Subbase Course Research Articles

Resource Assessment of Limestone Based on Engineering and Petrographic Analysis

The China-Pakistan Economic Corridor (CPEC) is a massive in-progress construction project in Pakistan that connects more than 70 countries via multiple trade channels such as highways, railways, roads, and fiber optics. This project also involves the development of local infrastructure and industrial zones in Pakistan, which demands the discovery of new resources of aggregate to facilitate the construction. Therefore, physical characterization research was carried out on the Kirman hill region (Jurassic limestone), District Kurram, Pakistan, to investigate their suitability for utilization as construction materials using site investigation and laboratory studies. The results outline that all typical engineering parameters are within acceptable limits set by international standards like BS, ASTM, and AASHTO. Bituminous tests revealed that Jurassic limestone is appropriate as an aggregate for asphalt wearing coarse. Likewise, the petrographic study performed shows proper matching with engineering tests. The petrographic analysis of Jurassic limestone showed a minute amount of deleterious content; as a result, it is resistant to Alkali silica reaction (ASR) and Alkali carbonate reaction (ACR) expansions. Based on engineering and petrographic analysis, the Jurassic limestone, Kirman hill region, District Kurram, Pakistan is recommended as a potential aggregate for (i.e., base course, subbase course, cement concrete, and asphalt) and other mega and minor civil construction projects. Doi: 10.28991/CEJ-2022-08-03-02 Full Text: PDF

Ferrochrome Slag characterization and its compatibility with Quarry dust in Flexible pavement

Exhaustion of locally available materials and increasing hauling charges gained the potential for the exploration of cost-effective alternative materials in the construction industry. Broad endeavours have been made over numerous years on the utilization of industrial waste, yet scant exploration is being done on ferrochrome slag. Ferrochrome slag is an industrial by-product obtained from stainless steel production. Several highway laboratory tests on the characterization of ferrochrome slag are carried out, and the physical and mechanical properties of ferrochrome slag are observed to fulfil MoRTH specifications. Deficiency of fines is observed in the gradation of ferrochrome slag, so quarry dust is incorporated for mechanical stabilization. Ferrochrome slag and quarry dust are blended in different proportions to check the gradation suitability as sub-base and base courses in flexible pavement. Modified Proctor Method of compaction is performed for the ferrochrome slag and quarry dust combinations to carry out the California Bearing Ratio (CBR) test at Maximum Dry Density (MDD) and Optimum Moisture Content (OMC). Studies have shown that the combinations of ferrochrome slag and quarry dust in 70/30 and 60/40 proportions are well graded and have reached the required gradation for use as cement-treated sub-base and base layers in flexible pavement.

Evaluating the durability of stabilized conventional granular material with Pond Ash and lime used as subbase course of flexible pavement

The backbone of power capacity addition in India has always been the coal-based thermal power generation. The thermal power stations has been fueled by the coal produced in India, which are predominantly low grade with 30–22% ash content. The ever-growing disposal problem of the Pond Ash (PA) generated by these thermal power stations, on account of using the high ash content coal having, granular particle sizes has become a huge issue. The associated environmental hazard is the primary coencern along with the dumping zone, which covers large hectares of land over a prolonged period. On the other hand, a strictly regulated sand mining scenario restricted the progress of the construction activities in the related field. So effective reuse of such industrial waste by replacing the conventional granular material, may overcome the environmental and health hazard, as well as speed up the construction activities. Moreover, the PA will find effective bulk usage. Prior Investigational works have shown improvement in the geotechnical properties of stabilized coal combustion ash. This study involves sand and PA blended in varying proportions from 0% −100% at an increment of 10% by weight of sand, with addition of lime (0%, 1%, 2%, 3%, 4%, 5%, 6%, 7% and 8% by weight of sand) as stabilizer. The un-soaked bearing ratio of sand – PA optimum mix with different lime content was observed. The results indicated a considerable rise in the bearing ratio up to 4% lime content which gradually reduces on further addition. Experimental results showed a maximum CBR of 32.85% for standard compaction un-soaked sample. Sand – PA – Lime samples were further tested for their UCS values after curing them for 7, 14, and 28 days. The results maxed out at 0.8 MPa for 28 days curing at 4% lime content. Slake Durability Indices showed high to medium–high durability value for the optimum mix. Chemical composition of lime and PA along with XRD and FESEM of PA sample was also conducted to characterize the sample. The test outcomes satisfied the MORD and MORTH requirements to use the sand (71%): PA (25%): lime (4%) as suitable subbase material for pavement foundation construction as cost-effective mix proportion.

