Optimum Moisture Content Values Research Articles

Effects of the application of anaerobically digested sewage sludge on the consistency limits and compaction characteristics of differently textured soils

Notwithstanding their beneficial characteristics, the agricultural utilization of organic wastes may have an adverse effect on soil properties if used improperly. To evaluate proper use, a laboratory study was conducted to investigate the effects of different sewage sludge application doses (0, 2, 4, and 8% weight/weight) on the consistency limits and the compaction characteristics of three differently textured soils. The application of sewage sludge significantly improved the consistency limits and reduced the compactibility. The efficacy depended on the amount applied. The rates of increase in liquid limit (LL) values at 8% sewage sludge were 58.7% for sandy loam, 43.4% for loam, and 16.2% for clay soil. As the application dose increased, the optimum moisture content (OMC) values increased and the maximum dry bulk density (MBD) values decreased. The highest application dose decreased the MBD by 9.5% in sandy loam, by 6.5% in loam, and by 13.7% in clay-textured soils. The rates of increase in OMC values were 73.4%, 53.8%, and 27.1%, for sandy loam, loam, and clay, respectively. The results presented in this study clearly indicated that the application of sewage sludge made the soils more resistant to mechanical forces, since the increase in the proportion of OMC over LL and PL implied that the soil was easier to till at higher moisture contents without any deformation, which also resulted in a higher workable range.

Enhancing the Compaction Characteristics of Peat Soil through Ground Granulated Blast Furnace Slag (GGBS) Stabilisation

Peat soil is renowned for its compressibility problem that can give rise to issues such as ground settlement, particularly within the spectrum of construction endeavours. Conversely, the implementation of chemical stabilisation, involving the incorporation of suitable additives, is contemplated prior to commencing construction activities. Ground Granulated Blast Furnace Slag (GGBS), which is a byproduct of the iron and steel industry, stands out as a prominent additive that can augment the engineering attributes of peat soil. This investigation focuses on the compaction characteristics of peat soil treated with varying proportions of GGBS, as evaluated through the Modified Proctor test. It involved examining the impact of diverse GGBS additions on the liquid limit of peat soil. The findings showed that the introduction of GGBS yielded a substantial reduction in the liquid limit of peat soil, signifying an elevated susceptibility to moisture and an increase in plasticity. Moreover, the incorporation of GGBS into peat soil prompted an increase in its Maximum Dry Density (MDD) and a reduction in its Optimum Moisture Content (OMC). Notably, the peak MDD, registering at 1000 kg/m³, was achieved at a GGBS content of 50%, marking the highest value observed in this study. The OMC values further indicated the lowest moisture content, standing at 29%, with the addition of 25% GGBS to the peat soil. These outcomes convincingly advocate that the utilisation of GGBS in treating peat soil engenders positive enhancement in its compaction characteristics, specifically pertaining to MDD and OMC. Such enhancement in engineering properties holds promising implications for potential stability.

Wood ash as a stabilizer for pavement subgrade

Soil stabilization techniques have been widely accepted as a measure for enhancing the soil engineering properties. Use of conventional additives such as lime, cement, etc. has been found to have long-term environmental and economic limitations. In this study, wood ash has been experimented as a subgrade stabilizer for sodium bentonite clay, which is a weak pavement subgrade. Chemical composition and index properties of wood ash and bentonite were determined. Bentonite was replaced with 0%, 10%, 20%, 30%, and 40% of wood ash to determine the changes in the engineering properties. Experimental results showed that the maximum values of Optimum Moisture Content (OMC), Maximum Dry Density (MDD), and Unconfined Compressive (UCC) Strength, lie between 20% and 30% dosages of wood ash. Further experiments were conducted with 22%, 24%, 26% and 28% dosages of wood ash in bentonite, which showed optimum strength properties at 24% mix percentage. UCC strength at optimum wood ash dosage at 0 days and 7 days of curing were 122 kPa and 148 kPa respectively. CBR value for soaked specimen at optimum dosage was found as 7.3%. Substantial results prove that wood ash is a successful stabilizer for sodium bentonite as pavement subgrade. This also provides a sustainable solution for disposal of wood ash.

