scholarly journals Increase the Strenght of Base and Subbase of Flexible Pavement by adding Fledspar as additive material

2019 ◽  
Vol 2 (2) ◽  
pp. 59
Author(s):  
Gatot Rusbintardjo ◽  
Lisa Fitriyana ◽  
Nur Izzi M. Yusoff ◽  
Arafat Suleiman Yero

The strength and durability of the flexible pavement is highly dependent on the quality of the aggregate material used for base and subbase layers. This is can be understand since  95 percent of the weight-volume of the base and subbase layer is aggregate. Therefore using a good quality and strong base and subbase material is very important. In this paper, which is a report of a reseacrh,  Feldspar is used as stabilizer of base and subbase materlias of flexible pavement. Feldspar  is a group rock-ftant forming tectosilicate minerals that made up about 41% of the earth’s continental crust by weight. 5 to 25% of Feldspar with increment of 5% by weight of the base and also subbase were added. Direct Shear and California Baring Ratio (CBR) test were conducted., beside water content and dry density test. The results of direct shear  test show that cohesion of base and subbase materials decrease from 0,164 kg/cm2 of original base and subbase materials become 0,01 kg/cm2 for base and subbase material after adding with 25% of Feldspar, and angle of inernal friction increase from 47,670 become 49,800. Meanwhile the results of CBR test show that CBR value of base increase from 30% to 86,40%, as well as for subbase increase from 21,50% to 87,30% after adding with 15% of Feldspar. It can be concluded that adding aggregate of base and subbase with Feldspar the strenght improve signicantly, and the influence is the strengthening of the base and subbase layers.

Soil stabilization is the process which involves enhancing the physical properties of the soil in order to improve its strength, durability etc. by blending or mixing with additives. The different types of method used for soil stabilization are: Soil stabilization with cement, Soil stabilization with lime, Soil stabilization using bitumen, Chemical stabilization and a new emerging technology of stabilization by Geo textiles and Geo synthetic fibers. In this study, we are making use of Steel fibers as geo synthetic material for stabilization of soil. With the introduction of Steel fibers to the soil the CBR values will improve and thickness of pavement layer also gets reduced. It also reduces the intensity of stress on subgrade. Steel fibers is such a geosynthetic material which is effectively accessible, ecofriendly and furthermore savvy. With the use of soil adjustment strategy in development the general expense gets diminished when contrasted with the normal technique for development. The Highway Research Board (HRB) order of the dirt strata like dark cotton soil and sedu soil is finished utilizing appropriate examining system, for example, Core Cutter Method. To decide the attributes like Grading by Sieve Analysis, Atterbergs Limits i.e Liquid farthest point utilizing Cone Penetration Method and Casagrande Method, Plastic breaking point by rolling the example to 3mm breadth string, Shrinkage limit utilizing Shrinkage mechanical assembly, Optimum Moisture Content and Maximum Dry Density utilizing Standard Proctor Test and furthermore California Bearing Ratio by leading CBR test. The pavement thickness was designed using pavement design catalogues published by IRC SP:20-2002. The estimation for the road is done by considering the item such as Jungle Cutting, Earthwork Excavation for Roadway and Drains, compacting and grading etc., as per SR 2016-17, PW, P and IWT circle Dharwad and suggestion of specification for the mixture of Steel fibers as Geo Synthetic material for stabilization using CBR value by CBR Test and Shear strength using Unconfined Compression Test. The different tests were conducted in order to determine the different characteristics and properties of the black cotton soil and obtained with following results. The liquid limit of the soil with addition of Steel fibers was found to be decreasing when compared to liquid limit of soil alone. The plastic furthest reaches of the dirt diminished with the expansion of filaments. The shrinkage furthest reaches of the dirt was expanded with increment in strands. The MDD of the dirt with expansion of Steel filaments by weight of soil is observed to increment upto 0.75% after that it diminishes and the comparing OMC is diminished with expansion of strands. The shear quality of soil diminished significantly with expansion of strands. The CBR estimation of the dirt expanded significantly. The distinctive tests were led so as to decide the diverse qualities and properties of the sedu soil and acquired with following outcomes. The fluid furthest reaches of the dirt alone was observed to be 36.5%. The MDD of the dirt with expansion of 0.25%, 0.5% Steel strands by weight of soil is observed to be diminished by 0.83% and 0.75% , 1.0% Steel filaments by weight of soil is observed to be expanded by 0.11 % and 16.98% separately and the relating OMC is diminished by 15.62%, 21.87% and 33.75% individually. The shear quality of the dirt with the expansion of 0.25%, 0.5%, 0.75% and 1% of Steel strands is observed to be diminished by 38.57%, 38.57%, 35.25% and 5.85%. The CBR estimation of the dirt with expansion of 0.25%, 0.5%, 0.75% and 1.0%, Steel filaments by weight of soil is observed to be expanded. From the restricted research center investigation directed we reasoned that the 0.75% of Steel fiber can generously improve the properties of Black cotton soil. Furthermore, in this way 0.75% of Steel fiber is the ideal fiber content for dark cotton soil. The design thickness of flexible pavement before stabilization is obtained as 450mm and after stabilization is obtained as 250mm.The estimated cost for constructing flexible pavement before stabilization of soil is obtained as 4018050 Rs /Km and after stabilization of soil is obtained as 3721894Rs/Km. The estimated cost after stabilization is found to be decreased by 7.37%.


