Voids In Mineral Aggregate Research Articles

The characteristics of stability test using Bantak as the main aggregate

This study aims to determine the characteristics of the stability test using Bantak as the main material. Fundamental studies in terms of the characteristics of Stability values include Density (Density), Flow (melting), VIM (Void in Mix), VMA (Void in Mineral Aggregate), VFB (Void Filled Bitumen), and Marshall Quotient (MQ). This study uses an experimental test method consisting of different bitumen content variants, respectively, 5%, 5.5%, 6%, 6.5%, and 7%. Each variant consists of three samples of the test object. The research was carried out at the building materials laboratory, Faculty of Engineering, Universitas Negeri Yogyakarta. The implementation stages include inspection of AC 60/70, an inspection of aggregates (fine aggregate and coarse aggregate), an inspection of fillers, and manufacturing mixed specimens and stability tests with various characteristics. The results of the research showed that the average value of stability, density, flow, void in the mix, void mineral aggregate, void filled bitumen, and Marshall quotient was 1156.44 kg, 2.33 gr/cc, 3.07 mm, 5.20 %, 13.92% 60.10% and 377.28 kg/mm. Finally, Bantak aggregate can be used as an alternative in the manufacture of hot asphalt mixtures because the research performance data meet the requirements for accepting Indonesian national standards. Its abundant availability makes Bantak a solution in exploiting Merapi material, which is very influential on the environmental impact and improves residents' economy in the quarry area.

Pengaruh Rendaman Air Laut Pasang Surut terhadap Campuran Lapis Aspal Beton AC-WC dengan Modifikasi Steel slag Ramah Lingkungan

Road pavement near coastal area has greater chance for seawater immersion. Along the road of Pantai Utara especially on Jalan Kaligawe Raya, Semarang, Jawa Tengah, tidal seawater flood often occurs. Road pavement that is immersed by water is potentially damaged since water is one of the causing factors of damage in road pavement. Recurring weight also will decrease the design life and the road degrades faster. The buildup of unused waste from steel factory can be an alternative material for modified asphalt mix. The test result of 6, 12, and 24 hours seawater immersion indicated poor marshall characteristic value marked by the decrease of density value, VFA (Void Filled Asphalt), stability, and MQ (Marshall Quotient), and indicated the increase in VIM (Void In the Mix), VMA (Void in Mineral Aggregate), and flow.

Development of a Balanced Mix Design Method in Oregon to Improve Long-Term Pavement Performance

Most state Departments of Transportation (DOTs) and asphalt contractors do not think that commonly used asphalt mixture properties, such as voids in mineral aggregate (VMA), voids filled with asphalt (VFA), and dust-to-binder ratio, reflect the long-term performance of asphalt mixtures. In addition, there are several new additives, polymers, rubbers, and high-quality binder types incorporated into asphalt mixtures today. Volumetric mixture design methods are not capable of capturing the benefits of using all these new technologies on asphalt mixture performance. Furthermore, the interaction of virgin binders with reclaimed asphalt pavement (RAP) mixtures with high binder replacement contents and the level of RAP binder blending into the asphalt mixture are still not well understood. Because of all these complications related to the more complex structure of asphalt mixtures, simple volumetric evaluations to determine the optimum binder content may not result in reliable asphalt mixture designs. Two volumetrically identical mixtures may provide completely different rutting and cracking performance according to laboratory tests. For all these reasons, in this study performance tests for rutting and cracking are incorporated into current asphalt mixture design methods to make it possible to validate or revise the optimum binder content determined by the volumetric mix design method (the only method currently used for asphalt mix design).