Experimental investigation on soil stabilization technique by adding nano-aluminium oxide additive in clay soil

In this research article, soil stabilisation is carried out by the latest method: nanotechnology. The stabilizer nano-aluminum oxide is used as a stabilising agent in concentrations of 0.2%, 0.4%, 0.6%, 0.8%, 1%, and 1.2%. Because it is 99% pure and nanoscale, it has a large surface area for analysing the properties and strength of soil tests such as Atterberg's limit, pycnometer, proctor compaction test, California bearing ratio test, and unconfined compressive strength. These tests are done for parent soil and soil with different percentages of nanomaterials. The nanostabilizer addition increases the unconfined compressive strength, California bearing ratio, liquid limit, and optimum moisture content value. One percentage of nano-aluminium oxide is considered an optimum dosage. Beyond the optimum amount, there is a change in soil property. The CBR value, liquid limit, and OMC of soil all go down, so it is recommended to use 1% nano-aluminum oxide to improve sub-grade clay soil.

Study of the geotechnical behavior of soil-cement reinforced with plastic bottle fibers

This study aimed to evaluate the influence of adding plastic bottle fibers to soil-cement mixtures and the possible improvements generated by the addition of a blend of two types of additives, namely, additive 1 (waterproofing improver) and additive 2 (adhesion enhancer), in the compactability and shear strength parameters of soil-cement-plastic fiber mixtures, considering a tropical residual soil. The fibers used in this study are made of Polyethylene Terephthalate (PET), produced from soft drink bottles, and added to the soil with 2 mm width and 1 cm length, in the content of 1% in relation to soil dry mass. Also, contents of 3% and 5% Portland cement, in relation to soil dry mass and two additives, additive 1 at a ratio of 0.25 kg m-³ dry soil and additive 2 at a ratio of 0.60 kg m-³ dry soil, were used to evaluate the possible effect of these variables on the investigated engineering behavior parameters. The compaction results indicated that the inclusion of PET fibers in soil-cement mixtures tends to decrease the maximum dry unit weight compared to fiber-free mixtures. Also, if compared to soil-cement-fiber mixtures, the incorporation of additives to soil-cement-fiber composites resulted in higher values of maximum dry unit weight and lower values of optimum moisture content, but still maintaining values lower than obtained for compacted soil. Results of the direct shear test showed enhanced shear strength with the addition of fibers to soil-cement, for both the parameter of cohesion and the internal friction angle of the material in comparison to fiber-free composites, which demonstrates the potential application of these composites in geotechnical works.

Engineering Assessment of the Soils of Modern Residential Complexes (Bety, Yarmouk, and Al-Jawhara) in Tikrit/Salah Al-din/Iraq

