Road Base Construction Research Articles

The Use of Waste Materials Red Mud and Fly Ash as Road Embankment Fill

This study provides a comprehensive evaluation of red mud as a sustainable material for road base construction, particularly in combination with bottom ash. Red mud, a by-product of the Bayer process used in alumina extraction, is known for its high alkalinity and heavy metal content. For this reason, this waste material causes environmental challenges. Red mud sourced from the Eti Aluminum Factory in Seydişehir, Konya (Turkey), was stabilized with bottom ash. Then, these waste materials were tested through a number of experiments, such as in relation to their Atterberg limits, compaction characteristics, unconfined compressive strength (UCS), California bearing ratio (CBR), and microstructure through a scanning electron microscopy (SEM) analysis. The results highlight that the UCS of stabilized red mud samples significantly improved with the addition of bottom ash and longer curing periods. Specifically, the UCS values increased from 0.5 MPa to 2.5 MPa after 28 days of curing. Moreover, RM specimens stabilized with 25% bottom ash achieved a CBR value of 146.64% after 28 days, far exceeding Turkey’s road fill material requirement, which mandates a minimum unsoaked CBR value of 15%. These findings indicate that red mud stabilized with bottom ash not only meets but exceeds the structural requirements for road base materials. This approach provides a sustainable solution for the environmental management of red mud while contributing to infrastructure development. Through the recycling of these industrial by-products, this study presents a viable method to reduce waste and support economic and environmental sustainability in road construction projects.

Sustainable development of pavement base stabilization using future road base material (FROBM)

Sustainable road construction has emerged as a critical issue in assessing natural resources and urban development. With the rapid expansion of pavement networks to meet growing traffic demands, road base construction relies heavily on the consumption of natural aggregates and Ordinary Portland Cement (OPC) through the cement-treated base (CTB) technique. This practice contributes to the global warming and greenhouse gas (GHG) emissions associated with road construction. This study investigated a novel road base material, Future Road Base Material (FROBM), which emphasizes both eco-friendliness and economic advantages. Fine crushed rock (FCR) served as the parent aggregate and was modified with a chemical binder comprising 4% of the FCR weight. The proposed sustainable cementitious material, functioning as a non-OPC binder, incorporated fly ash and hydrated limestone as pozzolanic materials, along with sodium hydroxide (NaOH) as an alkali additive. An asphalt emulsion (AE) was employed as a special additive to enhance crucial pavement engineering properties. Through life cycle analysis (LCA), the construction activities and material acquisition of each stabilized base technique were evaluated in terms of project costs and carbon footprints. The non-OPC binder offered sufficient compressive strength for a stabilized base course. Furthermore, the addition of AE improved the elastic modulus and modulus of rupture of the non-OPC binder-stabilized mixture. Utilizing a non-OPC binder and AE in the base layer provides advantages in terms of construction cost and environmental impact. Although the costs increased slightly, the GHG emissions were reduced by approximately 30% compared to conventional base materials, with equivalent functionality and service life for road construction. The proposed stabilizing agent reduced the operational processes and demand for natural aggregates compared with the unbound FCR base course. Road-base stabilization using a non-OPC binder and AE represents an innovative approach to mitigate waste in coal mining and power plant industries by transitioning to a cleaner product. The concept of the FROBM serves as a valuable guideline for the development of future sustainable pavement materials.

Eco-friendly road construction: Harnessing fly ash and waste marble powder for sustainable road construction using a fuzzy logic assessment

<p>More than seventy percent of mineral gets wasted during mining and polishing processing, and all this dumped waste threatens the aquifer. Utilizing this waste in construction works helps to reduce the environmental effects. This research aims to protect the environment by implementing mineral waste collected from neyveli lignite fly ash with waste marble waste powder in road-base construction. Accessing the different required combinations of mineral admixtures through laboratory tests poses a challenge. This study identify a suitable combination of fly ash with waste marble powder for assessing the compaction properties and compressive strength for road base construction through fuzzy logic. A fuzzy model was created by using MATLAB software. It consists of two input and four output parameters, fly ash and marble waste powder are the input parameters with four different combinations, and the output factors are dry unit weight, water content, unconfined compressive strength and CBR. The fuzzy model was evaluated with laboratory test results. The study concluded that only a minimum percentage of deviations between the predicted strength and actual results from the laboratory. In future research, this study helps to reduce the time and cost of laboratory tests for different combinations.</p>