Major application and impact after modified bituminous with Nitrile rubber and Thermoset: An analysis

India is emerging as an automobile hub and has adequate production capacity of nitrile to cater to the present demand. However with the passage of time huge waste of nitrile is likely to be created which may become a major problem for its disposal. Nitrile has certain unique properties which are suitable for the road surface viz. resistant to oil, resistant to fuels, resistant to acids, high tensile strength etc. Some research has been carried out using nitrile in bitumen and the results have been encouraging. So far research has only been carried out using Nitrile rubber with different grades of bitumen.Now thermosets namely Bakelite, Furan Resin & Epoxy Resin have been used as a partial replacement of bitumen. In this research a 81 combination of Nitrile Rubber and Thermosets (Bakelite, Furan Resin & Epoxy Resin) shall be replaced with bitumen to prepared a Modified Bituminous Mix, whose properties was studied upon.To determine the optimum bitumen content (OBC) of mixes and to predict different Marshall requirements, the Marshall test is easy, economical, and widely available: Marshall consistency, flow value, air voids, mineral aggregate voids, and bitumen filled voids 5 percent, 5.5 percent, 6 percent, 6.5 percent for each of three styles of moulds were observed under 81 thermoset variations. We observed Indirect Tensile (IDT) Strength and TSR with unconditioned and conditioned would be enhanced after equal distribution of Nitrile Rubber and Thermosets (Bakelite, Furan Resin & Epoxy Resin as filler in modified bituminous . The testresults indicated that addition of Nitrile Rubber and Thermosets (Bakelite, Furan Resin & Epoxy Resin as filler remarkably improves the engineering properties of both mixes considered.

Effects of Crushed Glass Waste as a Fine Aggregate on Properties of Hot Asphalt Mixture

The recycling of waste requires large areas; besides recycling wastes to their origin is often economically and environmentally costly. Glass is considered as a solid waste that is difficult to dispose of; it doesn't degrade nor burn. Since glass is a silicic substance with similar properties to aggregates, it can be recycled in asphalt mixtures. This research aims to determine optimum binder content (OBC) of conventional hot asphalt mixture (HMA), (control mixture), and investigate the effect of crushed glass waste (CGW), on its properties. In this work, several percentages of CGW (10%, 15%, 20%, and 25%) have been used as a partial substitution for the weight of fraction size 2.36-0.075mm of natural aggregate to prepare glass-contained asphalt mixtures and compare their properties with the control mixture. Mix design by Marshall method was used, and the properties according to Iraqi standards (SORB/R9,2003), for binder layer, were found, as well as conducting of Retained Marshall stability (RMS), indirect tensile strength (IDT), and tensile strength ratio (TSR), tests on mixtures, as performance tests. The results showed that the OBC of the control mixture was 5% wt., and the Marshall stability and flow values of glass-contained asphalt mixtures were oscillating around the values of the control mixture. The air voids, voids in mineral aggregate, and bulk density were reduced regularly as CGW increased. Also, it was observed from the results that the glass-contained mixtures have good performance properties. However, all results conformed to the standards (SORB/R9, 2003). So, the incorporation of CGW in HMA for the binder layer is feasible.

The Effect of Pulp Cane Ash Filler and Concrete Waste as Replacement of Coarse Aggregate to The Marshall Characteristic on Asphalt Concrete Mixtures

Asphalt quality improvement efforts starts from the construction of buildings, infrastructure and roads continue to be developed. This development will increase the need for material used. This study aims to (1) determine the effect of bagasse ash filler with concrete waste as a coarse aggregate on Marshall characteristics on asphalt concrete mixture, in terms of density, VIM (void in the mix), VMA (voids in mineral aggregates), VFA (void filled with asphalt), stability, flow (melting), and MQ (Marshall quotient). (2) As well as knowing the suitability of the Marshall test results with the requirements of Bina Marga 2010. This study uses an experimental testing method implemented by making test specimens following existing standards and conditions, as well as the use of bagasse ash as filler material and concrete waste as a substitute for coarse aggregate in asphalt mixture, with a variation of the percentage using bagasse ash filler with 0%, 5%, 10%, and 15% content. For each treatment, three samples were made. The results of testing the concrete asphalt mixture are: (1) density 2.16 gr/cc, VIM 11.56%, VMA 17.39%, VFA 33.91%, stability 3263.92 kg, flow (melting) 2.03 mm, MQ 2353.70 kg / mm. (2) Test results for all specimens, with the addition of bagasse ash filler as asphalt mixture filler, have met the 2010 Bina Marga requirements, as a minimum requirement for the highway, with stability values of more than 800 kg and flow values between 2 mm to 4 mm.

