Sustainable Pavement Construction Research Articles

Strength and Durability Characteristics of Sustainable Pavement Base Course Stabilized with Cement Bypass Dust and Spent Fluid Catalytic Cracking Catalyst

This study explores the potential of a composite binder comprising cement bypass dust (CBD) and spent fluid catalytic cracking (FCC) catalyst for sustainable pavement base stabilization. Various CBD/FCC ratios (30:70, 50:50, 70:30) and binder contents (4%, 6%, 8%, 10%) were evaluated through laboratory testing. The 50:50 CBD/FCC mixture demonstrated optimal performance, achieving an unconfined compressive strength (UCS) of 15.6 MPa at 28 days with 10% binder content. The mix exhibited improved stiffness (E50 modulus up to 13,922 MPa) and resistance to degradation under wetting–drying cycles, attributable to synergistic cementitious and pozzolanic reactions. Microstructural analysis revealed a denser matrix, validating the enhanced performance. These findings suggest CBD and FCC, as promising materials for sustainable pavement construction, align with circular economy principles.

Fatigue performance evaluation of epoxy-recycling technology utilising 100% reclaimed asphalt pavement (RAP): binders and mixtures

ABSTRACT In this study, a novel epoxy-recycling technology, which produces recycled mixtures using epoxy asphalt as binders, was applied to utilise 100% RAP. However, to date, the fatigue properties of epoxy-recycled asphalt mixtures (ERAM) made of 100% RAP remains unknown. The main objective of this paper is to investigate the fatigue performance of epoxy-recycled binders and mixtures. Thus, the linear amplitude sweep (LAS) tests and repeated semi-circular bending (R-SCB) fatigue tests were conducted to evaluate the fatigue resistance of binders and mixtures, respectively. The binder bond strength (BBS) tests were also performed to investigate their adhesive performance. The results show that the epoxy-recycling technology can recover the fatigue properties of ERAM to similar levels or even far superior to conventional virgin mixtures. Compared to SBS modified asphalt, the bonding strengths of epoxy-recycled binders increase by 92.38%, 110.16%, 133.33%, and 210.76% with increasing epoxy proportions. The fatigue lives between LAS tests for binders and R-SCB tests for mixtures show excellent correlations under power functions, and the fatigue performance enhancement of ERAM can be attributed to greater fatigue resistance of binders and better adhesive properties. The findings will provide evidence-based confidence in epoxy-recycling technology, thereby promoting long-life and sustainable pavement construction.

Investigation on structural and functional behavior of open and dense graded asphalt mixes in mitigating urban floods

Urbanization has led to extensive pavement construction, which, coupled with improper drainage infrastructure, exacerbates urban flooding. Conventional bituminous pavements exacerbate flood risks due to their impermeability, leading to safety hazards and infrastructure damage. To address these challenges, this study investigates the efficacy of Porous Asphalt Concrete (PAC) as a sustainable solution for flood mitigation and pavement durability enhancement. Through laboratory evaluations and flood simulation analyses, the study compares PAC with conventional bituminous mixes in terms of structural, functional, and permeability characteristics. Results indicate that PAC exhibits superior permeability, facilitating effective stormwater management and reducing surface runoff by up to 40%. Furthermore, PAC demonstrates comparable or enhanced performance in Marshall Properties, including stability, flow, and air voids, when compared to conventional mixes. The incorporation of Induction Sensitive Fibers (ISF) enhances pavement durability and moisture resistance, leading to improved tensile strength and reduced abrasion. Binder performance analysis reveals that CRMB-55 exhibits superior stability and durability, making it a promising option for sustainable pavement construction. Flood simulation analyses using QSWAT software demonstrate the effectiveness of PAC in mitigating urban flooding, with notable reductions in surface runoff and discharge. Overall, this research underscores the potential of PAC as a viable solution for sustainable pavement construction, offering both flood mitigation benefits and enhanced pavement durability in urban environments.Graphical

WITHDRAWN: An Experimental Investigation on Utilising RAP and PCD Waste in Bituminous Mixes for Developing Sustainable Pavement Construction Practices

WITHDRAWN: An Experimental Investigation on Utilising RAP and PCD Waste in Bituminous Mixes for Developing Sustainable Pavement Construction Practices

Comprehensive Review on Utilization of Construction Demolished Waste and Crumb Rubber for Sustainable Pavement Construction

Comprehensive Review on Utilization of Construction Demolished Waste and Crumb Rubber for Sustainable Pavement Construction

