Mechanisms of interfacial bond in steel and polypropylene fiber reinforced geopolymer composites

2016 ◽  
Vol 122 ◽  
pp. 73-81 ◽  
Author(s):  
Navid Ranjbar ◽  
Sepehr Talebian ◽  
Mehdi Mehrali ◽  
Carsten Kuenzel ◽  
Hendrik Simon Cornelis Metselaar ◽  
...  
Keyword(s):  
Polypropylene Fiber ◽  
Fiber Reinforced ◽  
Interfacial Bond ◽  
Geopolymer Composites

scholarly journals Surface Cracking and Fractal Characteristics of Bending Fractured Polypropylene Fiber-Reinforced Geopolymer Mortar

2021 ◽  
Vol 5 (4) ◽  
pp. 142
Author(s):  
Li Li ◽  
Hai-Xin Sun ◽  
Yang Zhang ◽  
Bo Yu
Keyword(s):  
Fractal Dimension ◽  
Crack Length ◽  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Polypropylene Fiber ◽  
Fiber Reinforced ◽  
Fiber Volume ◽  
Surface Cracking ◽  
Fractal Characteristics ◽  
Geopolymer Composites

Fiber is effective in restricting cracks and improving the toughness of geopolymer composites, but few studies have focused on the surface crack characteristics of fiber-reinforced geopolymer composites. In this paper, after flexural tests of polypropylene fiber-reinforced geopolymer mortar, the surface cracking image was collected by a digital camera and cracking information was extract by deep learning. Finally, the cracking and fractal characteristics were specifically discussed. The semantic segmentation network can accurately extract surface cracks for calculating various parameters. The results showed that the mean intersection over union (mIoU) and mean pixel accuracy (mPA) of the cracks are 0.8451 and 0.9213, respectively. Generally, the crack length, width, area, and fractal dimension of the specimen are all increased with the increase in the fiber volume fraction. These crack parameters grow rapidly when the fiber content is small, and the growth of the crack parameters gradually slows down as the fiber volume fraction increases to approximately 1.5%. The highest crack parameter values were found in the geopolymer mortar, with a 0.48 water–binder ratio and 12 mm fiber length. The variation of the bottom crack length and the side crack fractal dimension can be used to represent the overall crack variation patterns. Meanwhile, the crack parameters increase with the increased fiber factor in a quadratic function. Based on these crack parameters, the critical fiber factor and dense fiber factor of polypropylene fiber-reinforced geopolymer mortar were 200 and 550, respectively. They are greater than those of fiber-reinforced Portland cementitious composites. The influence of various crack parameters on the flexural strength is in the order of the crack area, width, length, and fractal dimension.

scholarly journals Long-Term Properties of Different Fiber Reinforcement Effect on Fly Ash-Based Geopolymer Composite

Crystals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 760
Author(s):  
Rihards Gailitis ◽  
Andina Sprince ◽  
Tomass Kozlovskis ◽  
Liga Radina ◽  
Leonids Pakrastins ◽  
...  
Keyword(s):  
Fly Ash ◽  
Steel Fiber ◽  
Polypropylene Fiber ◽  
Fiber Reinforcement ◽  
Polypropylene Fibers ◽  
Fiber Reinforced ◽  
Waste Products ◽  
Geopolymer Composites ◽  
Creep Strains

Geopolymer composites have been around only for 40 years. Nowadays, they are used in buildings and infrastructures of various kinds. A geopolymer’s main benefit is that it is a green material that is partially made by utilizing waste products. The carbon footprint from geopolymer matrix manufacturing is at least two times less than Portland cement manufacturing. Due to the nature of the geopolymer manufacturing process, there is a high risk of shrinkage that could develop unwanted micro-cracks that could reduce strength and create higher creep strains. Because of this concern, a common strategy to reduce long-term strains of the material, such as shrinkage and creep, is to add fiber reinforcement that would constrain crack development in the material. This article aims to determine how various kinds and amounts of different fiber reinforcement affect fly ash-based geopolymer composites’ creep strains in compression. Specimen mixes were produced with 1% steel fibers, 1% polypropylene fibers, 5% polypropylene fibers, and without fibers (plain geopolymer). For creep and shrinkage testing, cylindrical specimens Ø46 × 190 mm were used. The highest creep resistance was observed in 5% polypropylene fiber specimens, followed by 1% polypropylene fiber, plain, and 1% steel fiber specimens. The highest compressive strength was observed in 1% polypropylene fiber specimens, followed by plain specimens, 1% steel fiber specimens, and 5% polypropylene fiber-reinforced specimens. The only fiber-reinforced geopolymer mix with improved long-term properties was observed with 1% polypropylene fiber inclusion, whereas other fiber-introduced mixes showed significant decreases in long-term properties. The geopolymer composite mix with 1% polypropylene fiber reinforcement showed a reduction in creep strains of 31% compared to the plain geopolymer composite.

scholarly journals Assessment of Performance of Fiber Reinforced Geopolymer Composites by Experiment and Simulation Analysis

2019 ◽  
Vol 9 (16) ◽  
pp. 3424 ◽  
Author(s):  
Khoa V. A. Pham ◽  
Tan Khoa Nguyen ◽  
Tuan Anh Le ◽  
Sang Whan Han ◽  
Gayoon Lee ◽  
...  
Keyword(s):  
Steel Fiber ◽  
Simulation Analysis ◽  
Polypropylene Fiber ◽  
Experimental Results ◽  
Fiber Types ◽  
Geopolymer Concrete ◽  
Fiber Reinforced ◽  
Fiber Volume ◽  
Element Analysis ◽  
Geopolymer Composites

In this work, the experimental and simulation analysis of the performance of geopolymer composites reinforced with steel fiber and polypropylene fiber is investigated. By embedding hooked end steel fiber and polypropylene fiber with various volume fractions of 0%, 0.5%, 1%, 1.5% to the geopolymer concrete mixture, the mechanical behavior was enhanced significantly through experimental results. The compressive strength was improved 26% with 0.5% of polypropylene fiber and 46% with 1% of hooked end steel fiber while the increment of splitting tensile strength was 12% and 28%, respectively. The flexural strength of specimens using two fiber types was also improved when compared with the non-fiber geopolymer concrete. The highest increment obtained with 1.5% of fiber volume content was from 26% to 42%. The compressive performance and flexural performance of fiber-reinforced geopolymer concrete were also better than specimens without fiber, with a higher load carrying capacity, higher stress, higher toughness and smaller strain. Using hooked end steel fiber resulted in better mechanical strength than using polypropylene fiber, and the presence of fibers is an important factor related to the strength improvements. A finite element analysis was modeled by the ANSYS program, and this showed that the load–deflection response and crack patterns also agreed quite well with experimental results.

Water-induced changes in strength characteristics of polyurethane polymer and polypropylene fiber reinforced sand

2021 ◽  
Vol 28 (6) ◽  
pp. 1829-1842
Author(s):  
Ying Wang ◽  
Jin Liu ◽  
Yong Shao ◽  
Xiao-fan Ma ◽  
Chang-qing Qi ◽  
...  
Keyword(s):  
Polypropylene Fiber ◽  
Strength Characteristics ◽  
Fiber Reinforced ◽  
Reinforced Sand ◽  
Induced Changes
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