
Strength And Toughness

Engineered Cementitious Composites (ECC) is a class of high-performance fiber reinforced composites with ultra-ductility designed based on micromechanics, and it has been developed for increasing application in the construction industry during recent decades. The properties of ECC at room temperature have been tested and studied in depth, however, few studies focus on its performance after high temperature that is one of the worst conditions to ECC. To investigate the change tendency and mechanism for the high temperature flexural properties of hybrid fiber reinforced ECC and the feasibility of calcium carbonate whisker to reduce the cost of ECC materials, polyvinyl alcohol fiber (PVA) reinforced strain hardening cementitious composites (PVA-ECC), steel fiber + PVA fiber reinforced ECC (defined as HyFRECC-A) and steel fiber + PVA fiber + CaCO3 whisker reinforced ECC (defined as HyFRECC-B) subject to room temperature and 200 ℃, 400 ℃, 600 ℃, 800 ℃ elevated temperature exposure were experimentally compared. The results indicate that equally replacing PVA fibers by steel fibers degraded the flexural hardening ability of PVA-ECC at room temperature, while the addition of appropriate amount of CaCO3 whisker improved the flexural strength, toughness and flexural hardening behavior. The elevated temperature posed a significant effect on the flexural strength and toughness of the three types of ECCs. Flexural deflection hardening behavior of the three types of ECCs was eliminated after high temperature exposure. Flexural strength and toughness of PVA-ECC presented an exponential decay along with the increase of temperature. The addition of steel fiber slowed down the decay rate. Although the use of CaCO3 whisker increased the post-temperature flexural strength and toughness of HyFRECC-B, the decay rate was not further decreased.

scholarly journals Flexural Behavior of Reinforced Concrete Beams Reinforced with 3D-Textile Composite Fiber

2020 ◽  
Vol 26 (7) ◽  
pp. 127-144
Author(s):  
Mays R. Abdulghani ◽  
Dr. Ahmed S. Ali
Keyword(s):  
Mechanical Properties ◽  
Reinforced Concrete ◽  
Steel Fiber ◽  
Volume Fraction ◽  
Main Idea ◽  
Composite Fiber ◽  
Reinforced Concrete Beams ◽  
Flexural Behavior ◽  
Textile Fiber ◽  
Textile Composite

Normal concrete is weak against tensile strength, has low ductility, and also insignificant resistance to cracking. The addition of diverse types of fibers at specific proportions can enhance the mechanical properties as well as the durability of concrete. Discrete fiber commonly used, has many disadvantages such as balling the fiber, randomly distribution, and limitation of the Vf ratio used. Based on this vision, a new technic was discovered enhancing concrete by textile-fiber to avoid all the problems mentioned above. The main idea of this paper is the investigation of the mechanical properties of SCC, and SCM that cast with 3D AR-glass fabric having two different thicknesses (6, 10 mm), and different layers (1,2 layers). As well as micro-steel fiber with 1.25% volume fraction was used. Sixteen rectangular reinforced concrete beam specimens have been tested to study the behavior of their flexural strength. The results concluded that utilizing 3D-TFs with mortar mixture gave significantly higher enhancement for the load-carrying capacity than the concrete mixture. The utilization of 3D-TFs and micro-steel fiber together in the SCM mix gave better results. The stiffness of the specimens was improved with increasing the thickness and the number of textile fiber layers.

Study on the Mechanical Properties of High Performance Hybrid Fiber Reinforced Cementitious Composite (HFRCC) under Impact Loading

2014 ◽  
Vol 629-630 ◽  
pp. 79-84 ◽  
Author(s):  
Hui Xian Yang ◽  
Jing Li ◽  
Yan Sheng Huang
Keyword(s):  
Impact Loading ◽  
Material Properties ◽  
High Performance ◽  
Steel Fibers ◽  
Cementitious Composites ◽  
Peak Strain ◽  
Fiber Reinforced ◽  
Hybrid Fiber ◽  
Dynamic Material Properties ◽  
Fiber Reinforced Cementitious Composites

The dynamic material properties of high performance hybrid fiber reinforced cementitious composites (HFRCC) with various volumetric fractions of steel and polyvinyl alcohol (PVA) fibers were studied by the Split Hopkinson Press Bar (SHPB) test. The results show that HFRCC with higher volumetric fraction of steel fibers are more sensitive to stain rate and the dynamic compressive strength increase more prominently with the strain rate increasing, but peak strain shows the opposite trend. The PVA fibers increase the ductility of HFRCC more effectively than steel fibers. Compared to PVA fiber reinforced cementitious composites (FRCC), HFRCC present better dynamic material properties under impact loading.

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