Geotechnical Characteristics of Benin Formation, Owerri Imo State, Nigeria

A good road network consists of a constant stretch of asphalt laid down for a smooth ride. The spot in the smooth ride on the pavement is commonly referred to as "pavement failure." Soil type, load bearing capacity of materials, zone of vulnerability, resistance to permeation, compressibility, shrinkage limit, and other details are frequently required in order to construct a very good and solid foundation for the planned bridge site. In Nigeria, numerous factors contribute to the failure of road construction projects. They are primarily insufficient research on subgrade and other pavement materials (sub-base and base courses) prior to the start of road projects; flawed engineering, including a poor drainage system and supervision throughout road construction; and shoddy workmanship that was superimposed with asphaltic concrete to improve strength. Within the Niger Delta basin, the study area is located between latitude 5.485°N and longitude 7.035°E. The Benin Formation underpins the study area. It is composed primarily of friable sands, conglomerates, very coarse sandstone, and isolated gravel units, as well as intercalation of Pliocene to Miocene shale/clay lenses. Natural Moisture Content (NMC), Linear Shrinkage (LS), Particle Size Distribution, and California Bearing Ratio were among the laboratory tests performed on samples collected at failed and stable sections of some selected road segments (CBR). When compared to the stable sections, the NMC along the failed sections was on the high side (ranging from 13.11 percent to 26.89 percent) (ranging from 11.11 percent to 16.40 percent). The majority of the tested soils passed the 0.075mm sieve with a percentage greater than the Federal Ministry of Works and Housing's maximum of 35% for subgrade materials. The maximum dry density (MDD) for the samples at failed and stable sections was 1550 kg/m3 to 1860 kg/m3; 1650 kg/m3 to 1980 kg/m3; and the Optimum Moisture Content (OMC) was 8.30% to 20.30%. The soaked CBR values ranged from 2 to 17 percent, while the unsoaked values ranged from 4 to 25 percent.

The impact of alccofine inclusion on the engineering properties of bentonite

This paper assesses the engineering properties of bentonite-alccofine mixtures through a series of compaction, consistency limits, and unconfined compressive strength tests along with the SEM-EDX analysis. The alccofine content in the mixtures were 0%, 2%, 4%, 6%, 8%, and 10% by the dry weight of the specimens. Compaction test results reveal an increase in the dry unit weight and a decrease in the optimum moisture content up to 8% inclusion of alccofine. With the increase in alccofine content, the consistency limits of the mixes decrease. Furthermore, the maximum values of unconfined compressive strength, secant modulus, peak strain energy, deformability index, shear modulus, and resilient modulus of 28 days cured specimens of bentonite-alccofine mixtures prepared at ω opt - 3%, ω opt, and ω opt + 3% are observed for specimens with 6%, 8% and 8% alccofine content, respectively. The results of the morphological study reveal an increase in the Ca/Si ratio and a decrease in the Si/Al ratio up to an alccofine content of 8% in the bentonite. However, the Si/Al ratio increases beyond an alccofine content of 8%. Based upon the test results and comparison with various Indian standards, the quantity of alccofine to be added in bentonite should be in a range of 6%–10%, for its application in the construction of embankments, base, and subbase courses of rural roads.

