CBR Value Research Articles

Stabilization of expansive soil with terrasil and coir fiber as a subgrade for pavement

This research is intended to enhance the strength and permeability properties of black cotton soil or expansive soil of high plastic clay (CH) by combining soil with coir fibre and Terrasil additives. The distributions of the additive’s coir fibre and Terrasil used in the analysis are expressed as a percentage of the soil’s dry weight. The Terrasil and coir fibre proportions used in this study are 0.5% Terrasil and 0.5%,1.0%,1.5%, and 2.0% coir fibre, respectively. According to the analysis or test results, clay subgrade soil stabilized with 0.5% Terrasil and 1.5% coir fibre exhibits specific values for strength and CBR value improvement. The UCS confidence interval for the combined application of soil+0.5%Terrasil+1.5%coir fibre increases from 26.566 kpa to 27.209 kpa in the untreated soil. The CBR computed value for the treated soil is 90% usually higher than the untreated soil, lowering the layers demanded for the subgrade. Permeability values of 1.5% and 2.0% for coir fibre and 0.5% for Terrasil outperformed that of untreated soil. After the additives are incorporated into the soil, the mineralogy of the soil and the Bonding mechanism phenomena are inspected (or) investigated using XRD, SEM, and FTIR.

Impact of rice husk ash and xanthan gum in road works by improving the characteristics of expansive soil (black cotton soil)– an inclusive study

The soils of Indian Black Cotton are well-known examples of Expansive soils, which display significant swelling and shrinkage in response to changes in moisture content. The distressing cyclical swelling and shrinking of soils under moisture fluctuations lead to serious failures. Stabilization of soil can be used to improve it in order to get around this. An agricultural industrial waste called rice husk ash is created when rice husk, a byproduct of paddy milling, is burned. In delta regions, it is widely distributed. It is a pozzolanic material that is widely distributed in India and has potential use in a number of geotechnical areas. In this stabilisation process, black cotton soil is mixed with RHA-lime and various percentages of cementitious material, particularly lime. Tests such as plasticity, compaction, swell, and CBR were also conducted with different water contents of OMCs (such as OMC + 2% water content and OMC + 5% water content). From the test findings, it can be concluded that adding lime reduces flexibility and increases strength. With the addition of RHA and lime, expansive soil gets higher CBR values at varied water contents more than 50% for dosages of 10% lime + 20% RHA and 10% lime + 30% RHA. The expansive soil becomes non-plastic, non-swelling, and has increased strengths, making it suitable for use as a building material for roads.

Experimental study on black cotton soil treated with xanthan gum and palm oil fuel ash

This paper presents the results of the laboratory evaluation of black cotton soil stabilized with Palm Oil Fuel Ash(POFA) and Xanthan Gum(XG), to determine its suitability as reliable construction material. POFA, a major byproduct of the palm oil industry is being dumped into open fields which can cause environmental problems. Using POFA as an additive in soil stabilization can be an eco-friendly and sustainable practice. XG which is generally used as a thickening agent in the food and pharmaceutical industries is used in this study as a binding material. Several influential properties such as UCS, CBR, Compaction characteristics, and Atterberg limits were found for control samples and compared with the samples treated with different percentages of POFA and XG ratio and on different curing periods. The tests are performed by varying the POFA (0-25%) while keeping the XG constant at 1% to the weight of dry soil. The specimens were cured for different curing periods. There is a significant change in the shear strength of the soil as the UCS value increased by 374% and the CBR value increased by 379% when the control sample is compared with those of treated samples with 20% POFA+1% XG at 90-day curing period.