Utilization of coal-based synthetic natural gas slag as road base construction material through geopolymerization

The development of the Coal-based synthetic natural gas industry inevitably produced lots of slags. The application of coal-based synthetic natural gas slag (CSNGS) to road base not only effectively alleviated the accumulation and pollution of CSNGS, but also reduced the consumption of resources, which had significant economic and social benefits. However, CSNGS has a higher crushing value and water absorption, thus its mix design, mechanical properties and pavement performance must be further investigated when applied as the raw material of novel cementing material and aggregate. The purpose of this study is to investigate and comparatively analyze the optimal mixing ratio and mechanism of the strength of CSNGS applied in road base. For this, this study prepared the precursor of geopolymer by milling CSNGS into powder and mixing it with 20% cement. Then sodium hydroxide and sodium silicate were used as alkali activators to activate CSNGS, and the 7d unconfined compressive strength was used as the evaluation index to develop the optimal mix ratio of coal-based synthetic natural gas slag geopolymer (CSG). CSNGS with particle sizes ranging from 0 to 4.75 mm and 0 to 9.5 mm were used as aggregates to replace natural stones, then the cement and CSG were selected respectively to stabilize the slags-aggregates, and the relevant tests were carried out to investigate the mechanical and road properties. The results showed that the performance of CSG stabilized aggregates was lower than cement stabilized aggregates in the tests of unconfined compressive strength, splitting strength, unconfined compressive modulus of resilience, dry-wet cycles, and freeze–thaw cycles. The performance of the mixture deteriorated with the incorporation of CSNGS when the cementitious material was cement. The temperature shrinkage test found that the shrinkage of CSG stabilized specimens was less than cement stabilized specimens, which indicated that CSG had excellent anti-cracking potential. In addition, the temperature shrinkage coefficients of mixtures with different CSNGS dosages varied with temperature when the cementitious material was cement. Finally, to further verify the macroscopic test results, this study combined with scanning electron microscope (SEM) test to deeply analyze the strength formation mechanism of several mixtures.

Characteristic evaluation of geopolymer based lateritic soil stabilization enriched with eggshell ash and rice husk ash for road construction: An experimental investigation

In line with sustainable development, the road sector has initiated the use of agro-wastes in road construction to preserve natural resources, which have been commonly used in conventional construction. In that sense, this study investigates the merits and demerits of incorporating eggshell ash (ESA) and rice husk ash (RHA) into geopolymer based lateritic soil stabilization for roadbase construction. Atterberg limits, modified Proctor compaction, unconfined compressive strength (UCS) tests were conducted on lateritic soil samples stabilized with cement or geopolymer that comprises of the combination of ESA, RHA and sodium hydroxide solution (NaOH). Results from the experimental study revealed that an increase in ESA substitution level reduced the plasticity index of lateritic soil. Maximum dry density was slightly reduced in all soil mixes stabilized with ESA, RHA and NaOH. With reference to cement stabilization, UCS showed a marginal reduction of 8.2 and 13.2% in geopolymer combinations of 3E1R1N (3% ESA + 1% RHA + 1% NaOH) and 2E2R1N (2% ESA + 2% RHA + 1% NaOH), respectively. Notably, out of all mixes, the mix combination of 3E1R1N and 2E2R1N produced the lowest cost to strength and embodied energy to strength ratio, and relatively lower CO2 emission to strength ratio. The authors believe that the proposed geopolymer stabilization method would be a competitive alternative to cement based lateritic soil stabilization for roadbase construction.

Investigation on the Suitability of High Clay Lateritic Soils Stabilized with Cement and Rice Husk Ash for Use in Road Base Construction: A Case Study of Juja Town

Investigation on the Suitability of High Clay Lateritic Soils Stabilized with Cement and Rice Husk Ash for Use in Road Base Construction: A Case Study of Juja Town

Mechanical Performance of Laterite Soil Stabilized with Cement and Grewia Bicolour Bark Juice for Road Base Construction

Mechanical Performance of Laterite Soil Stabilized with Cement and Grewia Bicolour Bark Juice for Road Base Construction

Crushed stone partially substituted with shredded-waste tyres of motorcycles for low-volume road base construction: a feasibility study in Sri Lanka

Crushed stone partially substituted with shredded-waste tyres of motorcycles for low-volume road base construction: a feasibility study in Sri Lanka

Influence of Asphalt Emulsion Inclusion on Fly Ash/Hydrated Lime Alkali-Activated Material.

