Stone Matrix Asphalt Research Articles

The The Effect of Geothermal Waste as Filler Substitution on Stone Matrix Asphalt (SMA) Characteristics

The The Effect of Geothermal Waste as Filler Substitution on Stone Matrix Asphalt (SMA) Characteristics

Optimizing epoxy asphalt tack coat formulations for improved adhesion and working performance of ultrathin wearing course

Insufficient adhesion between ultrathin wearing courses (UTWCs) and substrate layers can result in pavement distress. Epoxy asphalt exhibits potential as a tack coat due to its high bonding strength and thermal stability. However, its rapid curing may pose challenges to construction schedules. This study aimed to optimize the formulations of epoxy asphalt tack coats (EATCs) to enhance the interfacial adhesion and working performance of UTWCs. The adhesion of EATCs was evaluated through rotational viscosity and tensile tests. Design parameters were optimized using analysis of variance and microscopic tests. Road performance was assessed via interlayer shear and tensile testing on three pavement structures. The results indicated that the curing agent strongly influenced the properties and curing kinetics of EATCs. Formulations containing complex polysebacic polyanhydride (CPSPA-EA) exhibited superior bonding while meeting construction schedules. Microscopic analysis of CPSPA-EA revealed a stable crosslinked network formed at 30% binder dosage. The amount of spraying significantly impacted the adhesion in UTWC structures. The optimal spraying amounts were 0.60 kg/m2 for asphalt concrete (AC-13), 0.55 kg/m2 for stone matrix asphalt (SMA-13), and 0.40 kg/m2 for cement concrete substrate layers. These findings presented an optimization framework for designing EATCs to enhance UTWCs working and long-term performance through balanced tack formulations and application parameters.

Recycling steel slag as aggregate in developing an ultra-thin friction course with high comprehensive road performance

The demand for skid-resistant and wear-resistant alternative aggregates in the preparation of ultra-thin friction course (UTFC) asphalt mixtures is a key direction for achieving high durability and low-carbon development in pavement maintenance. As a typical industrial waste, steel slag with high alkalinity and strong adhesion can facilitate the mechanical property of asphalt mixtures. However, few researches focused on the impact of steel slag on the comprehensive road performance of UTFC mixtures. Hence, the issue merits systematic exploration. In this study, the chemical components, microstructure and morphological characteristics of three steel slags (GXSS, HBSS and IMSS) obtained from different sources were surveyed. Then the stone matrix asphalt (SMA)-5 and open-grade friction courses (OGFC)-5 mixtures with different steel slags were fabricated. And their comprehensive road performances were quantitatively explored via the improved radar chart. The results indicate that steel slag with approximately 40 % Ca content, about 20 % Fe content, irregular shapes and tiny pores endows its wear resistance and strong adhesion. IMSS demonstrates the largest average angularity and form 2D values of 3850 and 7.28, respectively, representing its significant crowding function and interlocking structure. Incorporating steel slag remarkably reinforces the rutting resistance, skid resistance and anti-interlayer shear performance of UTFC. While the effect of water stability and crack resistance of UTFC depend on the category of steel slag. All three steel slags manifest the improvement function on the comprehensive assessment indexes (CAI) of OGFC-UTFC. IMSS-OGFC reveals the optimal comprehensive road performance, achieving the highest CAI of 0.9909. It is inferred that steel slag is more suitable for OGFC-UTFC than SMA-UTFC due to its relatively high CAI and consistent performance regardless of the steel slag type.