In this research, the geotechnical properties of soil for modern residential complexes in the city of Tikrit-Iraq were determined using six samples represented by three residential complexes (Bety, Yarmouk and Jawhara) and that these complexes built on gypsum soils suffer in the future from several engineering problems that appear in the form of cracks, inclination or subsidence in The buildings or the collapse of the facilities, the dilution of the roads and the breaking of the water and sewage networks due to the melting of the gypsum in the soil. One of the most important objectives for the research is that the residential complexes for the research area in Tikrit are not older than some years. With the urban expansion that all towns in Iraq are witnessing, including this region, the city of Tikrit represents the center of the province. Therefore most of the departments and institutions are present in this region, which necessitated the need to provide residential complexes and many of the constituencies' employees to occupy them in addition to its proximity to the University of Tikrit, so it is necessary to know the properties of soil, to point out the engineering problems in it and how to address them. As well, it is an important region from a geographical point of view because it is located directly on the main international road linking Baghdad - Tikrit – Mosul The moisture content values of the soil samples range from (0.92 to 0.26%). The resultant values ​​are low because one of the reasons is that the sampling process took place in the summer, specifically in July, and the reason is due to the low level of groundwater in the region, as well as the high temperature and the lack of rainfall, which causes the evaporation of the water in the soil, so the low moisture content gives a positive concerning the foundations of residential complexes in the study area because the presence of water causes the dissolution of gypsum as the soil under study contains a high percentage of gypsum. The calculated specific gravity values of soil samples range from 2.42 to 2.46 with an average of 2.42, The average specific gravity is 2.42 in the Bety and Yarmouk, and it is 2.46 in Aljawhara. The maximum dry density values of the soils of the residential complexes range between (1.611-1.663 gm/Cm 3( and the highest dry bulk density value was recorded in the sample (Y1). On the other hand, the optimum moisture content values range between 15.2% and 16.8%, while the highest value is for the sample )B2(. The consolidation test was performed on three selected samples (B2, J1, J2), ((A correction was made for the selection of samples to consolidation test based on the clay ratio, as was the case with the sieving analysis)) based on their clay content percentage compared to other samples which contain low or very clays, The compression index values (Cc) and the bulge index values (Cr) of these samples ​​are (0.084,0.114,0.092) and (0.012,0.013,0.009) respectively. The chemical analyses of the soil in the study area indicates that it contains a high percentage of gypsum that ranges between 43.05 and 69.27. % The gypsum content reaches the highest value in sample (B2) and lowest in sample J2. While the soluble salts percentage range from 73.13)to 85.21%), and the pH value ranges between 7.21and 7.67. Mineralogical, tests of indicate that most samples have prismatic gypsum crystals with several clinker substances, carbonate and evaporites cement and organic materials. The gypsum crystals range in size from 0.02 to 0.7mm with an amount of clay.

A Comparative Study on Soil Stabilization Relevant to Transport Infrastructure using Bagasse Ash and Stone Dust and Cost Effectiveness

Soft ground improvement to provide stable foundations for infrastructure is national priority for most countries. Weak soil may initiate instability to foundations reducing their lifespan, which necessitates the adoption of a suitable soil stabilization method. Amongst various soil stabilization techniques, using appropriate admixtures is quite popular. The present study aims to investigate the suitability of bagasse ash and stone dust as the admixtures for stabilizing soft clay, in terms of compaction and penetration characteristics. The studies were conducted by means of a series of laboratory experimentations with standard Proctor compaction and CBR tests. From the test results it was observed that adding bagasse ash and stone dust significantly upgraded the compaction and penetration properties, specifically the values of optimum moisture content, maximum dry density and CBR. Comparison of test results with available data on similar experiments conducted by other researchers were also performed. Lastly, a study on the cost effectiveness for transport embankment construction with the treated soils, based on local site conditions in the study area of Assam, India, was carried out. The results are analyzed and interpreted, and the relevant conclusions are drawn therefrom. The limitations and recommendations for future research are also included. Doi: 10.28991/cej-2021-03091771 Full Text: PDF

Physical, Chemical and Geotechnical Characterization of Wet Flue Gas Desulfurization Gypsum and Its Potential Application as Building Materials

In South Africa, coal represents the primary source of energy used for electricity generation. Coal power plants use the wet flue gas desulfurization (WFGD) process to remove sulfur dioxide (SO2) from their flue gas. However, this technology produces a large amount of synthetic gypsum, resulting in waste disposal and environmental pollution. This study investigated the physical, chemical and geotechnical properties of WFGD gypsum and its potential application to develop cement-free bricks. WFGD gypsum was collected from a coal power plant in South Africa. It was found that the principal oxides of WFGD gypsum were sulfur trioxide (SO3) and calcium oxide (CaO), which represented more than 90% of the total weight. Calcium sulfate (CaSO4) and calcium di aluminate (CA2) were the predominant minerals in the raw material. The density of the WFGD gypsum was 2.43 g/cm3. The maximum dry density and optimum moisture content values were 1425 kg/m3 and 18.5%, respectively. WFGD gypsum had a liquid limit of 51% but did not display any plasticity characteristics. The optimum curing temperature of gypsum bricks was 40 °C. WFGD gypsum-based bricks exhibited compressive strength of up to 2.3 MPa and a density of about 28% less than that of typical clay bricks. Additionally, there was no significant decrease in compressive strength after seven wet/dry cycles. These results show that WFGD gypsum could be used to produce lightweight building materials with low strength requirements.