Evaluation of the influence of compaction energy on the resilient behavior of lateritic soil in the field and laboratory

This article presents the study of the resilient behavior of three soil horizons from a deposit of lateritic soil employed in a pavement structure in Rio Grande do Sul, Brazil. The use of lateritic soils in pavement layers is a common practice in Brazil and due to its peculiarities, its behavior must be investigated. The methodology consisted of physical and chemical characterization and resilient modulus determination. Samples from the three horizons, compacted at standard, intermediate and modified energy, were analyzed. In addition, undisturbed samples extracted from the interior and top layer of the embankment were submitted to repeated load triaxial tests for resilient modulus determination. The results indicated that the soil exhibit good behavior for pavement subgrade applications, perhaps as subbase or base course layers. The compound and universal models yielded the best correlation coefficients. Furthermore, the results showed that as the compaction energy increased, the resilient modulus also increased, as long as they are within the optimum water content and compaction degree limit. However, when subjected to immersion in water for four days, the resilient behavior decreased about 73% in relation to unsaturated samples.

An experimental investigation on geotechnical properties of a clayey soil stabilised with lime and zeolite in base and subbase courses

Zeolite is often exploited to reduce the consumption of lime in the treatment of problematic clays and to help further enhance the soil stabilisation process in pavement base and subbase courses. For the mix design of the proposed pavement materials, 8% lime was first opted, according to pH tests, as the optimum content and its different portions were then replaced by zeolite inclusion. A comprehensive set of Atterberg limits, standard Proctor, unconfined compression and unconsolidated undrained (UU) triaxial tests was performed on lime and zeolite stabilised specimens. Zeolite addition into the mixture increased the maximum dry unit weight and decreased the optimum moisture content. The least plasticity index and the highest unconfined compressive strength were attained at 25% of lime replacement with zeolite, deemed to be the optimum mixing content. Results of UU triaxial tests on the optimum mixtures also confirmed the marked improvement of shear strength parameters.

Studying the Early Cracking Behavior of Asphalt Concrete Base Course

In Iraq, there are some asphalt concrete mixtures suffer from appearing of cracking and deformation immediately after finishing the construction of a base course. In the flexible pavement, the pavement is considered to be degraded after opening to traffic by repeated traffic loading, climatic conditions, aging of asphalt mixture, etc. Crack plays a critical mode in pavement degradation. Several experimental studies have been carried out to gain a deeper understanding of the environment and weak construction monitor the action of pavement fractures. However, one downside of these previous studies was that the majority of them were carried out in a laboratory environment. A trial road section was studied after finishing base course construction by monitoring the early cracking. The major causes of appearing the early cracking have been investigated and debated. In this survey, three trial road sections with defined asphalt layers were considered. These trial sections were constructed with local materials brought from Nasrya refinery and Najaf quarry. On the basis of the findings obtained, two sections have deteriorated, while the third one was made as control for comparison purposes The observed early cracking could be attributed to the asphalt cement type and poor construction procedure occurring in an asphalt base layer as a result of low underlying sub-base course type and specifications.

A structural design for semi-rigid base asphalt pavement based on modulus optimization

The early damage of the semi-rigid base asphalt pavement is related to the pavement structure modulus's unreasonable matching. In this study, three typical pavement structures were selected to analyze the pavement structures' influence on the pavement service life. A three-dimensional finite element pavement structure model was established. The independent variables are subgrade modulus, base course modulus, and subbase modulus. The deflection, the bottom tensile stress, and maximum shear stress were chosen as the evaluation indexes. The effect of the modulus on the mechanical response of the pavement structure was analyzed. The optimal modulus combination of the pavement structure was determined through multi-factor range analysis. The mechanical response and fatigue life before and after the optimization pavement structure were compared. The results showed that the field measured modulus of Structure 1 and 2 was higher than the design modulus. Moreover, while the modulus of base course and subbase course was increased, the deflection gradually reduced. The base course's bottom tensile stress and the subbase were increased, and the maximum shear stress was basically unchanged. After the modulus combination optimized pavement structure, the mechanical response was significantly reduced. The fatigue life based on the deflection and bottom tensile stress, and the laboratory normalized fatigue equation were significantly increased. By the combination of fatigue performance of pavement materials and pavement structure, it was possible to provide an effective optimization method for the design of semi-rigid base asphalt pavement in this research work.