Stabilization of alluvial soil with fly ash and GGBS as a subgrade for pavement construction

With the significant increase of construction activities in the road sector, the scenario has awakened the need for typical good quality soils for subgrade construction which are deficient in supply at many locations for numerous reasons. In this research activity, comprehensive study in the laboratory has been carried out to examine the use of fly ash and GGBS (Ground Granulated Blast Furnace Slag) to stabilize alluvial soils. Multiple influential properties such as UCS, CBR, Permeability, swelling potential, Compaction characteristics, and Atterberg limits were found for control samples and compared with the samples of distinct sequences of different percentages of Fly ash and GGBS ratio and on different curing periods. All the tests are performed by varying the Fly ash content to 5%,15%,25%,35% and 45% while keeping the GGBS content constant at 5% to the weight of dry soil. There is a remarkable change in the shear strength of the soil as the UCS value increased by 150% and the CBR value increased by 389% when the control sample is compared with those of treated samples with 35% Flyash+5% GGBS

Improvement in Soil Sub Grade Using Rice Husk Ash and Silica Fume by Soil Stabilization.

Abstract: Black cotton soil shows high swelling and shrinkage and less CBR value and strength due to presence of Montmorillonite mineral. Black cotton soil cannot be use for structural purpose in construction industry due to its expensive nature, therefore to control expensive behavior of the soil rise husk ash and silica fume is used in this experimental study. Rise husk ash used 0-15% by weight for observe experiment results and silica fume 0-12% by weight for observation of experiment results. Plasticity index, Free swell index of soil is decreasing with respect to RHA and SF addition and CBR value and shear strength of soil is increasing with respect to addition of RHA and SF . Optimum percentage of rise husk ash (RHA) and Silica fume (SF) observed as 12% and 9% respectively.

Geotechnical Characteristics of Fine-Grained Soils Stabilized with Fly Ash, a Review

Fly ash is a waste material obtained from burning of coal in thermal power plants. Coal consumption is still very high and is expected to remain above 38% globally. Therefore, large volumes of fly ash are produced every year that need to be managed as waste. Improper disposal of fly ash can lead to surface water and ground water pollution and adversely affect human health and environment. The use of fly ash as an agent to stabilize soil has recently become popular in geotechnical engineering due to its many benefits such as being eco-friendly and cost-effective, and improving the geotechnical characteristics of the soil. This paper presents a review of the geotechnical properties of fly ash-stabilized fine-grained soils. Several features of fly ash, including classification, physical, geotechnical, chemical, and mineralogical properties, health concerns, disposal, availability, and cost are analyzed. The effects of fly ash in improving a wide range of mechanical properties of soils including unconfined compressive strength, shear strength, CBR value, consolidation and/or swelling characteristics, and permeability are reviewed in detail. It is shown that fly ash can be a substitute material for use in soil stabilization, leading to substantial economic and environmental benefits.

Aggregation and dehydration of excavated soft clay and use for subgrade engineering-part 2: A pilot-scale study

This paper presented a pilot-scale investigation into the performance of stabilized-soil aggregates for subgrade, which was generated from dehydration and aggregation of excavated soft clay. The evaluation work consisted of three parts. Firstly, an industrialized production line, aiming to produce aggregates efficiently was established. The produced aggregates were then employed to construct a trial embankment. Finally, a series of in-situ tests were performed on the product and embankment to evaluate the suitability of the manufactured product for subgrade engineering. It was found that the technique proposed in the companion paper was also feasible on an industrial scale, and the dehydration rate was around 68 % of the laboratory scale, which was considerably higher than natural drying. Although the dehydration rate was decreased by a certain amount, enlarging the production scale from precisely controlled laboratory scale to field pilot scale had little effect on the engineering properties of products. After dehydration and aggregation, the high plasticity clayey soil was transformed into low plasticity silty soil, showing excellent soaked CBR values (over 30 %). When used within the embankment, the constructed embankment exhibited reliable stiffness (e.g., DCPI ≤ 4.2 mm/blow and Mr ＞ 70 MPa) and premium water stability, which could well satisfy the requirement of extremely heavy traffic load stated in the standards. The influences of such modification of soil characteristics on estimation of in-situ CBR values and selection of compaction methods were also discussed. Based on the discussion, some recommendations for proper use of the stabilized-soil aggregates on subgrade engineering at an industrial scale were given.