Effects of Polyethylene Terephthalate and Crumb Rubber on Selected Properties of Asphaltic Concrete

This study investigated the combined effects of polyethylene terephthalate (PET) and crumb rubber (CR) as modifiers on some properties of asphaltic concrete. Asphaltic concrete materials were obtained from a construction site. CR of 9.5 mm size was obtained by sieving, while PET bottles were collected, sorted, washed, dried and shredded by mechanical means. The physical properties of these materials were determined following standard procedure. Bitumen was modified by wet process with PET and characterised. Asphaltic concrete samples with partial replacement of coarse aggregate in the mix with CR were prepared. Samples without modifiers were also prepared as control. These were subjected to Marshall Stability test. The percentage variation for stability and flow between the control and the modified mixes, were 27 % and 0.29 % respectively, while those of the volumetric properties of bulk density, voids filled bitumen (VFB), air voids (VA) and voids in mineral aggregate (VMA) were 0 %, - 0.13 %, 0 % and 0 % respectively. It was concluded that, there was no difference between the flow and volumetric properties of the control and modified mixes.
 Keywords: Polyethylene terephthalate, crumb rubber, asphaltic concrete, stability, flow, volumetric parameters

Strength improvement of cement emulsified asphalt mixture through aggregate gradation design

Aggregate gradation greatly affects properties of cement emulsified asphalt mixture (CEAM). In this work, an aggregate design based on fractal theory method (FTM) was put forward and trial calculation method (TCM) was adopted to design aggregate gradation of the mixtures. Properties of the mixtures, Marshall stability and splitting strength, were adopted as indexes to evaluate effects of the two methods. In addition, other properties of the mixtures such as, voids in mineral aggregates, porosity and residual stability of the mixtures were carried out to verify effects of the two methods. Furthermore, the gradation obtained by the two methods was simulated based on partical flow code in two dimension (PFC2D). The results show that the aggregate with the optimum gradation possesses dense skeleton structure and excellent stability. Particle contact force is relatively uniform distribution. Besides, voids in the mineral aggregate, porosity and residual stability of the mixture designed by FTM were superior to that designed by TCM. It was confirmed that the aggregate gradation design method with fractal model established in this work is reasonable and effective to improve strength of cement emulsified asphalt mixture.

Recycled Polyethylene Terephthalate as Reinforcement Additive of Asphalt Mixture for Pavement Application

This study explores the effect of incorporating recycled polyethylene terephthalate (PET) into asphalt pavement mixtures. The performance characteristics were observed to determine if the mechanical properties of the resulting mixture had significantly improved. The PET-asphalt mixtures were prepared using the dry method and were then evaluated based on the Marshall flow and stability tests, as well as its volumetric properties – such as air voids, voids filled with asphalt (VFA), voids in mineral aggregates (VMA), bulk specific gravity (BSG), and maximum specific gravity (MSG). Results show that the optimum PET content in the mixture is 15% by weight of asphalt binder at 5% binder composition of the overall asphalt pavement mixture. The stability was observed to increase by 14.2% compared with the conventional mix and each sample passed the standards set by the Asphalt Institute. Based on the results, it can be concluded that at certain amounts, the addition of PET improves the Marshall properties of the pavement.

