scholarly journals Mechanical Properties of Hybrid Ultra-High Performance Engineered Cementitous Composites Incorporating Steel and Polyethylene Fibers

Materials ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1448 ◽  
Author(s):  
Yingwu Zhou ◽  
Bin Xi ◽  
Kequan Yu ◽  
Lili Sui ◽  
Feng Xing

This paper presents the authors’ newly developed hybrid ultra-high performance (HUHP) engineered cementitious composite (ECC) with steel (ST) and polyethylene (PE) fibers. From this point on it will be referred to as HUHP-ECC. The volumes of steel and PE fibers were adjusted to obtain different mechanical properties, including compressive strength, tensile, and flexural properties. We found that tensile and flexural properties, including bending strength and ductility indexes, increased with higher PE fiber amounts but reduced with the increased ST fiber volume. Notably, the compressive strength had the opposite tendency and decreased with increases in the PE volume. The ST fiber had a significantly positive effect on the compressive strength. The fluidity of HUHP-ECC improved with the increasing amount of ST fiber. The pseudo strain-hardening (PSH) values for all the HUHP-ECC mixtures were used to create an index indicating the ability of strain capacity; thus, the PSH values were calculated to explain the ductility of HUHP-ECC with different fiber volumes. Finally, the morphology of PE and ST fibers at the fracture surface was observed by an environmental scanning electron microscope (ESEM).

2013 ◽  
Vol 438-439 ◽  
pp. 249-252 ◽  
Author(s):  
Zhe Jin ◽  
Cheng Ya Wang

An experimental study has been conducted to investigate the effect of the fraction of PVA fiber on the mechanical properties of high-performance concrete. The mechanical properties include compressive strength, splitting tensile strength and compressive elastic modulus. On the basis of the experimental results of the specimens of six sets of mix proportions, the mechanism of PVA fiber acting on these mechanical properties has been analyzed in details. The results indicate that there is a tendency of increase in the compressive strength and splitting tensile strength when the fiber volume fraction is below 0.08%, and the compressive elastic modulus of high-performance concrete decreases gradually with the increasing volume fraction of PVA fiber with appropriate content.


2013 ◽  
Vol 275-277 ◽  
pp. 2064-2068 ◽  
Author(s):  
Xiang Gao ◽  
Qing Hua Li ◽  
Shi Lang Xu

High performance nano-binder cementitious composites (HPNCC) are ultra-ductile fiber reinforced cementitious composites with special matrix. The compressive strength and flexural properties of HPNCC containing nano-SiO2 particles were investigated at age of 3d, 7d, 14d and 28d. According to the results, HPNCC exhibited excellent mechanical properties in the test. The compressive strength, flexural strength and first crack strain of HPNCC were all increased obviously at early age except the ultimate strain. In the flexural test, both crack extension width and the number of fine cracks decrease along with the curing age. However, the average crack spacing has no remarkable changes. Nano-SiO2 particles in HPNCC acted as ultra-fine fillers and catalyzers to strengthen the interfacial bond between the matrix and PVA fiber which improved the mechanical properties and would make HPNCC be widely used in the engineering.


2021 ◽  
pp. 002199832110047
Author(s):  
Mahmoud Mohamed ◽  
Siddhartha Brahma ◽  
Haibin Ning ◽  
Selvum Pillay

Fiber prestressing during matrix curing can significantly improve the mechanical properties of fiber-reinforced polymer composites. One primary reason behind this improvement is the generated compressive residual stress within the cured matrix, which impedes cracks initiation and propagation. However, the prestressing force might diminish progressively with time due to the creep of the compressed matrix and the relaxation of the tensioned fiber. As a result, the initial compressive residual stress and the acquired improvement in mechanical properties are prone to decline over time. Therefore, it is necessary to evaluate the mechanical properties of the prestressed composites as time proceeds. This study monitors the change in the tensile and flexural properties of unidirectional prestressed glass fiber reinforced epoxy composites over a period of 12 months after manufacturing. The composites were prepared using three different fiber volume fractions 25%, 30%, and 40%. The results of mechanical testing showed that the prestressed composites acquired an initial increase up to 29% in the tensile properties and up to 32% in the flexural properties compared to the non-prestressed counterparts. Throughout the 12 months of study, the initial increase in both tensile and flexural strength showed a progressive reduction. The loss ratio of the initial increase was observed to be inversely proportional to the fiber volume fraction. For the prestressed composites fabricated with 25%, 30%, and 40% fiber volume fraction, the initial increase in tensile and flexural strength dropped by 29%, 25%, and 17%, respectively and by 34%, 26%, and 21%, respectively at the end of the study. Approximately 50% of the total loss took place over the first month after the manufacture, while after the sixth month, the reduction in mechanical properties became insignificant. Tensile modulus started to show a very slight reduction after the fourth/sixth month, while the flexural modulus reduction was observed from the beginning. Although the prestressed composites displayed time-dependent losses, their long-term mechanical properties still outperformed the non-prestressed counterparts.


Author(s):  
M.A.P Handana ◽  
◽  
Besman Surbakti ◽  
Rahmi Karolina ◽  
◽  
...  