Development of sustainable interlocking concrete paving blocks using bamboo leaf ash and metakaolin

Eco-friendly interlocking concrete pavement block was developed using the admixture of bamboo leaf ash and metakaolin. This was done to develop an eco-friendly interlocking paving block for sustainable pavement construction. Bamboo leaf ash and metakaolin were added as a supplementary cementitious material. The supplementary cementitious material (bamboo leaf ash and metakaolin) were admixed and added at 0, 5, 10, 15, 20, 25 and 30 % replacement of cement. The workability of the fresh concrete (slump) at the varied percentage additions, and the mechanical properties of the concrete at 7, 14, 28, and 56 days of curing were assessed, including their microstructural characteristics. The outcome of the research showed that increasing the percentage of (bamboo leaf ash + metakaolin) reduces the workability of the concrete. With a 20 % addition of this cementitious material, the developed fresh concrete became unworkable. In addition, replacing up to 10 % of the concrete in the pavement with bamboo leaf ash and metakaolin increased the mechanical strength of the concrete by 28.7 %. At 30 % a percentage increase of 3.6 % was recorded. However, the strength at 5 % was still adequate for pavement construction with a 13.62 % increase in mechanical strength. The compressive strength at 5 % and 10 % addition of the supplementary cementitious material at maturity met the criteria for constructing a semi-rigid pavement, using IRC standards. The microstructural assessment showed that the number of pores in the mature concrete samples decreased at 10 % addition of bamboo leaf ash and metakaolin. The research data provides construction workers, researchers, and highway engineers with vital information regarding the viability of these sustainable materials for pavement improvement.

Sustainable Pavement Construction in Sensitive Environments: Low-Energy Asphalt with Local Waste Materials and Geomaterials

Low-energy asphalt techniques, such as warm mix asphalt (WMA), combined with the rational consumption of geomaterials and waste recycling would promote more sustainable and energy-efficient asphalt pavements. In volcanic environments, a significant proportion of aggregate production is discarded due to its extreme porosity, and used tires generate a main environmental issue as well. While recycled rubber powder from tire waste can enhance the mechanical behavior of asphalt, it also raises its viscosity. Therefore, joining rubberized asphalt containing local waste geomaterials with WMA technologies is crucial to reduce the manufacturing temperatures and emissions and to produce more eco-efficient pavements. For this purpose, the most relevant technological characteristics of rubberized warm mix asphalt with residual aggregates from highly vesiculated volcanic rocks are tested in the laboratory and contrasted with conventional mixtures. The outcomes demonstrate not only the feasibility of the production of such mixtures in line with the current specifications, but also show a significant improvement in the resistance to moisture and to plastic deformations, and an improvement in the stiffness modulus. The eco-efficiency indicators conclude that the energy consumption and emissions are reduced by 9%, enabling the reuse of waste materials by more than 95%.

Assessing recycled asphalt pavement: Impact of waste cooking oil and waste engine oil as rejuvenators on mechanical properties

Sustainable pavement construction is an extensively researched subject within the field of pavement engineering. Due to its environmental and commercial advantages, the construction of pavements utilizing recycled asphalt pavement (RAP) is progressively gaining popularity worldwide. Owing to the aging process, binder extracted from RAP is inherently harder than virgin binder and requires rejuvenation for application in high RAP blends. This paper investigates the performance characteristics of Waste Cooking Oil (WCO) and Waste Engine Oil (WEO) as rejuvenators in RAP-incorporated asphalt mixtures to assess their suitability for pavement use. The optimal rejuvenator content is determined based on the performance of physical properties. The study indicates that asphalt mixes rejuvenated with Waste Cooking Oil (WCO) demonstrate higher Marshall Stability values compared to mixes rejuvenated with Waste Engine Oil (WEO) at both 30% and 60% Recycled Asphalt Pavement (RAP) levels. Additionally, mixes incorporating WCO exhibit increased flow values. Furthermore, WCO outperforms WEO in Tensile Strength Ratio (TSR) at 30% RAP, with a slight decrease at 60% RAP. Results from Marshall and Indirect Tensile Strength (ITS) tests suggest that both WEO and WCO are effective rejuvenators, playing a critical role in aligning the properties of RAP-inclusive asphalt mixes with those of virgin mixes.