CBR laboratory investigation on Lightweight Modular Block (LMB) using recycled dredged soil mixed with EPS

Changing material into a lightweight geomaterial such as EPSCS is one of the considerable methods to improve the geotechnical performance in the field. This material is already used in numerous construction projects due to its light characteristics. Lightweight Modular Block or LMB is a type of EPSCS composed of dredged Soil, cement, and Expanded Polystyrene (EPS). The amount of cement composition are 3%, 5%,7% and 9%. Meanwhile, Expanded Polystyrene (EPS) are 0.5% and 0.75%. This paper aims to briefly explain the performance of LMB as road foundation materials, such as subbase and base, through CBR laboratory tests. Based on the data, adding EPS can reduce density by 18% - 29% depending on the chosen mixture. Whereas adding more cement tends to increase the CBR value. All the test results will be analyzed and compared to SNI 03-3438-1994 for its qualification as a road foundation layer.

Stabilization of Dredged Materials Using Cement and a Pozzolanic Binder Mineral Additive

In this study, it was aimed to stabilize the dredged materials with low bearing capacity, brought from Edirne, by using cement and pozzolanic binder mineral additives. In the first stage of the study, the geotechnical properties of the dredging materials were determined. Then, the optimum water contents and maximum dry unit weight values of the soil samples without additives and with different additive ratios were found by compaction tests. Pure and additive unconfined compressive samples were prepared with the optimum water contents obtained in the compaction tests. Samples were prepared by adding 8%, 10% and 12% cement and 2% pozzolanic binder additive by weight to the dredged materials. Unconfined compressive tests were performed on the samples at the end of instant, 1-day, 7-day and 28-day curing periods. In addition, soaked CBR, permeability and flexural tests were performed on 12% cement+pozzolanic added samples. As a result of the experiments, with the addition of cement and pozzolanic binder additives in different ratio to the dredged materials, permeability decreased, unconfined compressive strength, soaked CBR values and flexural strength increased significantly.

Improving the Characteristics of Subgrade Soil Using Different Chemical Additives: Case Study Al-Nasiriya Soil

The roads in the city of Nasiriya in southern Iraq suffer from problems that occur as a result of repeated vehicle loads or due to weak soil and lead to losing their performance and being out of service despite their construction for a very short period. The use of chemical additives to improve the subgrade widely worldwide and give strength and durability to the weak soil while the possibility of using chemical additives for the substrate in Al-Nasiriya is still practically limited. The study aimed to verify the use of chemical additives (cement, lime, and ferric chloride) and to know their effect on the properties of Al-Nasiriya soil. The results showed a clear improvement in the UCS test when using chemical additives, and then the optimal percentages of additives were determined and were 9%, 10%, and 2% respectively, in addition to knowing the effect of the curing period (1, 7 and 14) days on the results of the test. For the other tests (maximum dry density, CBR, swelling, and optimum moisture content) were verified for the optimal chemical percentages and it was observed that the CBR values increased and the swelling values decreased after treatment and soaking in water for all additives, while the compaction parameters had a different behavior between the materials additive used.

Reduction of pavement thickness using a subgrade layer treated by different techniques

A range of stabilisers for poor quality subgrade soils have been developed to promote road constructions. Many of them are becoming more popular depending on their effectiveness. The purpose behind this research is to identify the relative efficacy of many physical and chemical stabilisation techniques for enhancing the properties of three types of local Iraqi subgrade soils. The comparison of the samples is based on the CBR tests. The AASHTO (1993) flexible pavement design was used to compute the pavement thickness requirements. The soil samples A, B and C have a natural CBR values of 3.8, 3.9 and 4, respectively, on which the physical stabilisers of Powdered rock (PR), grained recycled concrete (GRC), and recycled crumb rubber grains (CR) were employed, while Quicklime (QL) and activated fly ash (AFA) were both utilised as chemical stabilisers. The stabilisation with 15 % of AFA proved to be the most applicable method for soil types A and B for reducing the pavement thickness requirements by 51 % and 32 %, respectively, with a reasonable financial feasibility for both. The same feasibility is proven when stabilising soil type C with 15 % of GRC, which reduces the pavementthickness by 25.7 %.

