scholarly journals Effects of Polypropylene Fiber on the Liquefaction Resistance of Saturated Sand in Ring Shear Tests

2019 ◽  
Vol 9 (19) ◽  
pp. 4078 ◽  
Author(s):  
Yuxia Bai ◽  
Jin Liu ◽  
Zezhuo Song ◽  
Fan Bu ◽  
Changqing Qi ◽  
...  
Keyword(s):  
Polypropylene Fiber ◽  
Fiber Reinforcement ◽  
Fiber Content ◽  
Saturated Sand ◽  
Liquefaction Resistance ◽  
Ring Shear ◽  
Ring Shear Tests ◽  
Ring Shear Apparatus ◽  
The One ◽  
Shear Energy

This study focused on investigating the effects of polypropylene fiber on the liquefaction resistance of saturated sand. We performed a battery of tests with a state-of-the-art ring shear apparatus on fiber-reinforced saturated sand, considering the influences of fiber content and sand density. Two different shearing methods named shear-torque-controlled (STC) and cyclic-torque-controlled (CTC) were considered for carrying out the tests. An energy approach was chosen to evaluate the results, and the fiber reinforcement mechanisms were analyzed. Our test results showed that in STC tests, the shear strength and shearing time of saturated sand increased proportionally to an increase of fiber content and sand density. The cycles required for liquefaction in CTC tests also increase with an increase in sand density and fiber content. The presence of fibers clearly increases the shear energy required for liquefaction. The shear energy increases with an increase in sand density and fiber content. Greater total shear energy is required in specimens with a higher density or larger fiber content. Fiber reinforcement in sand has acted as a spatial network in interlocking soil grains, thereby resulting in the necessity of more energy for overcoming the resistance during the shearing process. After performing the shearing test, the unreinforced specimen with loose structure collapsed totally, and the one with a dense structure collapsed partially, while fiber reinforcement specimens still maintained structural stability.

scholarly journals Cyclic deformation of granular material subjected to moving-wheel loads

2011 ◽  
Vol 48 (5) ◽  
pp. 691-703 ◽  
Author(s):  
Tatsuya Ishikawa ◽  
Etsuo Sekine ◽  
Seiichi Miura
Keyword(s):  
Single Point ◽  
Scale Model ◽  
Small Scale ◽  
Loading Test ◽  
Ring Shear ◽  
Ballasted Track ◽  
Ring Shear Tests ◽  
Wheel Loading ◽  
The One ◽  
Small Scale Model

This paper describes a new testing method to examine the mechanical behavior of railroad ballast subjected to repeated train passages on ballasted track. Two types of cyclic loading tests, namely a single-point loading test and a moving-wheel loading test, were performed with small-scale models of ballasted track. Next, a “multi-ring shear apparatus” was developed as a type of torsional simple shear apparatus, and the applicability of a newly proposed multi-ring shear test to an element test of railroad ballast subjected to moving-wheel loads was examined by comparing the results of multi-ring shear tests with those of small-scale model tests. As a result, it was recognized that cumulative strain obtained from multi-ring shear tests is almost equivalent to the one derived from small-scale model tests. Moreover, it was revealed that the difference between loading methods has a considerable influence on the cyclic plastic deformation of railroad ballast because settlement in a moving-wheel loading test was much larger than the one in a single-point loading test. These results lead to the conclusion that a multi-ring shear test has an excellent applicability to the estimation of deformation behavior of granular materials subjected to moving-wheel loads.

Experimental study on the strength of silty soft soil in beach with polypropylene fiber reinforcement

2020 ◽  
pp. 10-17
Author(s):  
Qi Daozheng ◽  
Gu Cong ◽  
Fu Jiajia ◽  
Wang Yao
Keyword(s):  
Experimental Study ◽  
Compressive Strength ◽  
Shear Strength ◽  
Internal Friction ◽  
Unconfined Compressive Strength ◽  
Fiber Length ◽  
Soft Soil ◽  
Polypropylene Fiber ◽  
Fiber Reinforcement ◽  
Fiber Content

The effects of polypropylene fiber reinforcement on shear strength and unconfined compressive strength of silty soft soil in tidal flats were studied. Through shear test and unconfined compression test, Experimental study was conducted on silty soft soil of allene fiber reinforced beach with 0~0.6% different mass content and 3 ~18m different length. The failure process and mechanism of fiber reinforced soil samples were also discussed. The test results show that: Shear strength (cohesion and internal friction Angle) and unconfined compressive strength increased rapidly in the early stage with the increase of fiber content, and gradually decreased after reaching the peak at a certain content. In this test, the optimal fiber length corresponding to shear strength is 9mm. When the content is less than 0.6%, the optimal content of cohesion is about 0.2%, and the optimal content corresponding to the Angle of internal friction is between 0.2% and 0.3%. Within the range of 18mm fiber length in the experimental study, unconfined compressive strength increased with the increase of fiber length, and the optimal fiber content corresponding to unconfined compressive strength was 0.2%. The main effects of polypropylene fiber reinforcement on soil cohesion and unconfined compressive strength are not obvious.