2013 ◽  
Vol 446-447 ◽  
pp. 1441-1447
Author(s):  
Meng Yun Huang ◽  
Jun Lai Xiong ◽  
Ji Bing Tang ◽  
Chi Long

This paper ananlyzes and contrasts the direct shear test of the expansive soil with different weathered sand dosage (mass ratio) and different lime dosage (mass ratio) in the case of the expansive soil with some water content and dry density .And try to analyzes and researches the impact of expansive soil improved by weathered sand and lime shear strength index . The direct shear test by the expansive soil mixed with different proportions of weathered sand and lime can be concluded that: mixing the weathered sand to improve the shear strength of expansive soil is effective, and cohesion gradually decreases with the increase of doped proportion of sand and the angle of internal friction first increases with the increase of doped proportion of sand and then decreases ;mixing of lime is effective to improve the shear strength of expansive soil, and cohesion gradually decreases with the increase of doped proportion of lime and angle of internal friction first increases and then decreases with the increase of doped proportion of lime. The shear strength of improved expansive soil can meet the subgrade filling with soil standards and at the same time the expansive soil improved by weathered sand and lime reduces the amount of lime and reduce project cost when to achieve the same shear strength standards.


2021 ◽  
Vol 896 ◽  
pp. 165-172
Author(s):  
Jordy Frank Viso Chachayma ◽  
Jhian Franco Torres Alvarez ◽  
Gary Durán Ramírez ◽  
Carlos Mario Fernández Díaz

The purpose of this research is to improve the parameters of shear strength in granular volcanic soil, by adding a percentage of Portland type I cement. The first step for this research was to classify the soil through a Granulometry test, according to the Unified Soil Classification System (USCS), the result was considered as a poorly graded sand with gravel also considered by The American Association of State Highway and Transportation Officials (AASHTO) as “A-1-b”. In addition, the compaction curve of the volcanic soil has a Maximum Dry Density (MDD) of 1.21 kg/cm2 and an optimum moisture content of 17.8%. Also, the friction angle of 33.5° and a cohesion of 0 kg/cm2, and the results of the Direct Shear Test indicate the Residual Stresses of 0.63, 1.34 and 2.65 kg/cm2 according to the Normal Stresses 1, 2 and 4 kg/cm2, respectively. The second step was to apply a Modified Proctor Test as following: one sample for natural soil and four samples adding 3%, 5%, 7% and 9% of cement. Finally, applied the Direct Shear Test: one sample for natural soil and three samples adding 3%, 5%, and 7% of cement after 7 days of curing, then three more samples are taken adding 3, 5% and 7% of cement at 14 days of curing. The results of the Modified Proctor Test of the volcanic soil with the addition of 5% cement has a maximum peak of a Maximum Dry Density of 1.33 kg/cm2 and with an Optimal Moisture Content of 22.7%, improved the MDD by 10% in regard to the natural soil. And the results of the Direct Shear Test shown in each sample an increase from 14.6% to 79.1% in the friction angle in comparison with the natural soil from 25.8% to 161.5% in shear strength. Likewise, the behavior of the volumetric deformation is shown, presenting a greater contraction when a normal stress of 1 kg/cm2 is applied and a greater expansion when a normal stress of 4 kg/cm2 is applied. Also, the volcanic soil at 7 days of curing with 7% cement addition increases its resistance by 67.34% and the volumetric variation decreases by 50% and the volcanic soil at 14 days of curing with 5% addition of cement increases its resistance by 103.40% and the volumetric variation decreases by 25%.