The use of borax solution as a preservative in wood and bamboo materials is well known in the community. A borax solution is an environmentally friendly liquid that can dissolve in water, so it is suitable to be used as a preservative within cold or hot soaking techniques. The ability of borax to resist insects and fungus attacks on bamboo has been proven, but the effect of the solution on the strength of bamboo must also be investigated. This study conducts to investigate the effects of borax and its additives as preservative solutions to the mechanical properties of bamboos. The bamboos preservations were conducted by cold conditions of immersion, while the mechanical properties were performed to understand the effects of preservatives. The result of this study indicated that 30% to 50% borax in the preservative solution is sufficient to provide significant increase in strength for compressive strength, tensile strength, and bending strength of bamboo specimen. From this study, the use of borax solution in preserving the bamboos materials improved the quality of bamboos based on its mechanical properties.


Author(s):  
Haruka Murakami ◽  
Hiromi Fujiwara ◽  
Masanori Maruoka ◽  
Takahumi Watanabe ◽  
Koji Satori

In recent years, as structures become higher, larger, and more durable concrete whose compressive strength of the concrete is 150 N/mm 2 or more have been put to practical use. It is for this reason that it is necessary to develop strengthening materials with equal or better performance. Furthermore, the development of high-performance concrete repair materials is carried out because demand to seismic strengthening and repair increases. In this study, considering these circumstances, it was conducted an experimental study with the aim of developing a repair material using room temperature curing UFC (R-UFC). A binder composition preparation of the R-UFC has excellent fluidity under pressure. It was achieved that high-grade thixotropy, high compressive strength, and high bending strength. It can also be sprayed continuously because of its high thixtoropy. It was confirmed that the sprayed thickness was reached to 20mm by one work. Durability of this R-UFC was investigated and it was confirmed the high sulfate resistance, small drying shrinkage and low salt permeability.


2010 ◽  
Vol 168-170 ◽  
pp. 1325-1329
Author(s):  
Ye Ran Zhu ◽  
Jun Cai ◽  
Dong Wang ◽  
Guo Hong Huang

This paper investigates the mechanical properties (compressive strength, splitting tensile strength and flexural toughness) of polypropylene fiber reinforced self-compacting concrete (PFRSCC). The effect of the incorporation of polypropylene fiber on the mechanical properties of PFRSCC is determined. Four point bending tests on beam specimens were performed to evaluate the flexural properties of PFRSCC. Test results indicate that flexural toughness and ductility are remarkably improved by the addition of polypropylene fiber.


2013 ◽  
Vol 368-370 ◽  
pp. 1052-1055
Author(s):  
Seung Jo Lee ◽  
Jung Min Park

The aim of the study is to improve the understanding of the influence of reinforcing fiber types on the mechanical properties of high performance concretes (HPC) subjected to high temperature. The mechanical properties measured include residual compressive strength, weight reduction ratio, outward appearance property, and failure mode. Nylon, polypropylene, and steel fiber were added to enhance mechanical property of the concretes. After exposure to high temperatures ranged from 100 to 800°C, mechanical properties of fiber-toughened HPC were investigated. For HPC, although residual compressive strength was decreased by exposure to high temperature over 500°C, weight reduction ratio was significantly higher than that before heating temperature.


2011 ◽  
Vol 346 ◽  
pp. 30-33
Author(s):  
Hong Wei Wang

A designed experimental study has been conducted to investigate the effect of polypropylene fiber on the compressive strength and flexural properties of concrete containing silica fume, a large number of experiments have been carried out in this study. The flexural properties include flexural strength and flexural modulus of elasticity. On the basis of the experimental results of the specimens of six sets of mix proportions, the mechanism of action of polypropylene fiber on compressive strength, flexural strength and flexural modulus of elasticity has been analyzed in details. The results indicate that there is a tendency of increase in the compressive strength and flexural strength, and the flexural modulus of elasticity of concrete containing silica fume decrease gradually with the increase of fiber volume fraction.


2012 ◽  
Vol 174-177 ◽  
pp. 1459-1462
Author(s):  
Gui Qiu Huang ◽  
Zhen Huang ◽  
Jing Jiang ◽  
Xue Yuan Deng

This paper focuses on the mechanical properties of carbon fiber cloth reinforced bamboos. Using the carbon fiber cloth to reinforce circularly the bamboo can protect dry bursting of the bamboos and improve its mechanical performances. A series of experiments were carried out to investigate the compressive strength, tensile strength and bending strength of bamboo reinforced with carbon fiber cloth. The mechanical performances of bamboos with and without reinforcing were compared and the efficient reinforcing method was suggested, with such method the compressive strength and bending strength of carbon fiber reinforced bamboos could be increased obviously compared with that of bamboos without reinforcing.


2015 ◽  
Vol 833 ◽  
pp. 48-51 ◽  
Author(s):  
Wei Shi ◽  
Jia Yan Li ◽  
Qi Fan You ◽  
Tong Lu ◽  
Yi Tan

Matrix derived from resin after carbonization in rigid carbon felt thermal insulation has many advantages. The microstructures and properties of these materials were investigated in this paper. Results showed that matrix tend to accumulate at the intersections of fibers. This can improve mechanical properties and have a little influence on thermal conductivities of the composites. The excellent bending strength of 2.66MPa, compressive strength of 0.91MPa and a high thermal conductivity of 0.81W/(m·K) (at 1500°C) with a matrix concentration of 32.7% is achieved. However, high thermal conductivity is harmful for those materials which are used as thermal insulators.


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