scholarly journals Multi-Scale Study of The Small-Strain Damping Ratio of Fiber-Sand Composites

Polymers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2476
Author(s):  
Haiwen Li ◽  
Sathwik S. Kasyap ◽  
Kostas Senetakis
Keyword(s):  
Dynamic Properties ◽  
Wide Spectrum ◽  
Damping Ratio ◽  
Polypropylene Fiber ◽  
Small Strain ◽  
Treatment Method ◽  
Fiber Content ◽  
Polypropylene Fibers ◽  
Test Results ◽  
Fiber Reinforced

The use of polypropylene fibers as a geosynthetic in infrastructures is a promising ground treatment method with applications in the enhancement of the bearing capacity of foundations, slope rehabilitation, strengthening of backfills, as well as the improvement of the seismic behavior of geo-systems. Despite the large number of studies published in the literature investigating the properties of fiber-reinforced soils, less attention has been given in the evaluation of the dynamic properties of these composites, especially in examining damping characteristics and the influence of fiber inclusion and content. In the present study, the effect of polypropylene fiber inclusion on the small-strain damping ratio of sands with different gradations and various particle shapes was investigated through resonant column (macroscopic) experiments. The macroscopic test results suggested that the damping ratio of the mixtures tended to increase with increasing fiber content. Accordingly, a new expression was proposed which considers the influence of fiber content in the estimation of the small-strain damping of polypropylene fiber-sand mixtures and it can be complementary of damping modeling from small-to-medium strains based on previously developed expressions in the regime of medium strains. Additional insights were attempted to be obtained on the energy dissipation and contribution of fibers of these composite materials by performing grain-scale tests which further supported the macroscopic experimental test results. It was also attempted to interpret, based on the grain-scale tests results, the influence of fiber inclusion in a wide spectrum of properties for fiber-reinforced sands providing some general inferences on the contribution of polypropylene fibers on the constitutive behavior of granular materials.

scholarly journals Modeling Granular Crushing in Ring Shear Tests: Experimental and Numerical Analyses

2006 ◽  
Vol 46 (2) ◽  
pp. 147-157 ◽  
Author(s):  
Sebastian Lobo-Guerrero ◽  
Luise Vallejo
Keyword(s):  
Numerical Analyses ◽  
Shear Tests ◽  
Ring Shear ◽  
Ring Shear Tests

Experimental evaluation on engineering properties and microstructure of the high-performance fiber-reinforced mortar with low polypropylene fiber content

2021 ◽  
Vol 72 (7) ◽  
pp. 824-840
Author(s):  
Hung Vu Viet ◽  
Cuong Nguyen Tuan ◽  
Duy Nguyen Huu ◽  
Tho Ngo Nguyen Ngoc ◽  
Phuoc Huynh Trong
Keyword(s):  
High Performance ◽  
Polypropylene Fiber ◽  
Cost Effective ◽  
Fiber Content ◽  
Engineering Properties ◽  
Fiber Reinforced ◽  
Cement Mortars ◽  
High Performance Fiber ◽  
New Construction ◽  
Local Materials

Recently, high-performance fiber-reinforced mortar/concrete (HPFRM) has been researched and developed in many fields such as repair, maintenance, and new construction of infrastructure works due to its high strain capacity and tight crack width characteristics. Optimizing the design of mixture proportions and structures using HPFRM is still a complex mechanical and physical process, depending on the design principles, specific site conditions, and their local materials. This study aims to develop an HPFRM with low polypropylene fiber content by using locally available ingredients in Southern Vietnam to address the deficiencies commonly observed in traditional cement grout mortars. Three mixture proportions were prepared with different water-to-binder (w/b) ratios of 0.2, 0.25, and 0.3. Then, the performance of HPFRM was evaluated in both fresh and hardened stages. Additionally, the microstructural characteristics of each mix design were also assessed through scanning electron microscope observation. The experimental results showed that the optimum w/b of 0.25 and a fixed dosage of 0.6% polypropylene fiber produced positive impacts on the rheological, mechanical properties, and also ductility of the high-performance mortar. It was concluded that HPFRMs are promising for cost-effective and sustainable cement mortars.

The Simulation of a Deep Large-Scale Landslide Near Aratozawa Dam Using a 3.0 MPa Undrained Dynamic Loading Ring Shear Apparatus

2014 ◽  
pp. 459-465 ◽  
Author(s):  
Hendy Setiawan ◽  
Kyoji Sassa ◽  
Kaoru Takara ◽  
Toyohiko Miyagi ◽  
Hiroshi Fukuoka ◽  
...  
Keyword(s):  
Dynamic Loading ◽  
Large Scale ◽  
Ring Shear ◽  
Ring Shear Apparatus
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