2021 ◽  
Author(s):  
S M Nazmuz Sakib

Soil is main part of every building and structure, without soil no structure could stand up. Soil plays a vital role in the constructure of every structure. If soil is strong in shear strength the building above it will also safe from failure/collapse. So, strength of soil is necessary is the construction of foundation, piers, dams, roads and multistory buildings.To increase the strength of soil we have different choices as to replace the weak soil with the strong soil, or to add other materials in soil to increase its strength like cement, lime etc. This study helps in increasing the shear strength of soil by using brick dust and coir fiber which are waste material but can provide sufficient strength.We use the clayey soil from Nandipur, which is weak in nature. Brick dust obtain from a kiln in Faisalabad and coir fiber which are easily available and economical. Direct shear test is performed to find shear strength and its parameters, CBR is performed to find the bearing capacity of soil and Modified proctor test is used to find out the optimum moisture content and maximum dry density of soil. We perform direct shear test at different percentages of brick dust to find optimum percentage of brick dust and then at this optimum brick dust percentage we vary the percentage of coir fiber to find its optimum value and also CBR for the varying percentage of coir fiber.


2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Yanhui Cheng ◽  
Weijun Yang ◽  
Dongliang He

Structural plane is a key factor in controlling the stability of rock mass engineering. To study the influence of structural plane microscopic parameters on direct shear strength, this paper established the direct shear mechanical model of the structural plane by using the discrete element code PFC2D. From the mesoscopic perspective, the research on the direct shear test for structural plane has been conducted. The bonding strength and friction coefficient of the structural plane are investigated, and the effect of mesoscopic parameters on the shear mechanical behavior of the structural plane has been analyzed. The results show that the internal friction angle φ of the structural plane decreases with the increase of particle contact stiffness ratio. However, the change range of cohesion is small. The internal friction angle decreases first and then increases with the increase of parallel bond stiffness ratio. The influence of particle contact modulus EC on cohesion c is relatively small. The internal friction angle obtained by the direct shear test is larger than that obtained by the triaxial compression test. Parallel bond elastic modulus has a stronger impact on friction angle φ than that on cohesion c. Under the same normal stress conditions, the shear strength of the specimens increases with particle size. The shear strength of the specimen gradually decreases with the increase of the particle size ratio.


2013 ◽  
Vol 353-356 ◽  
pp. 735-739
Author(s):  
Xiao Ming Zhang ◽  
Shu Wen Ding ◽  
Shuang Xi Li

Development of slope disintegration is close to soil mechanic characteristics such as shear strength indices. Soil grain diameter and water content were tested. Soil direct shear test was conducted to analyze the relationship between shear strength indices and the influencing factors. The experimental data indicate that clay content and the range affect soil cohesion value and the scope. Soil cohesion increases with bulk density before 1.6g/cm3. But it decreases when the bulk after that. The results could provide a scientific basis for control of slope disintegration.


2012 ◽  
Vol 569 ◽  
pp. 451-454 ◽  
Author(s):  
Ya Ming Tang ◽  
Yang Tian

In order to test the reducing adhesion and resistance effect of bionic metal non-smooth surface, the direct shear test is experimented on a kind of bionic dredging tools with typical soil and bionic concave pit-like metal surface.The relation of shear force and shear displacement on a certain pressure is presented. The result will help to design the structure of cutting soil tools’ surfaces with less adhesion and resistance.


Author(s):  
P.R. Kalyana Chakravarthy ◽  
R. Rakesh ◽  
T. Kiran ◽  
S. Sivaganesan ◽  
A. Parthiban

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