Effect of compaction energy on grain breakage of CDW, local soil and soil-CDW mixtures

ABSTRACT The use of construction and demolition wastes (CDW) as alternative material in engineering has proved promising applications, especially in pavement layers. However, the high grain breakage of this material has led to uncertainties regarding its performance. The present study assessed the effect of compaction energy on grain breakage of CDW, comparatively to a local sandy-clay (SC) soil with gravels, and mixtures of soil-CDW. Other geotechnical properties were also evaluated for application in pavements. Results showed the feasibility of using CDW as pavement layer material when compacted using modified energy. The local sandy-clay soil was not appropriate for pavement layers, while soil-CDW mixture improved soil geotechnical characteristics, allowing its use as subbase course. Grain breakage analysis, based on a statistical approach, showed that CDW undergoes greater particle size distribution change, not altered by compaction energy increase. Results confirmed that soil-CDW mixture presented superior performance for pavement layers.

Pavement Design of Coal Mine Hauling Road in Indonesia using California Bearing Ratio (CBR) data

Mine activities in the open-pit method are usually dominated by digging-loading-hauling. This hauling road is the infrastructures that is highly essential in mine area and serve as main linkage some locations. Design of the road requires careful attend in avoidance of failure in construction and disruption in production activities. Field investigations such as insitu CBR testing and laboratory testing (Proctor Modified and CBR laboratory) were chosen to determine the geotechnical parameters of soils that needed in the design of hauling road. The average value of the laboratory CBR testing at 0.1 inch penetration was 16%. The modified type of proctor test comprise some parameters such as the average value of the maximum dry density was 1.64 gr/cm3; the maximum wet density was 1.97 gr/cm3; the average value of dry unit weight was 16.07 kN/m3; saturated unit weight was 19.30 kN/m3; optimum moisture content was 20.2%. The average value of insitu CBR testing at 0.1 inch penetration was 19%. The average load of tire pressures on the front and rear wheels is 7000 lbs. The ability of road to carry the load should have the bearing capacity > 20800 psf = 144.44 psi = 20.95 kPa. The thickness of each pavement layer is as follows: 17 inches of sub grade layer; 2 inches of sub-base course layer; 15 inches of base course layer; 5 inches of surface course layer.

Numerical study using stiffness parameters on the nonlinear behavior of RCA pavements under heavy traffic loads

The use of the recycled concrete aggregates (RCA) obtained from construction and demolition wastes not only reduces the demand for natural aggregate, which ultimately leads to economical and eco-friendly designs, but also improves the long-term performance of a conventional flexible pavement. This study aims to investigate the effects of using 100% RCA in the pavement subbase and base courses on the mechanical behavior of the flexible pavement. This study is divided into two stages, i.e., a laboratory study characterizing the properties of RCA and a numerical analysis evaluating the long-term performance of RCA under heavy traffic load conditions. In the laboratory study, along with the determination of the classical geotechnical properties of base and subbase samples, the stiffness properties of the samples were obtained by applying the resilient modulus test (RMT) and permanent deformation test (PDT). Then, by comparing the results of the three different constitutive models, the result of the more appropriate model was selected. In the second stage, the plastic deformation (rutting) of the pavement courses and the maximum value of deflection when subjected to multiple wheel loads were determined using a 3D nonlinear numerical method. Based on the experimental results, RCA demonstrated higher resilient modulus and lower plastic deformation compared to that of conventional base and subbase materials. Regarding the long-term behavior, the permanent strain rate of the samples was reduced at an approximately constant level during the first load cycles. Additionally, the numerical analysis results indicated that the mechanical performance and rutting values of the base and subbase courses constructed using 100% RCA met the specified requirements.