Material Properties and Environmental Benefits of Hot-Mix Asphalt Mixes Including Local Crumb Rubber Obtained from Scrap Tires

This paper presents the results of a laboratory-based experimental investigation on the properties of asphalt binder and hot-mix asphalt (HMA) mixes modified by locally available crumb rubber, which was used as a partial replacement of asphalt by weight. In this study, fine crumb rubber with a particle size in the range of 0.3–0.6 mm, obtained from scrap tires, was added to the asphalt binder through the wet process. Crumb rubber contents of 5%, 10%, 15%, and 19% by weight of asphalt were added to the virgin binder in order to prepare the modified asphalt binder samples, while the unmodified asphalt binder was used as the control sample. The crumb rubber modified binder samples were examined for measuring viscosity indirectly using the penetration test, and temperature resistance using the softening point test. Later, both the modified and unmodified asphalt binders were used to produce HMA mixes. Two categories of HMA mix commonly used in Malaysia—namely, AC 14 (dense-graded) and SMA 14 (gap-graded)—were produced using the modified asphalt binders containing 5%, 10%, 15%, and 19% crumb rubber. Two AC 14 and SMA 14 control mixes were also produced, incorporating the unmodified asphalt binder (0% crumb rubber). All of the AC 14 and SMA 14 asphalt mixes were examined in order to determine their volumetric properties, such as bulk density, voids in total mix (VTM), voids in mineral aggregate (VMA), and voids filled with asphalt (VFA). In addition, the Marshall stability, Marshall flow, and stiffness of all of the AC 14 and SMA 14 mixes were determined. Test results indicated that the modified asphalt binders possessed higher viscosity and temperature resistance than the unmodified asphalt binder. The viscosity and temperature resistance of the asphalt binders increased with the increase in their crumb rubber content. The increased crumb rubber content also led to improvements in the volumetric properties (bulk density, VTM, VMA, and VFA) of the AC 14 and SMA 14 mixes. In addition, the performance characteristics of the AC 14 and SMA 14 mixes—such as Marshall stability, Marshall flow, and stiffness—increased with the increase in crumb rubber content. However, the AC 14 mixes performed much better than the SMA 14 mixes. The overall research findings suggest that crumb rubber can be used to produce durable and sustainable HMA mixes, with manifold environmental benefits, for use in flexible pavements carrying the heavy traffic load of highways.

Influence of polyethylene from waste pure water sachet on properties of hot mix asphalt

This work evaluate the influence of waste pure water sachet (WPS) as a modifier in Hot Mix Asphalt (HMA). The properties of the constituent materials were determined. Modified HMA samples were prepared at varying concentration of 2, 4, 6, 8 and 10% WPS content by weight of the Optimum Binder Content (OBC). The properties of the modified HMA were determined using Marshall Method of mix design. The properties of the constituent materials showed that they are suitable for HMA production. The modified bitumen showed an increase in softening point (61 – 73.5%), flash point (258 – 2820C), fire point (289 – 3110C) and ductility (92.67 –118.67cm) as the WPS content increases from 2% to 10% while decrease in penetration (62.33 – 56.5mm) as WPS content increases from 2% to 6%. Stability and Bulk density increases from 4.64kN to 8.84kN and 2.21g/cm3 to 2.34g/cm3 respectively while flow, voids in mineral aggregates (VMA) and Air voids decreases from 3.6 to 2.98mm, 23.85 to 20.16% and 19.73 to 13.97% respectively as the WPS content was increased from 2 to 8%. An optimum polyethylene from WPS modifier content of 8% by weight of the OBC is recommended for use in the HMA.
 Keywords: Bitumen, Hot Mix Asphalt, Pure Water Sachet, modified bitumen, Marshall Properties, Polyethylene.

The performance of stability test using Bantak aggregate and AC50/70 as polymer on Marshall characteristic

This study aims to determine Marshall's characteristics using asphalt binder modified polymer AC 50/70 (Starbit E-55) using local Bantak material. The test method used is a hot mix asphalt (Hot Mix) with the Marshall method. The asphalt content used was 5% successively; 5.5%; 6%; 6.5%; and 7% consisting of 3 specimens for each variant. The research was carried out at the Material Laboratory of the Department of Civil Engineering and Planning, Faculty of Engineering, Yogyakarta State University. The results of the Marshall characteristic performance test at the Optimum Asphalt Level (KAO) 6.5% are as follows: Marshall stability mean value is 1197.6 kg, Density mean value is 2.34 gr/cc, the mean value of melt (Flow) is 3, 1 mm, the mean value of VIM (Void in Mix) was 4.83%, the mean value of VMA (Void in Mineral Aggregate) was 13.40%, the mean value of VFB (Void Filled Bitumen) was 60.61%, and the mean value of MQ (Marshall Quotient) 391.08 kg/mm.