Analysis of the frictional performance development of recycled stone matrix asphalt (SMA) mixtures

Analysis of the frictional performance development of recycled stone matrix asphalt (SMA) mixtures

An Experimental Investigation into the Effect of Ceramic Fiber on the Fatigue Cracking of Stone Matrix Asphalt

An Experimental Investigation into the Effect of Ceramic Fiber on the Fatigue Cracking of Stone Matrix Asphalt

Carbon emission calculation and uncertainty analysis of asphalt concrete during the production stage

Asphalt concrete is the main material consumed by road engineering. At present, there is no uniform standard for determining the carbon emissions of different types of asphalt concrete, and the calculation process is uncertain. In this study, a carbon emission calculation method that combines theory with practice is proposed. First, a theoretical carbon emission model based on the heat balance equation and an actual carbon emission model based on actual energy data are established, and the key links in the carbon emissions of asphalt concrete are determined. Second, the carbon emission correction factors of five different types of asphalt concrete are obtained to estimate the actual carbon emissions more accurately. Finally, the uncertainty of the parameters is evaluated and characterized via the DQI-Monte Carlo simulation method. The results show that the carbon emissions from large to small are modified asphalt concrete (MAC) > ordinary asphalt concrete (AC) > stone matrix asphalt (SMA) > recycled asphalt concrete (ZAC) > warm mix asphalt concrete (WAC). The aggregate heating stage is the key link in the carbon emission of asphalt concrete. Controlling the aggregate heating temperature and moisture content is the most direct and efficient energy savings and emission reduction measure.

Modeling and design optimization of the performance of stone matrix asphalt mixtures containing low-density polyethylene and waste engine oil using the response surface methodology

In recent years, the use of waste plastic materials such as low-density polyethylene (LDPE) to modify asphalt binders and enhance mixture performance has garnered significant attention. One major concern with using such materials is the higher production temperature required, which necessitates the use of a bitumen extender agent, such as waste engine oil (WEO), to reduce the viscosity and mixing temperature. Therefore, using these stabilizing additives can reduce the consumption of virgin binder, especially for Stone Matrix Asphalt (SMA) mixtures, which require higher asphalt content. This study aimed to optimize the design of SMA modified by LDPE and WEO to minimize the optimum asphalt content (OAC) and mixing temperature while maximizing SMA performance. To achieve this, Response Surface Methodology (RSM) was utilized to develop the necessary models for optimizing design and predicting performance. The selected independent variables (factors) for the design include LDPE content, WEO content, OAC, and mixing temperature. Meanwhile, the responses (dependent variables) consist of Marshall stability, rut depth, tensile strength ratio, and resilient modulus, which were used to determine the best mix design. The findings demonstrated that the suggested models for the output variables can predict performance with a higher level of confidence. The Analysis of variance (ANOVA) demonstrated that predictive models were significant and well-fitted, with a coefficient of determination (R2) of higher than 0.80, an adequate precision value of greater than 4, and a low p-value (less than 0.05). The error percentage between the RSM-predicted and actual values was less than 5 %, indicating that RSM-established models can accurately and efficiently predict the SMA performance. The best mix design of the SMA mixture modified by LDPE and WEO was found to be 10 % LDPE, 3.91 % WEO, 5.92 % OAC, and mixing temperature of 152.24°C with a combined desirability of 82.8 %.

Spectral noise reduction of double-layer porous asphalt: From laboratory to field

The double-layer porous asphalt (DLPA) pavement is a practical way to mitigate traffic noise from the source. However, there hasn't been much research done on the spectral noise characteristics of the car/truck on this type of pavement with different surface conditions yet. The objective of this paper was to reveal these noise characteristics and the behaviors of the DLPA pavement by laboratory tests and field measurements. First, measurements were made of the road performance of different porous asphalt (PA) mixtures and DLPA structures. Then, a vector impedance measurement system was utilized to evaluate the effects of porosity, aggregate size, and thickness on the sound absorption coefficient (SAC) of the DLPA slabs. Third, a sound meter was used to record the noise levels outside/inside the car/truck on the roads with three surface conditions for the DLPA (PA-10+PA-20) and stone matrix asphalt (SMA) test section, which were paved on an elevated urban road. Finally, an analysis was done on the overall and spectral noise characteristics. The results demonstrated good road performance of these PA mixtures and DLPA structures. Relatively fine and coarse aggregates in the upper and lower layers, respectively, enhanced the sound absorption. But an increase in porosity beyond 20 % and a slight variation in thickness did not considerably improve the sound absorption. Compared to SMA pavement, the overall noises levels of the DLPA pavement were 4–8 dBA lower on the “dry” surface and 6 dBA lower on the “wet” surface. The DLPA pavement exhibited a noise reduction at the full frequency band, which attributed to the pore structure and the relatively fine aggregate used. The interior sound energy always concentrated on the low-frequency band. However, the exterior sound energy on the “dry” and “wet” road surfaces tended to the low-frequency and high-frequency bands, respectively. These findings would shed light on the spectral noise characteristics of the DLPA pavement and provide a new knowledge about the behaviors of the lower layer and upper layer in relation to noise reduction and road performance.