GEOTECHNICAL CHARACTERIZATION OF ALLUVIAL SOIL AS AN ALTERNATIVE ROADWAY CONSTRUCTION MATERIAL

The rapid infrastructure development in the Philippines over the past years poses problem on construction cost due to the limited supply of suitable road foundation materials within economic haul distances. An economic and sustainable solution is to use locally available but suitable materials. This study utilized the naturally-occurring alluvial soil along the Angat Riverbanks as a potential road foundation material. Geotechnical characterization of the alluvial soil was performed including direct shear and California bearing ratio (CBR) tests. The findings of the index properties showed that the alluvial soil is 92% sand, non-plastic, and was classified as poorly-graded sand. A CBR of 41% makes the river sand a suitable subbase course material. However, the sample failed on the gradation requirement for subbase application due to lacking of coarse aggregates. From the direct shear tests, the soil showed brittle failure that yields peak shear stress and dilative volume change behavior. The critical state friction angles for dry and saturated conditions are 37.52° and 36.61°, respectively. Morphological analyses were also performed to further evaluate the material composition of the alluvial soil. The sedimentological analysis found that the sample is both texturally and compositionally immature. Sediments are angular to subrounded and moderately sorted. Correspondingly, the SEM-EDX revealed flocculation with flakey particles and small inter granular voids that justifies the shear strength of the sand. It is recommended to blend coarse aggregates with the alluvial soil to meet the gradation requirements and possibly increase its bearing strength for base course applications.

Analisis Tebal Perkerasan dan Biaya Dengan Software Faarfield Pada Landas Pacu BIJB Kertajati

An airport that was constructed and used for air traffic certainly repented of the action of thickness analysis and evaluation of thickness that could withstand the burden of traffic movements. Accordingly, the purpose of this research is to analyse runway pavement thickness that used is FAA Method Advisory Curcular no. 150/5320-6E through FAARFIELD software and the result is a total thickness of 814, 9mm with surface course thickness of 200 mm, base course thickness of 127 mm, and subbase course thickness of 487,9 mm. Evaluation thickness the stucture strength which is PCN score through two methods ICAO and FAA based on AC 150/5335-5C by using COMFAA software and by calculating ACN score which is the number that become a certain aircraft limitation toward the pavement.PCN score ICAO method is 89/F/C/X/T < ACN is 89,3 and FAA method is 101,4/F/C/X/T > ACN is 89,3. The result of mininum construction cost analysis from 5 comparative is a method of software FAARFIELD of Rp.326.252.664.418,00.

Resilient and permanent deformation behaviors of construction and demolition wastes in unbound pavement base and subbase applications

The reuse of construction and demolition wastes (C&D wastes) as unbound granular materials (UGMs) to construct pavement base and subbase courses is of great potential, while the cyclic behaviors of unbound C&D wastes under traffic loadings still lack the support of test data. To investigate the traffic-induced resilient and permanent deformation behaviors as well as the shear and particle breakage properties of the unbound recycled concrete aggregate (RCA) & recycled clay masonry (RCM) blends, a series of consolidated drained, resilient deformation and permanent deformation tests by a large-scale dynamic triaxial apparatus were performed. The RCM content in two blends made by different mixed methods was emphasized, and the factors of gradation, confining pressure and cyclic deviatoric stress amplitude were also taken into consideration. Test results show that RCM content makes great influences on the particle breakage, resilient modulus, permanent axial strain and shakedown behavior of unbound RCA & RCM blends, and the influences show obvious differences between the two mixed methods. The peak triaxial strength, particle breakage level and resilient modulus of blends 1 (B1) are generally larger than those of blends 2 (B2), and the influence of confining pressure and cyclic deviatoric stress amplitude on resilient modulus are related to the mixed method but unrelated to RCM content. The popular modified K-θ model is employed to predict Mr of B1 and B2, and the reference ranges of the regression coefficients with respect to RCM content are obtained. Based on the results, it is evaluated that when RCM content is below a certain extent (e.g. 30%), B1 perform better (and the best at around RCM content of 10%) as pavement base and subbase courses in regard to shear strength, resilient modulus and permanent strain. However, as the RCM content continues to increase, B2 may be better than B1 considering the overall performance of cyclic properties.

