scholarly journals Study on Compaction Characteristics and Construction Control of Mixtures of Red Clay and Gravel

2018 ◽  
Vol 2018 ◽  
pp. 1-8
Author(s):  
Biao Zeng ◽  
Lin-feng Wang ◽  
Yun Tian ◽  
Tao-rui Zeng ◽  
Bing Li

Red clay cannot be used as embankment filler directly due to its water-sensitive property. Gravel is usually added into red clay to enhance its performance in engineering practice. In order to investigate the influence of mixtures of red clay and gravel on the road performance, gravitational compaction experiment of red clay and vibratory compaction experiment of mixtures of red clay and gravel were conducted, respectively. The results indicate that compaction curves of red clay have double peak; the second peak is the real maximum dry density, and its corresponding moisture content is the optimal moisture content. The dry density of mixtures of red clay and gravel is influenced by the content of gravel, vibration frequency, and vibration time. The optimal content of gravel is 30%, the best vibration frequency is 45 Hz, and the optimal vibration time is 5 minutes for the mixtures of red clay and gravel in this study. The effectiveness of optimal content of gravel and optimum vibration parameters was confirmed by a CBR test. According to the compaction experiment results and actual situation in the field, a suitable construction method of subgrade using the mixtures of red clay and gravel was put forward. The feasibility of this method was also confirmed by postconstruction deformation data of the field test embankment.

Author(s):  
M.A Tijani ◽  
S.O.A Olawale

Ede to Akoda is a trunk B-road built over 30 years ago. It has been in despicable condition leading to fatal accidents and loss of life and properties that impacted negatively on the community. This study investigated the flexible pavement failure along the road in order to ascertain the possible causes of its failure. The methodology adopted covered reconnaissance survey, assessment of the physical condition of the road and soil investigation of subgrade. The result of reconnaissance survey revealed that the surface wearing course has degraded extensively. The physical inspections showed that considerable segment of the drainage facilities has collapsed or totally blocked allowing extensive ponding of rain water on the road surface. The pot holes were deep and widespread in most places and the road is near total collapse. The result of soil investigation revealed that natural moisture content, specific gravity, liquid limit, plastic limit, plastic index, maximum dry density and optimum moisture content were within the specifications of the Federal Ministry of Works and Housing limits (FMWH). However, the California bearing ratio values were less than minimum 10% stated in the specifications, this suggests the nature of subgrade soil as a possible cause of failure of road pavements along Ede-Akoda Road, Nigeria. It is recommended that further research be conducted on other structures of the flexible pavement to better ascertain the causes of the studied road failure.


Author(s):  
Simeon O Odunfa ◽  
Adebayo O. Owolabi ◽  
Peter O. Aiyedun ◽  
Obanisola M. Sadiq

Pavement failure has contributed immensely to loss of lives, disruption to normal daily activities and increase amount of money being spent on maintenance annually. One of the causes is associated with inadequate investigations on subgrade materials. This study aimed at examining the geotechnical parameters as factors of pavement failure along Lagos–Ibadan Expressway. Samples were collected at the failed and stable portions on some selected road segments and subjected to laboratory tests including Natural Moisture Content (NMC), Linear Shrinkage(LS), particle size distribution and California Bearing Ratio(CBR). The NMC along the failed sections was on the high side (ranged from 13.11% to 26.89%) compared with the stable sections (ranged from 11.11% to 16.40%). Most of the tested soils have percentage passing 0.075mm sieve more than 35% maximum required by the Federal Ministry of Works and Housing for subgrade materials. The maximum dry density(MDD) for the samples at failed and stable sections ranged from 1550 kg/m3 to 1860 kg/m3; 1650 kg/m3 to 1980 kg/m3 respectively while the Optimum Moisture Content(OMC) ranged from 8.30% to 20.30%. The soaked CBR values ranged from 2% to 17% while the unsoaked values ranged from 4% to 25%. The increase in NMC along the failed portions could be as a result of high water table along these sections. Some of the materials at failed locations had values of LS > 8% which suggests high susceptibility to shrinkage and swelling which results in differential settlement and contributed to pavement failure along these sections of the road. Keywords: Geotechnical, Pavement failures, subsurface investigations, Expressway, subgrade materials.