Strength performance and microstructural evolution of carbonated steel slag stabilized soils in the laboratory scale

The technique of carbonated stabilization is an innovative method to improve the engineering performance of soft soils. However, the improvement in the engineering performance of stabilized soils with carbonized steel slag has not been studied. In addition, the effect of clay minerals on carbonation parameters and D-W cycle performance remains unknown. To this end, in this paper, three types of synthetic soils containing different clay minerals were prepared to be stabilized by carbonated steel slag. The strength performance and microstructural evolution of carbonated steel slag stabilized soils were investigated by drying-wetting (D-W) cycle tests, unconfined compression strength (UCS) tests, X-ray diffraction (XRD), thermogravimetry (TG), and scanning electron microscopy (SEM). The results showed that the compressive strength after and resistance to D-W cycles of carbonated steel slag stabilized soils were significantly improved due to carbonation treatment. The presence of clay minerals in stabilized soils led to the high values of optimum moisture content for carbonation (C-OMC). The C-OMC value of stabilized soils containing montmorillonite was higher than that of stabilized soils containing kaolinite. Montmorillonite had a higher negative effect on the D-W cycle performance of soils compared to kaolinite. This fact could be reflected by the fluctuation of UCS and mass change ratio (Rm). The main carbonation product by three types of carbonated steel slag stabilized soils was calcite, which remained stable after D-W cycles. After carbonation for 18 h, the generated calcite and carbonation degrees for three types of stabilized soils were obtained. In the microstructures of carbonated steel slag stabilized soils, the spindle-like clusters of the generated calcite appeared, which adhered to the surface of mineral particles. The aggregated degrees of the generated calcite in stabilized soils containing clay minerals tended to decrease after D-W cycles. In this work, a new type of carbonated steel slag stabilized soil was studied. The results indicated that the effect of clay minerals on the engineering characteristics of soil should be considered.

Evaluation of Soil Compaction Characteristics at a Construction Site in Al-Khalis City, Northeast of Iraq

Soil compaction characteristics namely optimum moisture content and maximum dry density are frequently used as criteria to control field compaction specifications. This study aims to evaluate the compaction characteristics of soil at a construction site located in AL-Khalis City, northeast of Iraq. Ten soil samples were collected from the study area; five samples were augured to perform the Standard Proctor compaction tests to investigate the relationship between the moisture content and the dry density of the soil. A core cutter method was implemented to collect additional five samples used to determine the field dry density of soil and to calculate compaction ratio. The results showed that optimum moisture content values were ranged from 15.4 to 22.5% while maximum dry density values were ranged from 1.63 to 1.83 g/cm3. The effect of the compaction effort on the compaction curves was investigated. Increasing the compaction effort increases the maximum dry density and decreases the optimum moisture content of the soil. In addition, a linear relationship between the maximum dry density and optimum moisture content (correlation coefficient R2=0.937) is noticed. This relationship is compared with similar relationships from the literature. Finally, compaction ratio, commonly used to evaluate compaction specifications, was calculated. Compaction ratio values indicate that the soil was compacted at the site to satisfactory ranges suitable for engineering construction work.

Modeling the Compaction Characteristics of Fine-Grained Soils Blended with Tire-Derived Aggregates

This study aims at modeling the compaction characteristics of fine-grained soils blended with sand-sized (0.075–4.75 mm) recycled tire-derived aggregates (TDAs). Model development and calibration were performed using a large and diverse database of 100 soil–TDA compaction tests (with the TDA-to-soil dry mass ratio ≤ 30%) assembled from the literature. Following a comprehensive statistical analysis, it is demonstrated that the optimum moisture content (OMC) and maximum dry unit weight (MDUW) for soil–TDA blends (across different soil types, TDA particle sizes and compaction energy levels) can be expressed as universal power functions of the OMC and MDUW of the unamended soil, along with the soil to soil–TDA specific gravity ratio. Employing the Bland–Altman analysis, the 95% upper and lower (water content) agreement limits between the predicted and measured OMC values were, respectively, obtained as +1.09% and −1.23%, both of which can be considered negligible for practical applications. For the MDUW predictions, these limits were calculated as +0.67 and −0.71 kN/m3, which (like the OMC) can be deemed acceptable for prediction purposes. Having established the OMC and MDUW of the unamended fine-grained soil, the empirical models proposed in this study offer a practical procedure towards predicting the compaction characteristics of the soil–TDA blends without the hurdles of performing separate laboratory compaction tests, and thus can be employed in practice for preliminary design assessments and/or soil–TDA optimization studies.