Performance Testing Of Sand And Lime As Subgrade Stabilizing Materials For Roads

Soil stabilization is a method used to increase the carrying capacity of a layer of soil, by giving special treatment to that layer of soil. Soil is one of the factors that can affect the structure of road construction. The CBR value is one of the parameters to determine soil carrying capacity, if the CBR value is high then the soil carrying capacity is good, whereas if the CBR value is low then the soil needs to be stabilized. The purpose of this study was to determine the characteristics and classification of soil, determine the results of the grain gradation test, sieve analysis and hydrometer analysis, consistency limits (Atterberg limits) before and after stabilization, compaction results (Proctor) before and after stabilization, determine the CBR value of the soil before and after stabilization. This research included water content test, wet soil unit weight test, specific gravity test, sieving analysis, hydrometer analysis, Atterberg limit test, compaction test (Modification), and immersion CBR test and CBR without immersion. In this test, variations in the addition of 20% sand and lime content were 5%, 10% and 15% of the dry weight of the soil. From the test results, the original soil samples showed soil classification A-7-6 according to AASHTO with maximum dry density (MDD) values of 1.70 gr/cm3 1 day curing, 1.64 gr/cm3 7 days curing and 1.77 gr/cm3 for 14 days curing, there was an increase in the value of the maximum dry density (MDD) in the original soil stabilized with 20% sand and 5% lime, a value of 1.78 gr/cm3 was obtained for 1 day curing, 1.86 gr/cm3 cm3 7 days curing and 1.82 gr/cm3 14 days curing. From the test results, the original soil samples showed soil classification A-7-6 according to AASHTO with CBR values of soaked 3.15% 1 day curing, 3.68% 7 days curing and 4.21% 14 days curing, there was an increase Soaked CBR values on native soil stabilized with 20% sand and 5% lime obtained CBR values of 37.19% at 1 day curing, 42.10% 7 days curing and 30.29% 14 days curing.

A Study of Cost Comparison of Flexible Pavement Using Different Soils

India is home to the world’s second-largest road network. It has a diverse range of soil types, each with its own set of conditions and characteristics, on which the road network is built. IRC: 37-2018 was used for the Design and Cost Analysis of Flexible Pavement for five distinct types of soils: Black cotton soil, Alluvial soil, Sandy soil, Red Laterite soil, and Murram soil. The Resilient modulus which depends on CBR value of the soil has been found to influence the pavement thickness, strength and performance. The project’s cost is determined by the pavement thickness, which again is determined by the soil’s CBR value. By employing a soil with a high CBR value, the project’s pavement thickness and cost will be decreased. On poor or problematic soils, soil stabilisation techniques should be employed to improve CBR value and save project expenses. According to the findings, employing the CBR value improves the pavement’s strength and hence saves time when planning a pavement.

Peningkatan Parameter Mekanis Tanah Lempung Plastisitas Tinggi sebagai Bahan Timbunan dengan Penambahan Kapur

The clay plasticity can be reduced chemically using lime which contains Ca++ and Mg++ to neutralize the swelling and shrinkage properties. The test soil sample from Teluk Mesjid Village, Balangan Regency, has a 51% liquid limit, a 30.45% plastic limit and 20.55 Plastic Index, it is not specified as an embankment material. The lime percentage was based on plasticity test on soil mixed with 4%, 6% and 8% lime. Direct shear and independent compressive strength tests were carried out on the original soil samples and soil samples with addition of 6% lime resulting from standard and modified compaction as well as CBR tests for unsoaked and soaked conditions. The lime addition reduced the Plasticity Index greatly from 20.55% to 5.84% or to low plasticity category. Soil cohesion increased up to 100%. The shear angle increased was only 2-3°. The ultimate bearing capacity of the free compression test from modified compaction increased significantly up to 100%. The increase in CBR value in soaked conditions reached 59.6% to 63%. The soaked CBR value with lime addition increased from 7% to 17.4% or increased for 2.48 times.

