Effect of Polypropylene Fibers and Cement on the Strength Improvement of Subgrade Lying on Expansive Soil

Author(s):  
Sikander Zaman Khan ◽  
Zia ur Rehman ◽  
Ammad Hassan Khan ◽  
Sabih Qamar ◽  
Farhan Haider
2013 ◽  
Vol 2013 ◽  
pp. 1-7
Author(s):  
S. S. Shebl ◽  
Ibrahim S. Khalil ◽  
H. Shoukry

This study represents an extension work to investigate the role of ultra fine sand (UFS) in enhancing the mechanical properties of fiber reinforced cementitious compounds. The micro-structural origins were identified by scanning electron microscope (SEM). About 50% of UFS had a diameter of less than 20 μm. Ordinary Portland Cement (OPC) was partially substituted by UFS at 3, 5, 7 and 10% by weight of binder. It was found that as UFS loadings increase, the flexural, compressive, and tensile strengths increased up to about 5% UFS loading by 12.9, 15.7 and 30.1%, respectively, thereafter, a decrease in these properties was observed. This can be attributed to the pozzolanic effect besides the filling effect of UFS resulting in enhancing the interfacial bonds between the sand grains and hydration products that makes the paste more homogeneous and dense. The effect of both short natural and artificial fiber loadings on the structural performance of compounds was also studied. Loadings of 2%, by weight, of short natural date palm leaves’ midribs fibers (DP) and artificial polypropylene fibers (PP) were added to the 5% UFS blended mix. An increase in both flexural and tensile strength was achieved, while a decrease in the compressive strength was observed.


Author(s):  
Nitin Tiwari ◽  
Neelima Satyam

Expansive soil shows dual swell-shrink which is not suitable for the construction. Several mitigating techniques exist to counteract the problem promulgate by expansive clayey soils. This paper explored the penitential mecho-chemical reinforcement of expansive clayey soil to mitigate the effect of upward swelling pressure and heave. The polypropylene fiber is randomly distributed in the soil for mechanical stabilization, and the industrial residual silica fume is used as a chemical stabilizer. The experimental analysis is made in three phases which involved the tests on mechanical reinforced expansive soil using randomly distributed polypropylene fibers with different percentages (0.25%, 0.50%, and 1.00%), and 12mm length. The second phase of experiments carried out on chemical stabilized expansive soil with different percentages (2%, 4% and 8%) of silica and next phase of the experimental focused in the combination of mecho-chemical stabilization of the expansive soil with different combination of silica (i.e., 2%, 4% and 8%) and polypropylene fibers (i.e., 0.25%, 0.50% and 1.00%). Maximum dry density (MDD), optimum moisture content (OMC), liquid limit (LL), plastic limit (PL), plastic index (PI) grain size, and constant volume swelling pressure test were performed on unreinforced and reinforced expansive soil to investigate the effect of polypropylene fiber and silica fume on the engineering properties of expansive clayey soil. The experimental results illustrate that the inclusion of polypropylene fiber has a significant effect on the upward swelling pressure and expansion property of expansive soil. The reduction in the upward swelling pressure and expansion is a function of fiber content. These results also indicated that the use of silica fume caused a reduction in upward swelling potential, and its effect was considerably more than the influence of fiber.


2020 ◽  
Vol 13 ◽  
pp. e00427 ◽  
Author(s):  
Rizgar A. Blayi ◽  
Aryan Far H. Sherwani ◽  
Hawkar Hashim Ibrahim ◽  
Rabar H. Faraj ◽  
Ako Daraei

2021 ◽  
Vol 3 (5) ◽  
Author(s):  
Samson Yonas Aga

AbstractThis paper illustrates application of a locally produced geogrid material for strength improvement of expansive subgrade soil. Samples of black, soft soil predominating the study area were collected from south western parts of Modjo town, inside the rift valley region of central parts of Ethiopia. X-Ray diffraction as well as index property tests were executed to identify and categorize the expansiveness of the highly plastic soft soil. The effects of two locally manufactured geogrid reinforcement materials; namely, polypropylene (PP) and high density polyethylene (HDPE) on the California bearing ratio (CBR) values of the expansive soil have been investigated. The test results indicated that the use of the geogrid reinforcement can significantly improve the bearing capacity of weak subgrade soil. The soaked CBR of the untreated soil sample, which was about 2.98%, was able to be raised to 10.16% and 7.48% by the application of PP and HDPE type of geogrid respectively, that were placed at 0.35H from the top of specimen. The research demonstrated the potential of using locally produced geogrid material for the improvement of weak subgrade soil.


Geosciences ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 377 ◽  
Author(s):  
Nitin Tiwari ◽  
Neelima Satyam

Expansive soil shows dual swell–shrink which is not suitable for construction. Several mitigating techniques exist to counteract the problem promulgated by expansive clayey soils. This paper explored the potential mecho-chemical reinforcement of expansive clayey soil to mitigate the effect of upward swelling pressure and heave. The polypropylene fiber is randomly distributed in the soil for mechanical stabilization, and the industrial residual silica fume is used as a chemical stabilizer. The experimental analysis was made in three phases which involved tests on mechanically-reinforced expansive soil, using randomly distributed polypropylene fibers with different percentages (0.25%, 0.50%, and 1.00%), and which were 12 mm length. The second phase of experiments was carried out on chemical stabilized expansive soil with different percentages (2%, 4%, and 8%) of silica, and the next phase of the experiment focused on the combination of mecho-chemical stabilization of the expansive soil with different combinations of silica (i.e., 2%, 4%, and 8%) and polypropylene fibers (i.e., 0.25%, 0.50%, and 1.00%). Maximum dry density (MDD), optimum moisture content (OMC), liquid limit (LL), plastic limit (PL), plastic index (PI), grain size, and constant volume swelling pressure tests were performed on unreinforced and reinforced expansive soil, to investigate the effects of polypropylene fiber and silica fume on the engineering properties of expansive clayey soil. The experimental results illustrate that the inclusion of polypropylene fiber has a significant effect on the upward swelling pressure and expansion property of expansive soil. The reduction in the upward swelling pressure and expansion is a function of fiber content. These results also indicated that the use of silica fume caused a reduction in upward swelling potential, and its effect was considerably more than the influence of fiber.


2018 ◽  
Vol 7 (1) ◽  
pp. 73-77
Author(s):  
S. Vinodhkumar . ◽  
A. Kabilan . ◽  
A. Kabilan .

Civil engineering structure resting on expansive soil needs more attention since it causes undesirable engineering behavior when the soil comes in contact with water. The areas consisting of expansive soil need a proper stabilization method to solve the site problems faced by the civil engineers. Pavements constructed on such soil shows signs of damage continuously during the service life of the pavement eventually increase the maintenance costs. Stabilization of this soil is a usual practice for improving the strength. In this work an attempt was made on the utilization of Molasses with soil by adding various percentages of 5, 7.5, 10, 12.5 and 15% in soil and accessed their geotechnical behavior for different curing periods. The effects of Molasses treatment on the strength improvement of compacted expansive clays are studied based on Unconfined Compression tests for different curing periods of 0, 7 and 14 days. UCS performed on these mixes and identified that addition of Molasses attained high strength with the increasing percent of Molasses in soil. From the test results, it was observed that the UCS peak value were increases to 160%. From the experimental study, it is observed that the treatment of the expansive soil with the addition of Industrial waste material Molasses is more efficient in subgrade modification and other geotechnical applications.


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