A cleaner polyurethane elastomer grouting material with high hardening strain for the fundamental rehabilitation: The comprehensive mechanical properties study

The following paper presents a simple, inexpensive and scalable method of production of carbon nanotube-polyurethane elastomer composite. The new method enables the formation of fibers with 40% w/w of nanotubes in a polymer. Thanks to the 8 times higher content of nanotubes than previously reported for such composites, over an order of magnitude higher electrical conductivity is also observed. The composite fibers are highly elastic and both their electrical and mechanical properties may be easily controlled by changing the nanotubes content in the composite. It is shown that these composite fibers may be easily integrated with traditional textiles by sewing or ironing. However, taking into account their light-weight, high conductivity, flexibility and easiness of molding it may be expected that their potential applications are not limited to the smart textiles industry.

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Experimental Study on the Thermal-Mechanical Properties and Degradation of Sleeve Grouting Material at Elevated Temperatures

Journal of Materials in Civil Engineering ◽

10.1061/(asce)mt.1943-5533.0003493 ◽

2021 ◽

Vol 33 (2) ◽

pp. 04020453

Author(s):

Congcong Xue ◽

Chaoxiong Su ◽

Min Yu ◽

Haoming Xu ◽

Jianqiao Ye

Keyword(s):

Mechanical Properties ◽

Experimental Study ◽

Elevated Temperatures ◽

Grouting Material ◽

Thermal Mechanical Properties

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A More Realistic Study on the Mechanical Properties of CFRC Composite Grouting Material under a Long-Term Water Immersion Process

Advances in Materials Science and Engineering ◽

10.1155/2019/2736481 ◽

2019 ◽

Vol 2019 ◽

pp. 1-11

Author(s):

Yao Xiao ◽

Huafeng Deng ◽

Jianlin Li ◽

Eleyas Assefa

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

Carbon Fiber ◽

Water Immersion ◽

Fiber Content ◽

Grouting Material ◽

Bonding Properties ◽

Grouting Materials ◽

Dam Foundations

The long-term effect of water immersion on the mechanical properties of CFRC composite grouting materials was studied by using five different carbon fiber contents (0, 0.25%, 0.50%, 0.75%, and 1.00%). The direct shear and long-term immersion tests were performed based on the specified and optimum values of carbon fiber content, respectively. The results showed the following: (1) the application of carbon fiber significantly improved the shear resistance of CRFC composite grouting material by using “reinforcing” and “anchoring” actions. The shear strength of the specimen was increasing by 5.66%∼43.41% when the carbon fiber content increased from 0.25% to 1.00%. After a comprehensive analysis, the optimum carbon fiber content was found to be 0.75%. (2) The degradation in the compressive and tensile strength of CRFC composite specimens exhibited a consistent trend (i.e., a steep gradient was gradually followed by a gentle slope) under a long-term water immersion process. About 90% of the total degradation in the compressive and tensile strength has occurred in 90 immersion days (i.e., 16.05% and 18.45%, respectively). In comparison, the degradation in the tensile strength (20.05%) was slightly higher than the compressive strength (18.16%). (3) Under the long-term water immersion process: the properties of the specimens were gradually deteriorating, the carbon fibers were gradually reaching a fatigue stage, and the bonding properties of carbon fiber was decreasing, which resulted in a reduction in the compressive and tensile strength. The uniaxial compression failure mode changed from brittle to ductile, and the development of local failure was very noticeable. Based on the findings of this paper, groundwater has a significant impact on the mechanical properties of grouted rock mass such as dam foundations and abutments. Therefore, the degradation in the grouting materials has to be considered in practical cases.

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