IMPACT OF GEOTEXTILE ON THICKNESS OF ROAD LAYERS

There is considerable promise for geotextiles, a new field in civil engineering and other fields, with a wide range of applications around the world. Modern pavement design and maintenance rely heavily on the use of geotextiles. The exponential rise in its use, particularly in transportation, around the globe has been nothing short of astounding. Using geotextiles as a building material for infrastructure projects such as roads, harbors, and many others is a great concept. In the future, they will have a bright future because of their multifunctionality. This study focuses on the use of geotextiles in the construction of pavements and the use of Recycled Concrete Aggregate (RCA) to construct new roads which will drastically reduce the strain on our natural resources and this also will provide us an effective way of managing the waste produced by demolition of old structures. RCAs are not easy to work with and do not produce the results as good as natural aggregates because of presence of old adhered mortar around it hence geotextiles are used to enhance their performance and improve the overall CBR value of road

Stabilization of expansive black cotton soil using bioenzymes produced by ureolytic bacteria

Soil stabilization is the art and science of improving the engineering properties of soils. The properties of problematic soils can be improved by blending appropriate amount of insitu soil, aggregates and bioenzymes. In the present study, four bacterial strains: Sporosarcina pasteurii, Bacillus paramycoides, Citrobacter sedlakii, and Enterobacter bugadensis were used to produce bioenzymes using urea supplemented molasses as a substrate via submerged fermentation. The crude bioenzyme was mixed with modified soil blended with 40% black cotton soil, 30% aggregate and 30% river sand; then tested after curing for 7 days. The test results revealed that except soil samples treated with bioenzyme of Enterobacter bugadensis, all treated soil samples showed improved plasticity index (18–55%) and liquid limit (5–44%). Soil samples treated with bioenzyme of Bacillus paramycoides, Citrobacter sedlakii and Sporosarcina pasteurii showed higher CBR values of 12.9%, 12.27%, and 11.95% respectively. On the other hand, free swell showed reduction in soil samples treated with bioenzymes of Sporosarcina pasteurii (47.37%), Bacillus paramycoides (30%), and Citrobacter sedlakii (10.53%). The highest percentage improvement of linear shrinkage was recorded for soil sample treated with bioenzymes of Sporosarcina pasteuri (39.65%), followed by Permazyme (10.44%), Citrobacter sedlakii (8.4%) and Bacillus paramycoides (8.34%). Whereas, the highest percentage improvement in MDD was recorded in permazyme treated soil (11.92%) followed by molasses (8.29%), Bacillus paramycoides (1.92%), and Enterobacter bugadensis (0.73%). The lowest optimum moisture content (9.3%) was recorded in soil treated with permazyme. Triaxial test analysis also showed improvement in both cohesion and angle of friction in bioenzyme treated soils. From the test results it was concluded that it is possible to treat expansive black cotton soils using bioenzymes produced from low cost substrates such as molasses and reduce the cost of construction and environmental carbon emission.

ANALISIS DAYA DUKUNG TANAH DASAR BERDASARKAN UJI CBR LABORATORIUM DAN UJI CBR LAPANGAN PADA RUAS JALAN KAMPUS UNIPAS MOROTAI