Pengaruh Penambahan Abu Cangkang Kelapa Sawit Pada Tanah Lempung Paccinongang Kabupaten Gowa

Soil has an important role in a highway construction planning that serves to pass the load from the top layer, but not always the basic soil layer is able to function properly. Therefore, in this study was conducted to find out the effect of the addition of oil palm shell ash on clay soil to UCT (Unconfined Compression Test). The type of soil that will be usedfor penelitian is clay soil taken in Paccinongang area, Gowa Regency. The methodology in this study conducted several soil physical properties testing then Kompaksi testing to obtain optimum moisture content value, and Unconfined Compression Test to get strong press value (qu). The results of the study showed that the soil meets the physical properties of clay soil. From The Free Press Strong test on the ash content of the palm shell 0%, 3%, 6%, 9%, 12% and 15% at point 1 the free press strength value decreased from 0% by 0.362% and increased at 9% by 0.424%. Meanwhile, at point 2, it decreased by 0% by 0.445% and increased at 12% by 0.423%. From the Unconfined Compression Test on Paccinongang clay, Gowa Regency with the addition of oil palm shell ash from both samples, there was an increase in the addition of 9% and 12% of normal clay soil.

Improvement in engineering properties of clay soil using waste demolished material

Expansive soil contain the highly active clay mineral in the form of montmorillonite due to which expensive soil swell upto 7% upon adding 1% of water, which may lead to unequal settlement of subsoil. The primary characterisation of clayey soil is which possess very poor shear strength with high shrinkage & swelling. This research paper represent a complete framework to overcome this drawback of highly expansive soil by adding waste material like fly ash and brick waste to clay soil in order to improve it’s engineering properties. Fly ash can be easily obtained from coal combustion plants while brick waste is easily available at demolition area. In this research fly ash is added in different percentages 0%, 4%, 8%, 12%, 16% and brick waste is added 5%, 10%, 15%, 20%, 25% by weight of soil. The results of test shown that the addition of fly ash and brick waste reduces the liquid limit, plastic limit value, plasticity index value, optimum moisture content value, percentage free swell index value and increases the unconfined compressive strength value and California bearing ratio value.

Microbial-Induced Calcite Precipitation Study on the Plasticity and Compaction Characteristics of Lateritic Soil Treated with Bacillus Megaterium in Urea-CaCl2 Culture Medium

An ecofriendly method of soil improvement known as Microbial Induced Calcite Precipitation (MICP) has received significant recognition in the past decade. This study presents a report on the capability of MICP in modifying the plasticity and compaction properties of lateritic soil bio-treated with different suspension densities of a ureolytic microorganisms - Bacillus megaterium (B. megaterium). Specimens were prepared with liquid limit moisture of the natural soil in three mix ratios of B. megaterium (B) and cementation reagent (C) (urea medium): 25 % B: 75 % C, 50 % B: 50 % C and 75 % B: 25 % C. Another set of specimens were prepared at optimum moisture content (OMC) equivalent covering 1/3 pore volume of B. megaterium and 2/3 pore volume of urea medium introduced in three sequences at 6-hour interval to steadily initiate MICP mechanisms. The results of the various mix ratios indicated improvement in plasticity index (PI) with higher B. megaterium suspension density. The best improved PI value was obtained for specimen treated with 75 % B: 25 % C mix ratio at B. megaterium suspension density of 2.40 × 109 cells/ml with an equivalent maximum 5.3 % CaCO3 content. The maximum dry density (MDD) and OMC values marginally increased with higher B. megaterium suspension density as well as calcite content. The micrographs obtained from scan electron microscope (SEM) showed changes from untreated to bio-treated state, which resulted in non-uniform precipitation of calcite in the soil. The variation in elemental quantifications displayed by the X-ray energy dispersive spectroscopy (EDS) validate the formation of calcite within voids and on surface of the soil particles.