Experimental study on the utilization of construction and demolition waste of recycled aggregate with GGBS and I-Crete in pavement quality concrete

This study investigates the mechanical properties of M40 concrete in Pavement Quality Concrete (PQC) by incorporating Recycled Aggregates (RA) from construction, demolition waste and industrial wastes, such as GGBS and I-Crete, for sustainable pavement construction. The research explores varying proportions of RA (25% to 100% by weight in 25% intervals). Results show concrete mechanical strength decreases with higher RA proportions but all mixes still meet target strength criteria (compressive, flexural, split tensile) at 7, 28, and 90 days of curing. Further testing on 100% RA (MRCA-100) with GGBS admixture from 5% to 35% in 5% increments found strength improves significantly up to 10% GGBS replacement by cement weight, with subsequent decreases at higher percentages Initially. Then introducing the mineral additive, I-Crete at 2% by weight of cement in 15% to 35% GGBS range results in notable strength enhancement, peaking at 25% GGBS replacement. Ultrasonic pulse velocity (UPV) and water absorption tests showed similar trends in 28-day strength across all mixes. Increased strength from better bonding was observed, with Scanning Electron Microscopy (SEM) showing enhanced hydration and bonding due to mineral admixture and additive. These findings underscore the efficacy of such additives in enhancing the mechanical strength of sustainable PQC.

Short-term and long-term aging effect of the rejuvenation on RAP binder and mixes for sustainable pavement construction

• Physical and rheological properties of rejuvenated RAP and virgin binder compared. • Determination of optimum dosage range of the rejuvenator. • Performance evaluation rejuvenated RAP mixes. This investigation analyzes the usefulness of Mahua oil (M-oil) in reclaimed asphalt pavement (RAP) binder which simulates the short-term and long-term aging behavior of asphalt. As the inclusion of a higher amount of the RAP in the bituminous mix is susceptible to fatigue and thermal cracking, the use of a rejuvenator is a suitable option that can reinstitute the properties of the virgin binder. Different percentages of M-oil such as 1%, 2%, 3%, 4%, 5%, and 6% added to the short-term and long-term aged binder. Blended rejuvenated binders were evaluated through various physical properties. It was noticed that the inclusion of a rejuvenator increases the penetration, ductility, and flash point and reduces the softening point, and viscosity. Rheological properties conclude that rejuvenating short-term and long-term aged binder is feasible and can be considered an effective way to recycle the RAP binder. Further, rejuvenated (5% and 6% M-oil by weight of aged binder which is the optimum dosage) mixes were prepared with RAP mixture for short-term and long-term aging conditions to study the mechanical properties, i.e., moisture sensitivity and rutting. Finally, it was concluded that 5% M-oil successfully rejuvenated the RAP mixes in long-term aging conditions.

Sustainable Pavement Construction: A Comprehensive Review on the Use of Recycled Materials and their Impact on Performance

Sustainable Pavement Construction: A Comprehensive Review on the Use of Recycled Materials and their Impact on Performance

Mechanical Characteristics and Durability of HMA Made of Recycled Aggregates

The application of recycled aggregates in the asphalt industry has been investigated in recent decades. However, low percentages of these materials have practically been used in asphalt mixtures because of the limitations set by the relevant specifications due to their performance uncertainties. This research investigates the feasibility of increasing the percentage of recycled aggregates to 100% in hot mix asphalt (HMA). Recycled concrete aggregate (RCA), recycled glass (RG), and reclaimed asphalt pavement (RAP) were used to develop HMAs suitable for roads with light to medium traffic. First, potential mix designs were proposed using an innovative approach considering the industry’s needs. Next, the volumetric properties, tensile strength, moisture sensitivity and resilient modulus response of the mixtures under different temperature conditions were determined and compared. In general, the proposed recycled material HMA exhibited superior mechanical and resilient modulus performances, i.e., 45 to 145% increase in stiffness, and up to 99% higher in Marshall stability. Furthermore, higher tensile strength ratios of the recycled material mixtures indicated a greater resistance to water damage, and hence greater durability. The findings of this research provide evidence-based insights into the increased proportion of recycled materials in the construction of asphalt pavements, thereby promoting sustainable pavement construction materials.

Scheffe's Simplex Optimization of Flexural Strength of Quarry Dust and Sawdust Ash Pervious Concrete for Sustainable Pavement Construction.