Characteristics of the Warm Mix Asphalt with Emulsion as Additives in Engineering

The technology known as Warm Mix Asphalt (WMA), just unveiled in Europe, is becoming increasingly popular across the globe. By lowering the bitumen binder's viscosity, this cuttingedge technique makes asphalt mixtures more workable at lower temperatures between 30-40°C needed to generate conventional Hot Mix Asphalt (HMA). Reduced pollutants, energy savings, and a less offensive smell result from the lower mixing and compaction temperatures. More studies are necessary to evaluate its long-term performance. Based on MORTH requirements, this study examines the efficacy of bitumen emulsion as an addition in WMA samples of Stone Matrix Asphalt (SMA) and Dense Bituminous Macadam (DBM) mixtures. The combinations' binder contents varied from 4% to 7% of the aggregate weight. For the DBM and SMA mixes, cement and stone dust were utilized as fillers, and VG 30-grade bitumen was employed as the binder. For SMA and DBM mixtures, the ideal binder contents were determined to be 6.92% and 6.32%, respectively.

Performance assessment of polyester fiber modified stone matrix asphalt mixtures with statistical analysis

Performance assessment of polyester fiber modified stone matrix asphalt mixtures with statistical analysis

Experimental simulation evaluation and control measures of paving segregation for the stone matrix asphalt mixtures

The aggregate segregation for asphalt mixtures, characterized by non-uniform particle distribution, significantly undermines the quality and performance of pavements. This investigation aims to explore and reveal the mechanisms underlying segregation, including raw material properties and construction procedures. Novel evaluation methods, predictive metrics, and control measures were introduced using the developed apparatus. The results indicate that physical properties, particle morphology, and gradation are fundamental factors driving segregation. Spatial hindrance, interfacial friction, collision, and self-organization collectively coordinate particle spatial migration and distribution. Excessive coarse particles induce interstitial displacement, while that of fine particles trigger third-body lubrication. The lubricating-bonding factor η was proposed to characterize asphalt regulation. Segregation prediction based on composite angularity facilitates informed raw material selection. In addition, measures to improve paving quality and efficiency during loading, unloading, and auger mixing were proposed. This research contributes to the understanding of segregation mechanisms, enabling early prevention and effective management strategies.

Using Waste Cigarette Butt Fibers as Asphalt Binder Stabilizer in Stone Matrix Asphalt: Mechanical and Environmental Characterization

Using Waste Cigarette Butt Fibers as Asphalt Binder Stabilizer in Stone Matrix Asphalt: Mechanical and Environmental Characterization

Comparative evaluation of open graded friction course and stone matrix asphalt mixtures with modified binders and warm mix asphalt

Comparative evaluation of open graded friction course and stone matrix asphalt mixtures with modified binders and warm mix asphalt

Effects of warm-mix additives, anti stripping agent, and graphene nanoplatelet on the cracking resistance, moisture susceptibility, and cost effectiveness of stone mastic asphalt