Supplementary cementitious materials have been widely used to reduce the greenhouse gas emissions caused by ordinary Portland cement (OPC), including in the construction of road bases. In addition, the use of OPC in road base stabilization is inefficient due to its moisture sensitivity and lack of flexibility. Therefore, this study investigates the effect of hybrid alkali-activated materials (H-AAM) on flexibility and water prevention when used as binders while proposing a new and sustainable material. A cationic asphalt emulsion (CAE) was applied to increase this cementless material’s resistance to moisture damage and flexibility. The physical properties and structural formation of this H-AAM, consisting of fly ash, hydrated lime, and sodium hydroxide, were examined. The results revealed that the addition of CAE decreased the material’s mechanical strength due to its hindrance of pozzolanic reactions and alkali activations. This study revealed decreases in the cementitious product’s peak in the x-ray diffraction analysis (XRD) tests and the number of tetrahedrons detected in the Fourier transform infrared spectroscopy analysis (FTIR) tests. The scanning electron microscope (SEM) images showed some signs of asphalt films surrounding hybrid alkali-activated particles and even some unreacted FA particles, indicating incomplete chemical reactions in the study material’s matrix. However, the H-AAM was still able to meet the minimum road base strength requirement of 1.72 MPa. Furthermore, the toughness and flexibility of the H-AAM were enhanced by CAE. Notably, adding 10% and 20% CAE by weight to the hybrid alkali-activated binder produced a significant advantage in terms of water absorption, which can be explained by its influence on the material’s consolidation of its matrices, resulting in significant void reductions. Hence, the outcomes of this study might reveal an opportunity for developing a new stabilizing agent for road bases with water-prevention properties and flexibility that remains faithful to the green construction material concept.

Structural Performance of Laterite soil Stabilised with Cement and Blue Gum (Eucalyptus Globulus) Wood Ash for Use as a Road base Material

This study examines the effect of partially replacing cement with blue gumwood ash (BGWA) in stabilizing laterite soil to be used as a potential road base material. Initially, Ordinary Portland Cement was introduced to the soil at varying contents from 0 to 12% in steps of 3% by weight of the soil sample. Each wet sample of the soil was subjected to the Californian bearing ratio (CBR) and unconfined compressive strength (UCS) tests in determining the optimal soil-cement mix. Results show that CBR and UCS values increased as cement content increased, and a 6% cement content corresponding to a UCS value of 2.88 MPa at 7 days of curing met the specifications of the Overseas Road Note 31 to be used in the construction of road bases. The second treatment involved partially replacing the 6% cement content with BGWA in decreasing steps of 1%. Peak CBR value of 348% at 2% BGWA content (>160% recommended by Kenya road design manual) and UCS value of 2.99 MPa at 7 days of curing were obtained. Thus, BGWA can partially replace cement in stabilizing laterite soil for use in the construction of road bases as per the Overseas Road Note 31 specifications.

Non-OPC binder based on a hybrid material concept for sustainable road base construction towards a low-carbon society

In this study, a non-OPC binder as a cementless material for a road base stabilizer was established based on a hybrid material concept between the pozzolanic and the alkali-activated materials. Solid sodium hydroxide (NaOH) was used as an alkali additive in a dry mixing process to compensate for the early strength in a pozzolanic-based material matrix with its intrinsic property of delaying the strength gain. Effects of varied NaOH concentrations on the fly ash (FA) and hydrated lime (HL) mixes to generate such a non-OPC binder were investigated through the mechanical properties and microstructure observations. The selected non-OPC binders were then mixed with the road base aggregate to evaluate non-OPC-based mixtures' properties against the road base material specifications. The results revealed that the non-OPC binder, the FA–HL mix (FA:HL = 90:10 by weight) with the NaOH content of 3.5% wt by dry aggregate mass, provided the most effective mechanical properties an entire network of gel and needles-sharp cementitious products. Based on the pavement design conducted in this study, the flexible pavement with the non-OPC base layer provided a significantly lower cost and GHG emission than those of the OPC-based material as a benchmark. This non-OPC binder with a hybrid material concept reveals a great potential to be a cleaner product in road construction and rehabilitation for a new era of our low-carbon society.