2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Ubido Oyem Emmanuel ◽  
Igwe Ogbonnaya ◽  
Ukah Bernadette Uche

AbstractInvestigation into the cause of road failure has been carried out along a 60 km long Sagamu –Papalanto highway southwestern Nigeria. Geochemical, mineralogical, geotechnical and geophysical analyses were conducted to evaluate the cause of failure along the study area. The results of the laboratory tests showed that the percentage amount of fines ranges from 12 to 61.3%, natural moisture content from 6.8 to 19.7%, liquid limit in the range of 25.1–52.2%, linear shrinkage between 3.96 to 12.71%, plastic limit ranges from 18.2–35%, plasticity index ranges from 5.2 to 24.6%, free swell in the range from 5.17–43.9%, maximum dry density ranges from 1.51–1.74 g /cm3, specific gravity ranges from 2.52–2.64 and CBR between 3 and 12%. The Cone Penetrometer Test (CPT) shows a resistance value of 20–138 kgf/cm2. The major clay mineral that is predominant in the studied soil is kaolinite. The major oxides present are SiO2, Al2O3, Fe2O3, K2O, Na2O, MgO and CaO. The result of the 2D Electrical Resistivity Imaging revealed a low resistivity values for profile 2 and 3 ranging from 100 Ωm – 300 Ωm, between a distance of 20 m – 240 m along the profile to a depth of 7.60 m and a low resistivity value ranging from 50 Ωm – 111Ωm, between a distance of 80 m − 120 m along the profile to a depth of 15 m. It was concluded that the low CBR, low MDD and the class of subsoils namely A-26, A-7, A-2-7 (clayey soils) which were identified are responsible for the cause of failure experienced in the study area. These makes the soils unsuitable as road construction materials and hence, there is need for stabilization during the reconstruction and rehabilitation of the road.


The aim of the present study is to determine the physical and geotechnical characteristics of municipal solid waste (MSW) from an open dump site located in Una town, Himachal Pradesh (India) for the analysis of settlement and structural stability of landfill. Degraded waste was tested for different time intervals ranging from 6 months to 6 years. The physical characterization and the geotechnical tests were performed to determine the composition and the engineering properties of MSW respectively. The presence of moisture content in the fresh waste was 49.5±1.05% but for the degraded (or old) waste it varied between 39.8 to 51.6%. The specific gravity of fresh and old waste varied between 1.83±0.05 and 1.85 for 6 months old waste and 2.28 for 5-6 years old degraded waste respectively. The maximum dry density (MDD) was observed to be 4.28 kN/m2 for fresh waste at the optimum moisture content (OMC) of 78.1% and 4.47 kN/m3 for 6 months old waste and 6.25 kN/m3 for the degraded waste of 5-6 years at 80.2, 85.4% of OMC respectively. The hydraulic conductivity (k) of MSW was found to be decreasing with the degradation of MSW and the overburden pressure whereas the shear strength increased along with the degradation of the waste. The cohesion (c) and angle of internal friction (φ) increased respectively from 31.2 kPa(fresh) to 38 kPa(degraded) and 14° to 22° with the increase in waste degradation. The compression ratio of fresh waste was within the ranges of 0.19-0.29 and for degraded MSW it varied between 0.12 for 6 months old waste and 0.17 for 5-6 years old degraded waste respectively.


2021 ◽  
Vol 9 (1) ◽  
pp. 16-20
Author(s):  
Iyad Alkroosh ◽  
Ali Al-Robay ◽  
Prabir Sarker ◽  
Saif Alzabeebee

This paper investigates the influence of sand content on the mechanical behavior of a low plasticity clay that collected from south of Iraq (Sumer town). Samples have been prepared with sand contents of 0%, 10%, 20%, 30%, and 40% of the clay weight. Standard Proctor and unconfined compression tests have been carried out and the optimum moisture content, maximum dry density, and undrained shear strength have been determined. The results show a gradual increasing trend of the maximum dry density with the increase of the sand content up to 30%. The highest dry density reaches 1.90 g/cm3 corresponding to an optimum moisture content of 12%. In addition, this paper shows that the undrained shear strength is inversely proportional to the increase of the percentage of sand. The results of this work provide a useful addition to the literature regarding the behaviour or low plasticity clay-sand mixture.