Pervious concrete provides a tailored surface course with high permeability properties which permit the easy flow of water through a larger interconnected porous structure to prevent flooding hazards. This paper reports the modeling of the flexural properties of quarry dust (QD) and sawdust ash (SDA) blended green pervious concrete for sustainable road pavement construction using Scheffe's (5,2) optimization approach. The simplex mixture design method was adapted to formulate the mixture proportion to eliminate the set-backs encountered in empirical or trials and the error design approach, which consume more time and resources to design with experimental runs required to evaluate the response function. For the laboratory evaluation exercise, a maximum flexural strength of 3.703 N/mm2 was obtained with a mix proportion of 0.435:0.95:0.1:1.55:0.05 for water, cement, QD, coarse aggregate and SDA, respectively. Moreover, the minimal flexural strength response of 2.504 N/mm2 was obtained with a mix ratio of 0.6:0.75:0.3:4.1:0.25 for water, cement, QD, coarse aggregate and SDA, respectively. The test of the appropriateness of the developed model was statistically verified using the Student' t-test and an analysis of variance (ANOVA), and was confirmed to be acceptable based on computational outcomes at the 95% confidence interval. Furthermore, the scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) were used to evaluate the morphological and mineralogical behavior of green prior concrete samples with various additive mixture compositions. The addition of QD and SDA, on the other hand, aided the creation of porous microstructures in the concrete matrix due to fabric changes in the concrete mixture, potentially aided by the formation of cementitious compounds such as calcium aluminate hydrate and calcium silicate hydrate.

The utilization of palm kernel shells and waste plastics in asphaltic mix for sustainable pavement construction

Natural aggregates are being depleted due to the high demand for road and building construction and need to be replaced with alternative materials. This study investigated the potential of using Palm kernel shells (PaKS) as a partial replacement for natural aggregates (NA) and waste plastics (WP) as a binder. The physical and volumetric properties of the different asphaltic mixes (AM) were assessed using the Marshall Method. The bitumen content of the mix design samples was varied from 4.0 % to 7.5 % of the total weight of aggregates utilized. According to the Marshall parameters, at 5.5 % bitumen content, the maximum Marshall Stability value of the different mix designs increased from 9.8 kN to 12.1 kN and the flow value increased from 3.0 mm to 3.7 mm. The experimental results based on the optimum bitumen content determined by the Marshall method demonstrate that PaKS and WP can be utilized to modify AM. However, additional tests will be needed to evaluate the use of this composition in road construction.

Evaluation of Pavement Roughness by the International Roughness Index for Sustainable Pavement Construction in New Taipei City

Good road quality is an indicator of urban progress. In August 1998, the New Taipei City government implemented the “Road Leveling Project” on roads within its jurisdiction to improve the quality of public transportation. This paper aimed to analyze the International Roughness Index (IRI) of 152 asphalt concrete pavement sections in New Taipei City before and after road leveling. An intelligent pavement inspection vehicle that met the requirements of E 950 Class I was used to detect the IRI values of the road sections before and after maintenance. The statistical analysis showed that the implementation of the Road Leveling Project had a significant effect on improving the road roughness of roads under its jurisdiction. Moreover, it became possible to arrange a budget for roads with IRI values above a threshold or to estimate the budget needed to improve roads with an IRI higher than a certain value.

Microstructural behaviour of quarry fines stabilised with fly ash-based binder

Stabilised quarry fines have been explored as sustainable pavement construction materials. This study investigates the viability of such materials for applications in pavement structures, contributing to current knowledge on mechanical performance from the perspective of mineralogy, microstructure, and chemical composition of the material. This study uses fly ash-based material as stabiliser, promoting circular economy considering the availability of fly ash worldwide by 2030. Laboratory tests were performed including unconfined compressive strength (UCS), mineralogical analysis, and microstructure investigations by scanning electronic microscope (SEM) and energy dispersive X-ray spectroscopy (EDX). Using different binders, Calcium was found to be the element with most variability in mass, and the UCS increased proportionally as the ratio of CaO/SiO2 or CaO/(SiO2+Al2O2) increased. As curing time accumulates to 28 days, more cementitious reaction products were generated and observed, and the void to solid ratio reduced in some samples, possibly leading to improvements in the UCS.

Investigation of the Reusability of a Polyurethane-Bound Noise-Absorbing Pavement in Terms of Reclaimed Asphalt Pavement.

A key aspect of sustainable pavement construction is the use of environmentally-friendly designed pavement materials. These materials are characterized by the fact that they are renewable raw materials, require a low amount of energy during production and in the best case, are made from a high proportion of recyclable materials in order to reduce waste. A number of recent studies have demonstrated the recyclability of waste materials that can be very well utilized in road construction. This study describes the recycling of a new and innovative topcoat system that already contains recycled materials. However, the focus is on guaranteeing the mechanical performance of the innovative absorption layer where different portions of used material are added. Therefore, low-temperature behaviour, durability, fatigue and noise absorption are investigated in detail and it is concluded that their function is preserved. In order to investigate these characteristics, the impedance measuring tube, the uniaxial cyclic compression test (UCCT), the three point bending test (3PB), the uniaxial tension stress test (UTST) and the thermal stress restrained specimen test (TSRST) are used. However, the examined absorption material can be reused to build innovative roads.