Ferrochrome slag aggregate: physical-chemical characteristics and potential use in lightly cemented road bases

PurposeMost developing countries simply dump ferrochrome slag as waste which occupies huge areas of useful land. The purpose of this study is to underscore the significance of reusing ferrochrome slag as a sustainable and eco-friendly road aggregate material, with the added benefits of preventing possible environmental pollution and promoting sustainable mining of non-renewable construction materials.Design/methodology/approachPhysical-mechanical characteristics were investigated using various South African National Standards test procedures. Chemical and mineralogical characteristics were evaluated using the X-ray fluorescence and the X-ray diffraction techniques, respectively. The toxicity characteristic leaching procedure test was used to evaluate the slag’s environmental suitability. Using two cement types, cement proportions of 1%, 2% and 3% of the slag aggregate weight mixed with optimum moisture content of the non-treated compacted slag were used to make lightly cemented ferrochrome slag aggregate (LCFSA) composites, subsequently tested for compressive strength.FindingsFerrochrome slag aggregates have excellent physical-mechanical characteristics that conform to international specifications for use in road base construction. The slag can be classified as non-hazardous solid waste. However, in acidic environments, some toxic elements may leach from the slag and pollute the environment. Optimum cement contents of 2.3% (CEM II) and 2.6% (CEM VB) can be mixed with the slag to produce LCFSA for road bases.Originality/valueNo research was found in literature on the use of LCFSA in road bases. This research, therefore, presents new data on mix design and strength properties of LCFSA as well as some physical-chemical characteristics of coarse ferrochrome slag aggregate.

Mechanical And Physical Properties Of Recycled Concrete Aggregates For Road Base Materials

The utilization of recycling recycled concrete aggregates (R-RCA) in road base construction is an option of value-added waste materials. The evaluation of R-RCA appropriateness as a road base material need to study. The use of massive amount of RCA in construction projects has acquired wide notoriety. The use of RCA is due to decrease- of amount natural rock as the original aggregate. The main objectives of this study are to characterize properties of R-RCA as road material, to determine mechanical and physical properties as a road base material, and to identify the R-RCA bearing capacity for road base comparison to natural aggregates. The mechanical and physical properties tests conducted according to standard, including particle size distribution Los Angeles Abrasion, Aggregate Crushing Value, Aggregate Impact Aggregate Density, Flakiness Index, Water Absorption, and California Bearing Ratio (CBR). The results show that the aggregates have an excellent distribution particle size, durability, and shapes as required by specifications R-RCA also produced appropriate CBR and strength for road base applications. These results stipulate exclusive information to utilize R-RCA as aggregates for road base construction. R-RCA can be used as road base construction materials, and its engineering properties transform from waste materials to value-added road base construction. Recycling of RCA not only can diminish the road base construction cost and decrease landfill space needed for disposal, but it engineering properties prone as road base construction, and considered a renewable resource.

Repurposing of stabilised dredged lakebed sediment in road base construction

Repurposing of stabilised dredged lakebed sediment in road base construction

Waste crushed rock stabilised lateritic soil and spent carbide blends as a road base material

ABSTRACT Waste crushed rock (WCR) and spent carbide (SC) composite were used to stabilise lateritic soil (LS) as a road base material. Laboratory investigations were conducted on LS blended with up to 80% WCR by weight of the dry soil to determine the ideal grading and Atterberg limits, which satisfy the Ghana Ministry of Transport (MoT) specification. 40% WCR content was noted as the ideal content. The 40% WCR was then treated with up to 10% SC by weight and subjected to geotechnical tests. The findings revealed notable improvements in the properties of the WCR/LS blend with increasing SC content. The improvement in terms of strength was assessed using California bearing ratio (CBR), which showed ascending values with SC contents. The addition of SC also increased the fines content. Despite the improvement in geotechnical properties of the stabilised LS, comparison with the Ghana MoT standards for road base material indicates that only 10% SC content met the minimum swell specification. However, the grading curves for 0%–7% SC contents substantially fell within the grading envelope. Similarly, all the CBR values passed the minimum specification. Based on the CBR and grading specifications, 40% WCR with 7% SC content is recommended for road base construction.