Stiffness Properties of Recycled Concrete Aggregates as Unbound Base and Subbase Materials Under Freeze and Thaw Cycles

Freeze and thaw processes are mostly observed in cold regions and impact the short- and long-term performances of road pavements. Thus, freeze and thaw processes should be considered when designing and constructing roads due to the potential change it will cause to the structure, arrangement and properties of the materials used in road construction. This study attempted to understand the effect of freeze and thaw (F–T) cycles on the stiffness properties of recycled concrete aggregates (RCAs). For this purpose, base and subbase samples prepared with RCAs are subjected to varying numbers of F–T cycles, and a series of resilient modulus and permanent deformation tests are conducted. Moreover, the different models were applied to estimate the resilient modulus and permanent deformation, and the suitability of each model was discussed. The experimental study results indicate that the geotechnical engineering properties of RCAs originating from Istanbul-Turkey are suitable for utilization as unbound base or subbase course materials. In the stiffness assessment, the highest resilient modulus was obtained after 5 F–T cycles and then decreased but was still higher than that of the nonfrozen samples except the subbase sample exposed to 20 F–T cycles. Lower plastic strain values were obtained for the base samples, and after F–T exposure, no drastic changes were observed in the permanent strain increments for the base materials, as seen in the subbase samples. Most of the RCA samples exposed to F–T cycles accumulated permanent strains with plastic creep behavior based on the shakedown theory.

Timber as a Pavement Construction Material: Design and Application

Roads are one of the most important infrastructure to increase economic growth, accelerate the flow of goods and communication between regions. Therefore, in building road infrastructure it is necessary to pay attention to using materials which appropriate the specifications. Limited pavement materials in an area or region is one of the problems faced by government. It is causes that very important to looking for replacement material that can be used to overcome the problem of material limitations. This study use Bus timber as a substitute material for aggregate in subbase course. It is considerate that Bus timber is often used in timber bridge construction. Bus timber will be made as a raft foundation. At the end of this study, the expected result is that bus timber can be used as pavement material especially for subbase course.

CBR Characteristics of Cementitious Graded Gravel Soils by Curing Methods

The service life and performance of pavements mainly depends on the quality of materials used in the construction, Majority of local soils in their natural form lack in desired strength and durability required for the intended constructions, they are to be improved through the standard process of stabilization to make them suitable as one of the construction material, The cement treated soils are widely used in granular base and sub-base courses of pavements as construction material due to batter strength and durability. The current study there are three different locally available gravel soils has been selected and tested for their physical properties, compaction and strength characteristics, as per the test results the soils were classified as GM-GC, GC-1 and GC-2 and CBR% values were 28, 26 and 25 respectively, as per MORTH specifications CBR%>35 to use as base course material, hence the selected soils could not be used as base course material due to its low CBR values, so that cement stabilization has been used to improve the CBR% values. The different percentages of cement 0%, 1 %, 2% 15% were added to GM-GC, GC-1 and GC-2 soils with gradation of G-50%(26.5 mm to 4.75mm IS-Sieves) and G-50% (4.75mm to 0.002mm IS-Sieves) and tests were conducted to assess the compaction and strength characteristics by varying curing methods as 7days moisture, 7days water and 7days partial curing (3days maisture+4days water). As per the experimental results, it observed that among selected soils GM-GC soil has achieved CBR% of 85-101 with addition of 6-7% of cement under the partial curing (3M-4W) for 7days, it is more than appropriate to use this soil as base course material in road construction as per the MORTH (CBR %> 35)specifications.

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.

Stabilization of lateritic soil by ladle furnace slag for pavement subbase material

The effect of ladle furnace slag or LFS on the mechanical properties of the lateritic soil mixes for use as a subbase course material in the pavement structure was investigated. The lateritic soil grade E with the lowest mechanical properties was studied by mixing the LFS in the ratios of 5 to 12 wt%. The pavement material criterion of the Thailand Department of Highways was used to qualify the liquid limit, plasticity index, the California bearing ratio, and the swelling index of the mixed lateritic soil with the LFS. An increase in the California bearing ratio of the lateritic soil under the soaked condition was found to be positively correlated with the increasing LFS. Meanwhile, the liquid limit and the plasticity index decreased, leading to a decrease in the swelling index of the lateritic soil containing LFS. Using LFS reduced the total fine-particle ratio in the soil mixture but effectively enhanced the degree of compaction and swelling tolerance in the lateritic soil mixture. 10 wt% LFS is strongly recommended as a minimum admixture in the lateritic soil due to the highly improved plasticity and the mechanical properties of the lateritic soil for a subbase course material selection under the standard specifications.