Tensile Strength And Moisture Sensitivity of Sulfur Waste in Asphalt Mixtures As An Eco-friendly Filler

Sulfur waste (SW) materials continue to accumulate in Iraq, posing an expensive disposal and gas emission problem. Utilizing SW as a mineral filler is a cost-effective way to reduce the amount of common filler (calcium carbonate; CaCO3) used and hazardous gas emissions. SW was used to gradually replace a component of the asphalt binder in hot asphalt mixes. The purpose of this research is to explore the use of SW as a mineral filler in the construction of sustainable pavements. Three sulfur waste asphalt concrete (SWAC) mixes with asphalt binder penetration grades of 40–50 were created and compared to the study's CaCO3-asphalt concrete (AC) reference mix. Different percentages of SW (4%, 5%, and 6%) by weight and one AC blend contained a CaCO3 content of 5% (by weight) were prepared. The Marshall stability, Marshall quotient, tensile strength ratio at 25 and 60°C, tensile strength modulus at 25 and 60°C, tensile strength ratio, and tensile stiffness modulus of AC and SWAC mixtures were all determined. Tensile strength, tensile stiffness modulus, tensile strength ratio, and resilience modulus are all decreased in SWAC mixtures. Despite the lower SWAC percentage, tensile strength ratios remain higher than the required minimum of 85 percent when 40-50 penetration grade asphalt is used. Additionally, SWAC combinations have higher flow values, indicating a greater strain capacity to rupture. As long as the proper binder content is maintained, all SWAC combinations meet the ASTM standards for 8kN stability, 2-4mm flow, 5% air voids, and 14% VMA. This study found that SW can be reused and used as a mineral filler in pavement applications at a rate of 4–5% by aggregate weight

Laboratory Investigation of Microwave Healing Characteristic of Hot Mix Asphalt Incorporating Steel Slag and Fly Ash

Abstract: This research aims to analyze the usage of fly ash (FA) as filler and Steel slag as coarse aggregate in hot mix asphalt concrete to monitor its healing characteristic under microwave heat. Both fly ash and steel slag are the industrial by-products. Using Marshall, Hot mix asphalt (HMA) mixtures were prepared for control and three different modified specimens having 10%, 20% and 30% steel slag as coarse aggregate, and 75% optimum fly ash content (OFC) as filler. Then thermal distribution and optimum healing time of test specimens were recorded using infrared thermometer. A three-point bending (TPB) tests were applied to the samples before and after the microwave healing procedures. Test results demonstrated that adding steel slag and fly ash in asphalt concrete mixtures increases the heating rates and improve the healing performance of hot mix asphalt using microwave heat. The replacement of natural coarse aggregate by 30% steel aggregate is extremely promising since it has not only improved healing results but also enhance the load-displacement relationship of the HMA mixtures with more ductile behavior. Overall, the use of steel slag and fly ash in hot mix asphalt is a significant option that helps to the sustainable pavement construction as it improves healing and cracking resistance. Keywords: Fly ash, Steel slag, Hot mix asphalt, Microwave heating, Three-point Bending

An Easy Way To Determine The Flexural Quality Of Asphalt Is Using ASTM D113 – 07 and SNI 2432:2011

Asphalt is a material that has non-volatile properties and softens gradually when heated and functions as a binder for aggregates and as a surface covering material to make it impermeable to water. However, asphalt also has a weakness. Namely, it is easy to crack and be damaged when vehicles pass through the main road. To overcome cracked and worn roads, it is necessary to test the ductility of asphalt so that the road becomes flexible/plastic. This ductility test is very important because it greatly affects the pavement layer; Therefore, a ductility test is needed to determine the level of plasticity of an asphalt. The asphalt ductility test method refers to the specifications of ASTM D113 – 07 and SNI 2432:2011 with 3 samples of test objects and a test instrument called a ductilometer of type TAS – 250. Based on the ductility test, the asphalt ductility reaches an average elongation of 117.33 cm; This value indicates that the plasticity level of the asphalt has met the specifications and can be used in sustainable pavement construction layers because it has good plasticity.