Moisture and cracking damages are two of the most common asphalt pavement distresses in the United States. The use of stone matrix asphalt mixture has gained popularity due to its high durability, resistance to permanent deformation and cracking, and reduced noise pollution. Warm-mix additives and nanomaterials have also gained significant interest as promising asphalt binder additives. In order to achieve enhanced resistance to moisture and cracking in extremely wet regions, this study investigated the effects of three warm-mix additives, an anti-stripping agent, and one nanomaterial (graphene nanoplatelet) on the cracking and moisture resistance performance of stone matrix asphalt. Fourier transform infrared spectroscopy and sessile drop tests were used to evaluate the functional groups and moisture susceptibility of the modified asphalt binder blends, respectively. The indirect tensile asphalt cracking test and the modified Lottman tests were used to evaluate the mixtures' resistance to cracking and stripping damage. A cost-effectiveness analysis as well as a two-dimensional performance interaction diagram were employed based on the laboratory performance of the mixtures. Results indicated that the graphene nanoplatelet modification of the asphalt binder had the highest wettability potential, adhesion, and debonding properties, as well as moisture resistance potential compared to other additives. In terms of mixture cracking performance, both the graphene nanoplatelet and a chemical warm-mix asphalt significantly improved the mix cracking performance by 34.1 and 30.0 %, respectively, compared to the control mix. However, the graphene nanoplatelet modification had a tensile strength ratio of 0.76, which is below the acceptance threshold of 0.80 set by AASHTO T 283 for moisture damage resistance of asphalt mixture. Overall, all mixtures with warm-mix additives showed adequate cracking and stripping damage resistance performance and are expected to be cost-effective.

Advancing Field Aging Simulation Methods for Cantabro Abrasion Loss Testing

Over the past several years, the asphalt industry has progressively increased efforts to evaluate mixtures after laboratory conditioning for the purpose of simulating field aging, and has also increased reliance on mixture testing. AASHTO T 401-22 describes Cantabro Mass Loss testing and has an appendix of field aging simulation protocols that can be used to estimate field aging by making use of compacted specimens. T 401-22 is one of the few methods to contain both a field aging simulation protocol and a mixture property index test. This paper uses roughly 1,000 tested specimens from forty-nine mixes (mostly dense-graded asphalt with minor amounts of stone-matrix asphalt) evaluated for up to four years of field aging in a hot and non-freeze climate alongside twenty-five different laboratory conditioning protocols. This paper’s objective is to provide information to improve T 401-22 by way of recommendations to update the appendix of conditioning protocols with more comprehensive assessments of their effectiveness in simulating field aging in a hot, non-freeze climate. The overarching recommendation of this work culminates with four protocols. Two of these protocols use only oven conditioning, whereas the remaining two protocols use a combination of stages exposing specimens to oxidation in ovens, moisture effects in hot water baths, and freeze–thaw cycling. The time required to administer the recommended protocols varies from approximately 6 to 28 days and they simulate between 1 and 5 years of field aging depending on the protocol selected.

Experimental Research on Gradation Range and Performance of SMAC13.

Stone matrix asphalt and asphalt concrete mixture with 13.2 mm nominal maximum aggregate size (named SMA13 and AC13, respectively) are widely used in the surface course of asphalt pavement in China. Generally, the pavement performance of SMA13 is superior to that of AC13, while the cost of the former is significantly higher than that of the latter. The objective of this paper was to develop a new hot mix asphalt (named SMAC13) whose performance and cost are between SMA13 and AC13. A boundary sieve size (BSS) of 2.36 mm was selected between fine and coarse aggregates. Based on the union set of aggregate gradation ranges of SMA13 and AC13, the family of gradation curves in the forms of S shapes were designed in terms of the BSS passing rate. According to the evaluation of the skeleton interlock of coarse aggregate of the gradation curve family, the aggregate gradation range of SMAC13 was determined. Also, the performance of three kinds of asphalt mixtures were compared through laboratory tests. The results indicated that SMA13 shows the best rutting resistance, followed by SMAC13 then AC13, while in terms of low-temperature performance in resistance to cracking, the sequence is SMAC13, AC13, and SMA13. The sequence of water stability is AC13, SMAC13, and SMA13. Furthermore, the cost of SMAC13 is 25% less than that of SMA13. Therefore, SMAC13 can be used as an alternative for the surface course of asphalt pavement in terms of performance and cost.