The development of land transportation, in this case the highway in Morotai Island Regency, is currently very fast. One of the roads planned for the construction of a new road is the Unipas Morotai Campus Road Section. So far, the construction of new roads in Morotai Island Regency has not been optimally carried out by a survey to test the condition of the subgrade and the strength of the base soil. The purpose of this study was to determine the carrying capacity of the subgrade for the purpose of planning pavement thickness on the Unipas Morotai campus road through direct field testing with laboratory testing. The results showed that the soil types in the 3 sampling locations were loamy soils with high water content in the field between 30-35%. The laboratory CBR value at point 01 is 33%, point 2 is 28% and point 3 is 49%. These results indicate that from the results of laboratory testing, subgrade fulfills the requirements as a subgrade on road pavement where CBR> 5%. The CBR value of the field tested at point 6 test points gave a varied value of 4.64% -6.96%. These results indicate that from the lab test results, subgrade fulfills the requirements as a subgrade on the pavement where CBR> 5% at point 01 , and point 04. Meanwhile, the other 4 points did not meet their CBR values so that special compaction was needed in the field..

APPLYING BIOGEOGRAPHY-BASED MULTI-LAYER PERCEPTRON NEURAL NETWORK TO PREDICT CALIFORNIA BEARING CAPACITY VALUE OF STABILIZED POND ASH WITH LIME AND LIME SLUDGE

In this study, a hybrid biogeography-based multi-layer perceptron neural network (BBO-MLP) with different number of hidden layers (one up to three) was developed for predicting the California bearing capacity (CBR) value of pond ash stabilized with lime and lime sludge. To this aim, model had five variables named maximum dry density, optimum moisture content, lime percentage, lime sludge percentage and curing period as inputs, and CBR as output variable. Regarding BBO-MLP models, BBO-MLP1 has the best results, which its R2 stood at 0.9977, RMSE at 0.7397, MAE at 0.476, and PI at 0.0104. In all three developed models, the estimated CBR values specify acceptable agreement with experimental results, which represents the workability of proposed models for predicting the CBR values with high accuracy. Comparison of three developed models supply that BBO-MLP1 outperform others. Therefore, BBO-MLP1 could be recognized as proposed model.

EXPANSIVE SOIL STABILIZATION USING IRON ORE TAILINGS

The foundation of the natural world is the soil, which is prevalent in many parts of India and has a high silt content, low strength, and weak bearing ability. The loads placed on these soils during construction or during the structures useful life are too great for them to bear. In India, expansive soil covers 20 percent of the land. To enhance the functionality of expansive soils, soil stabilization is used.In this research work, an attempt has been made to use Iron Ore Tailings (IOT) an industrial by-product as stabilizing agent for expansive soil. In this study, expansive soil is replaced with IOT from 0% to 30% at 5% interval. It was found from the experimental observations that the values of Liquid limit and Plastic limit decreased with increase in percentage of IOT. Free swell index shows a total decrement of 55% at 30% IOT content. MDD of standard and modified compaction increased with higher percentage of IOT whereas the OMC decreased accordingly. CBR values of un-soaked condition yielded whereas no penetration resistance was observed in soaked condition. Swelling pressure effectively decreased to a total of 50% at 30% IOT content. Hence, it can be concluded that IOT will help in improving the mechanical properties of expansive soil.

VALORIZATION OF MATERIALS FROM ROAD WASTES: CASE OF THE SEASHELL AGGREGATE

The main objective of this study is to see to what extent it is possible to recover a material from road waste: the case of the seashell aggregate. Public works produce 100 millions tonnes of surplus and construction waste every year. Among the 100 million tons, 95% is inert and non-polluting waste. And faced with the ever-increasing demand for road construction materials and the scarcity of materials satisfying the specifications, it is urgent to initiate study programs on the possibility of using the materials in place in order to anticipating the total exhaustion of careers. In road works, and in particular for making embankments and capping layers, the bearing capacity of the soil, i.e. its resistance to rupture, is determined by the test C.B.R. (Californian Bearing Ratio) or Californian lift test. Thus, after characterization, the seashell aggregate from road waste was improved with Portland cement with different percentages. We find with a treatment at 1.5% then 2.5% respective CBR values ​​of 94 and 140. This work shows that these materials can be reused in road construction.