Effect of iron ore tailings on the plasticity and compaction properties of selected tropical soils

The workability of any soil, when used as a construction material, is greatly affected by its plasticity and compaction characteristics. This research investigates the effect of iron ore tailings (IOT) on the plasticity and compaction properties of lateritic soil (LTS) and black cotton soil (BCS). Atterberg limit and compaction test using three energies, British standard Light, BSL, British standard Heavy, BSH, and West Africa standard, WAS were carried out. These tests were conducted on mixed ratios of 0, 2, 4, 6, 8, and 10 % of IOT mixed each with LTS and BCS separately. A Statistical conceptual model was developed using Minitab R15 to predict the values of the maximum dry density (MDD) and optimum moisture content (OMC) from the computed laboratory results. Analysis was then carried out on the predicted results using origin pro version 8 to test the efficacy of results obtained. The result of specific gravity test shows increase with IOT concentration. An improvement on the plasticity of the modified soil was noted. The liquid limit for both LTS and BCS decreased with increasing IOT concentration. Values drop from 43.4 to 42.7% for LTS and 56 to 52.6% for BCS at 0 and 10% of IOT content, respectively. Plastic limit increased with increasing IOT concentration for LTS and decreased for BCS. In the case of the Plasticity index, values decreased for LTS and marginally increased for BCS treated with IOT. MDD values increased and thereafter drop for LTS treated with IOT while for BCS values increased from natural up to 10% IOT content. OMC values increased for LTS treated with IOT and decreased for BCS treated with IOT. The effectiveness of the developed model was validated using the values of the correlation coefficient obtained from the statistical analysis, which showed a solid relationship between predicted and measured values. Plasticity index values obtained for IOT stabilized BCS did not meet up to the standard requirement when used as a sub-base and base course material respectively. However, the treatment of LTS and BCS with 8-10% IOT improved the soil properties and can be used for pedestrian walkways.

Application of Mathematical Function to Estimate the Compaction Characteristics of Unsaturated Soils

The study aims to propose a mathematical approach to determine the optimum moisture content (<img src=image/14820636_01.gif>) and the corresponding maximum dry unit weight (<img src=image/14820636_02.gif>) of unsaturated fine-grained clay soils with accuracy. Laboratory tests such as grain size distribution, Atterberg limits, specific gravity, Proctor compaction test, and soil suction measurement are conducted to assess soil properties. The WOP and <img src=image/14820636_02.gif> are determined using the mathematical approach based on differential function (∂) and the graphical method. The differences in optimum moisture content values between the mathematical approach and the graphical method (<img src=image/14820636_03.gif>) values are 0.43 %, 0.36 %, 0.42 %, 0.24 %, respectively for soils PES, BFS, WIS, BES, and induced differences in total suction of 179.17 kPa, 144.00 kPa, 175.00 kPa, 96.00 kPa, respectively for soils PES, BFS, WIS, BES. Moreover, the differences in matric suction are 148.27 kPa, 116.13 kPa, 144.83 kPa, 80.00 kPa, respectively for soils PES, BFS, WIS, BES. <img src=image/14820636_02.gif> and <img src=image/14820636_03.gif> values are smaller than 0.5 % and marginal in the context of saturated soil mechanics. However, the total suction and matric suction values induced by <img src=image/14820636_02.gif> values are significant for unsaturated soils. An accurate estimation of <img src=image/14820636_03.gif> and <img src=image/14820636_01.gif> can be performed on unsaturated compacted soils using the mathematical approach.