2021 ◽  
pp. 3417-3427
Author(s):  
Amera I. Hussain Hussain ◽  
Ibraheem I. Ibraheem

      In this research, a geotechnical assessment was conducted for clay of the Gercus Formation to determine its suitability for embankment dams. The selected area is located in the north of Iraq. Six samples were collected from two sites in Dokan (Sulaimaniyah) and Haibat Sultan mountain (Koysinjaq), three samples each. Various geotechnical (physical, mechanical and chemical) tests were conducted based on standard specifications.      The results of the grain size test of clay samples showed their conformity with Zone C curves and their suitability for the construction of embankment dams, according to the Iraqi standard for roads and bridges.  The results of the plasticity limits test showed that the soil is made of fine, low plasticity silt (ML), and low plasticity clay (CL), according to the unified standard soil classification. The water content and plasticity limit tests (liquid limit, plastic limit, and plasticity index) demonstrated that these clays are conformable with the limits of the Iraqi standards. The results of the modified compaction test found a maximum dry density value of 1.962 g/cm3 with an optimum moisture content of 11.5%. The results of the permeability index (K) revealed low permeability according to the Das classification and, therefore, showed the suitability of the samples as raw filling materials in the construction of dams. Chemical tests (sulfate content, organic materials content, total dissolved salts, gypsum content, and pH value) showed compatibility with the requirements for the use in dams construction under the Iraqi standard (SoRB/ R5).


2013 ◽  
Vol 710 ◽  
pp. 348-351
Author(s):  
Zheng Rong Zhao ◽  
Lei Wang ◽  
Hong Xia Yang

Through compaction test discussed about the compaction characteristics of expansive soil by lime modified in middle of Shandong province. The results show that the optimum moisture content is lower when the expansive soil is cured by dry compaction method, and the maximum dry density is higher. Compaction curve appeared the phenomenon of two peaks when expansive soil is cured by wet compaction method.Lime content of lime improved expansive soil, particle size composition, age and compaction function have influence on compaction curve.With the increase of the quantity of lime, the optimum moisture content increases, the maximum dry density decreases. With the age growth, the optimum moisture content increase slightly,the maximum dry density decreases slightly. The bigger the compaction work, the smaller moisture content is, the larger the maximum dry density is.


2018 ◽  
Vol 250 ◽  
pp. 01008
Author(s):  
Tuan Noor Hasanah Tuan Ismail ◽  
Siti Aimi Nadia Mohd Yusoff ◽  
Ismail Bakar ◽  
Devapriya Chitral Wijeyesekera ◽  
Adnan Zainorabidin ◽  
...  

Soils at many sites do not always have enough strength to bear the structures constructed over them and some of the soil may need to be stabilized in order to improve their geotechnical properties. In this paper, routine laboratory tests were critically carried out to investigate the efficacy of lignin in improving the strength behaviour of the soils. Two different soil samples (laterite and kaolin) were studied and mixed with different proportions of lignin (2% and 5% of dry weight of soil), respectively. Unconfined Compressive Strength (UCS) characteristics evaluated in this study were done on samples at their maximum dry density and optimum moisture content (obtained from compaction tests). The UCS tests on all the specimens were carried out after 0, 7, 15, 21 and 30 days of controlled curing. The research results showed that the addition of lignin into kaolin reduced its maximum dry density while giving progressively higher optimum moisture content. Contrarily, with the laterite soil, both maximum dry density and optimum moisture content simultaneously increased when lignin was added into the soils. The UCS results showed that the the stabilized laterite with 2% lignin continued to gain strength significantly at a fairly steady rate after 7 days. Unfortunately, lignin did not show a significant effect in kaolin.


2014 ◽  
Vol 20 (2) ◽  
pp. 169-174 ◽  
Author(s):  
Vahid Ayan ◽  
Mukesh C. Limbachiya ◽  
Joshua R. Omer ◽  
Seyyed Masoud Nasr Azadani

Study was recently conducted at Kingston University to assess the suitability of using recycled concrete aggregate (RCA) and reclaimed asphalt pavement (RAP) in unbound subbase mixtures. The results showed that the use of 100% recycled aggregates increased the optimum moisture content and decreased the maximum dry density of the sub-base materials in comparison with natural aggregates. Moreover, the replacement of RCA by reclaimed asphalt pavement by 50% decreased the optimum moisture content and increased the maximum dry density in proportion to 100% RCA. The effects of physical properties on 0% air void and compaction curve were discussed for each type of subbase. The CBR values of the subbase materials prepared with 100%RCA is lower than subbase mixture with 100% natural aggregates. The CBR further decreased for replaced subbase with RAP so that 50%RCA + 50%RAP is not suitable for unbound subbase from the point of CBR view. In each mix the trend of CBR value was investigated in terms of water content. This research found some significant practical points to use in site works.


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