Optimization of Fracture and Moisture Damage Resistance of Stone Matrix Asphalt Mixtures Containing Crumb Rubber-Modified Binder with the Fracture Mechanics Approach

Optimization of Fracture and Moisture Damage Resistance of Stone Matrix Asphalt Mixtures Containing Crumb Rubber-Modified Binder with the Fracture Mechanics Approach

Analysis of Steel Slag Sand – An Eco Friendly Fine Aggregate for Construction

Industrial waste slag is a major issue concerning the environmentalists today. The steel making industry produces a large amount of byproduct which is termed as Slag. Slag is produced during the steel-making operations that utilize Electric Arc Furnaces (EAF) and operate by smelting iron ore in the Basic Oxygen Furnace (BOF). Steel slag finds numerous uses in the construction industry e.g in the applications involving hot mixture asphalt, in Stone Matrix Asphalt (SMA), berms and embankments constructions, main ingredient in manufacturing of Portland cement, as fine and coarse aggregates, to name a few. But steel slag has a negative impact on the environment when disposed of. In that case a wide variety of use of steel slag becomes relevant. Steel Slag is a perfect candidate to replace the coarse and fine aggregates in the traditional concrete used in the construction industry. Most of the volume of concrete is aggregate. Steel Slag can be used as replacement to these aggregates in a more prominent way. In this research study, we will be making steel slag as substitution for raw fine aggregate. Fine aggregate would be replaced by these wastes in different proportions (20%, 40%, & 60 %) by weight of fine aggregate. The aim of this study is to investigate the compressive strength, split tensile strength and Material properties of concrete with partial replacement for fine aggregate. We will be performing pull off test on the applications of this modified concrete and checking the results for strength and durability.

Evaluation of the influence of warm additives modified by Vestenamer polymer on the performance of stone matrix asphalt containing crumb rubber

This study aimed to evaluate the impact of Vestenamer polymer and warm mix asphalt (WMA) additives (Zycotherm, Sasobit, and PAWMA) on the resilient modulus and rutting behavior of crumb rubber (CR)-modified stone matrix asphalt (SMA) using resilient modulus and wheel tracking tests. The resilient modulus test illustrated that CR-modified SMA mixtures containing WMA had a greater resilient modulus than the control mixture. Also, Sasobit had the highest effect on enhancing the resilient modulus. The wheel tracking test revealed that in each percentage of CR, WMA additives decreased the rutting depth of SMA mixtures, and Sasobit represented the lowest rutting depth among WMA additives. By adding 8, 12, and 16% CR, the rutting depth of SMA was reduced by 30.57%, 50.03%, and 64.76%, respectively, compared to the control sample. Therefore, the application of CR-modified SMA mixtures containing Sasobit can have a considerable impact on improving the rutting resistance of asphalt pavement.

Application of waste rice straw as fibre or filler in asphalt mixtures: materials characterisation and performance evaluation

ABSTRACT This study investigated the application of agricultural waste rice straw as fibre or filler in asphalt mixtures. Initially, the physical, chemical, mineralogical and morphological characterisation of rice straw products were analysed. Subsequently, the performance of stone matrix asphalt (SMA) mixtures containing rice straw fibre was evaluated in terms of rutting, crack resistance and moisture susceptibility, compared to cellulose fibre. Additionally, the properties of asphalt concrete (AC) mixtures incorporating rice straw filler to replace conventional mineral filler partially were examined. The findings revealed that rice straw products exhibited similar characteristics to cellulose fibre or mineral filler, indicating their suitability for use in asphalt mixtures. The appropriate addition of rice straw fibre or filler demonstrated enhancement in the high-temperature performance, low-temperature crack resistance and moisture stability of asphalt mixtures. Through experimental tests, the optimum content of rice straw fibre in SMA-13 mixtures was determined to be 0.4%, while for the rice straw filler in AC-13 mixtures, it was 20%. The mechanisms of rice straw fibre and filler added in asphalt mixtures to strengthen their road performance were binder adsorption and reinforcement effect through scanning electron microscope (SEM) images. Furthermore, rice straw filler also contributed to void filling within asphalt mixtures.