Effect of Stone dust and Lime in the Geotechnical Properties of Clayey Soil

Clayey soils are commonly stiff in dry state but lose their stiffness when saturated with water. Soft clays are characterized by low bearing capacity and high compressibility. In this research, stone dust obtained from stone processing area used for Stabilization of clayey soil with lime. Thus, the effectiveness of using stone powder and lime in stabilizing fine-grained clayey soil (CL) was investigated in the laboratory. The soil samples in natural state and when mixed with varying percentages of lime and waste stone powder were used for the laboratory tests that included Atterberg limits tests, standard Proctor compaction tests, unconfined compression tests and California bearing ratio tests. The value of maximum dry density, Unconfined Compressive Strength and California Bearing Ratio decreased with increase in % of stone dust and lime. The Optimum Moisture Content value remain same with increasing stone dust content and lime.

Effect of Elapsed Time after Mixing on the Strength Properties of Lime–Iron Ore Tailings Treated Black Cotton Soil as a Road Construction Material

The study evaluated the effect of elapsed time after mixing on the strength properties of lime and iron ore tailings (IOT) treated black cotton soil (BCS) (an expansive tropical black clay) as road construction material. BCS was treated with 0, 2, 4, 6, and 8% lime and 0, 2, 4, 6, 8, and 10% IOT content by dry weight of soil. Tests carried out include Atterberg limits, compaction, unconfined compressive strength (UCS), California bearing ratio (CBR) (unsoaked condition), and microstructure of specimens. Statistical analysis was done using MINI-TAB software. Results show that the liquid limit (LL) of BCS–lime–IOT mixtures decreased with increase in lime and IOT content. The LL values of all the treated BCS increased between 0 and 1 h elapsed time after mixing. On the other hand, the plastic limit (PL) of BCS decreased with increase in lime and IOT content while the plasticity index (PI) decreased from 27.7 to 22.9% for 0% lime/0% IOT content and from 30.6 to 26.6% for 0% lime/10% IOT content. Maximum dry density (MDD) of BCS increased while optimum moisture content (OMC) decreased with higher IOT content. The natural BCS recorded OMC value of 25.6% decreased to 15.2% for 8% lime/10% IOT treatment. The strength (i.e., UCS and CBR values) increased with increase in lime/IOT contents between 0 and 2 h elapsed time after mixing. Peak values were recorded for 8% lime/8% IOT treatment for all lime content considered. Regression analysis shows a strong relationship between the strength properties and the soil parameters. An optimal 8% lime/8% IOT treatment of BCS for elapsed time after mixing not exceeding 2 h was established and is recommended as sub-base material for low-trafficked roads.

Analisis Sandcone Test (AASHTO T 191 dan ASTM D 1556 64) Pada Peningkatan Jalan Jepara – Kedungmalang – Pecangaan

Concrete road works on the improvement of the Jepara - Kedungmalang - Pecangaan road are the activities of the Publick Works Department of Highways in Central Java Province. Quality control in a building structure work is very important to support the strength of the structure. In planning the road structure, it is necessary to have density of soil and foundation layers that meet the requirements. To get the value of the degree of density that is from the sandcone test where in the sandcone test there are several standart methods or references for example from AASHTO T 191 and ASTM D 1556 - 64. In this study the aims is to obtain the value of the degree of density, how big is the difference between the AASHTO T 191 standart and ASTM D 1556 - 64, and know the water content. From the test result, the optimum moisture content value is 6.5%, dry density is 2.17gr/cm3, the value of the degree of density mostly ranges from "&amp;gt;100%, and the minimum water content value is 5.00% maximum water content is 6.7%.

Comparison of Reduced Modified Proctor vs Modified Proctor

The compaction characteristics between reduced modified Proctor and modified Proctor tests have been compared. The results show that maximum dry unit weight values are comparable for both the tests but optimum moisture content values differ slightly more. For both the tests: optimum moisture content was found to correlate best with liquid limit, and the relationship for maximum dry unit weight with optimum moisture content was found to be almost the same. Since reduced modified Proctor requires less time and 40% less compaction energy as compared to modified Proctor test, it can be considered as a suitable alternative to the modified Proctor test.