The Role of Additives in Soil-Cement Subjected to Wetting-Drying Cycles

This study aimed to explore the use of additives in soil–cement mixtures that have undergone a wetting-drying cycle. In total, two types of soil were used, granitic and lateritic, which are widely used in road base construction in the Katingan area, Central Kalimantan, Indonesia. The cement used was the ordinary Portland type I, while the additive utilized was for commercial purposes, and predominantly contained CaCl2. This research was conducted by testing the optimum cement content for each soil to determine the shear strength according to Indonesian standards (i.e., minimum Unconfined Compressive Strength of 2400 kPa). The optimum cement contents of granitic and lateritic soils were deduced to be 5.5% and 5% on a dry weight basis, respectively. The utilization of 0.8% additive resulted in a 0.5% reduction in the optimum cement content of granite-like soil. The results showed that the optimum additive content for granitic soil was higher than that without supplementation, while for lateritic, no changes occurred. The advantage of using supplements, however, was more pronounced in the samples when they had been subjected to wetting–drying cycles. Additionally, at the optimum additive level, the moisture content and soil-cement loss during wetting was always lower than without supplements.

Evaluating the crushing characteristics of recycled construction and demolition waste for use in road bases

With the increasing production of construction and demolition waste (CDW), the use of CDW as a road base has become a sustainable and eco-friendly disposal approach. The aggregate crushing value is an essential index in the construction of road bases and is defined as the mass percentage of fine particles after a confined compression test of recycled CDW. In this study, experiments and numerical simulations were conducted to evaluate the crushing characteristics of the CDW, consisting of three main components, i.e., gravel, brick, and mortar. From the single-particle crushing tests, the gravel was strongest, and the mortar was weakest. Multi-particle confined compression tests showed that the load–displacement curves of the recycled aggregates exhibited an increasing trend. The fluctuations during loading were attributed to the particle breakage. A three-dimensional discrete element method (DEM) with a laser scanning and reconstruction technique was proposed to model irregular-shaped aggregate particles using a cluster of bonded particles. A comparison of the experimental and numerical results showed that the bond breakage ratio linearly increased with the aggregate crushing value, providing a quantitative linkage between the micro-scale numerical model and the macro-scale test. It was found that the volume proportion of the gravel significantly affected the mechanical behavior of the mixed aggregates, and 75% was the critical threshold of the gravel component. As gravel with a volume proportion from zero to 75% was added to the brick or mortar, the aggregate crushing value increased by only 10–15%. In the mixed aggregates with brick and gravel, more of the brick particles were crushed when gravel with a proportion of 50–75% was added due to inconsistent deformation and stress concentration. If the gravel proportion exceeded 75%, the aggregate crushing value was reduced by 30%. Based on the numerical and experimental investigations of the crushing characteristics of the recycled aggregates, a ternary diagram was proposed to design the proportion of the three components in recycled CDW for road bases.

Substantiation of Possible Using Metallurgical Production Waste in the Road Surface and Base Construction and Repair

Substantiation of Possible Using Metallurgical Production Waste in the Road Surface and Base Construction and Repair

Study on Stress Distribution in Soft Ground Consolidated with Deep Cement Mixing Columns under Road Embankment

Soil consolidation using deep mixing method (DMM) is commonly used to protect soft ground in alluvial stratum in deltas such as Mekong Delta. In this study, the finite element method (FEM) using PLAXIS software is adopted to analyze the stress distribution on columns and ground base of the deep cement mixing (DCM) columns system combined with geotextiles in the consolidation of soft ground under road embankment in Tien Giang Province. With this method, the behavior of the DCM columns in soft ground treatment is examined by the distribution of stress and settlement of the DCM columns and soft soil layers. Simultaneously, the settlement of road base construction is monitored. The stress distribution on DCM columns and their settlement are also given from the analysis of FEM. The FEM models simulating the soft ground consolidated with DCM columns combined with geotextile under the road embankment in Tien Giang with the DCM columns of 0.6 m diameter, 11.2 m length and 1.0m center –to- center spacing show the largest settlement of 0.120 m and the stability coefficient of 1.679.

Efficient application of cellulose pulp and paper production wastes to produce sustainable construction materials

The mechanical and physical properties of the composites developed from dregs, grits, and lime mud of the Kraft cellulose and paper production process (55–75%), concrete waste (10–25%) and lime production waste (0–25%), far exceeded the demands of Brazilian standards for bricks, blocks, and road-base construction materials. The study of the developed composites structure by XRF, XRD, SEM, EDS, and LAMMA methods demonstrated that new mainly amorphous formations were responsible for all attained properties. The industrial application of these construction materials would introduce excellent efficiency from an economic and environmental points of view.