Modeling Marshall Test Results of Hot Mix Asphalt Using Nonlinear Genetic Programming Techniques

The Marshall test method is widely used for the design and control of hot mix asphalt (HMA). The Marshall and modified Marshall mix design method is most widely used in Iran. Determining Marshall test results (Marshall stability, flow, and Marshall quotient (MQ)) are time consuming. Therefore, using new and advanced methods to determine the results of Marshall testing is essential. In this study, the genetic programming method based on artificial intelligence was used for the prediction of Marshall test results. Input variables in the genetic programming models use the volumetric properties of standard Marshall specimens such as air voids, voids in mineral aggregate (VMA), and voids filled with asphalt (VFA). Also, multiple linear regression models were used as the base model to evaluate the models presented by the genetic programming method. The results indicated that the proposed methods are more efficient than the laboratory costly method and the performance of the genetic programming model is completely satisfactory in comparison to the base model and has been able to predict the results of Marshall testing based on the input parameters. The GP models have a higher coefficient of determination and fewer errors than MLR models. The presented models will also help further researchers willing to perform similar studies, without carrying out destructive tests.

Investigating the Effect of Olive Husk Ash on the Properties of Asphalt Concrete Mixture

Technology in transportation used available resources to make it safe, fast, suitable, easy, economic, and environmental to transport people and goods. Olive Husk became an environmental problem as waste materials especially in the Middle East where huge quantities are found. The objective of this research is to investigate the effect of addition of Olive Husk Ash (OHA) on the properties of asphalt concrete mixtures. Marshall Test was used to perform the asphalt concrete mixture by the addition of OHA to the binder of asphalt; different percentages of OHA (0, 5, 10, 15, and 20%) by volume were added to the binder. Five percent of asphalt cements (5, 5.5, 6, 6.5 and 7%) by weight and limestone aggregate were used for preparing asphalt mixture specimens to find the optimum content of asphalt that could be used in the binder. Tests on flow, stability, air void percentage and void in mineral aggregate, retained stability, stiffness, and retained stiffness were made. The principle results on OHA as filler in Asphalt binder improves the Marshall Stability, and void in mineral aggregate and decrease in flow, retained stability, stiffness, and retained stiffness with a 10%-15% of olive husk ash replacement of asphalt binder. The contribution that OHA could be used as a pavement construction material in field.

Design of asphalt mixes with steel slag aggregates using the Bailey method of gradation selection

It has been reported in the literature that the asphalt mixes containing a high percentage of Steel Slag Aggregates (SSA) are susceptible to high void space. This is one of the major reasons that SSA usage is limited to replacement of either the fine or coarse aggregates fraction, but not both by the road agencies. More void spaces in the asphalt mixes with a higher proportion of SSA can be attributed to the high specific gravity of the coarse aggregate (CA) of SSA and the adoption of weight-based gradation selection for mix design. This issue can be addressed by adopting the volume-based Bailey method. The present paper attempts to provide a framework to design asphalt mixes with a high proportion (up to 100%) SSA with aggregate fractions of varying specific gravity by employing the Bailey method of gradation selection. The study in the paper showed that by adopting the Bailey method for gradation selection, SSA mixes with Voids in Mineral Aggregates (VMA) similar to Natural Aggregate (NA) mixes can be produced despite the significant differences in specific gravities between the fine and coarse aggregate fractions. Test for mechanical properties on asphalt mixes suggested that the resilient modulus of SSA asphalt mixes can be 1.4 to 1.8 times that of NA asphalt mixes. Owing to the high particle strength of SSA combined with the predominantly cubical shape, SSA mixes were found to be relatively more resistant to rutting. Comparisons based on linear elastic analysis and design of hypothetical pavement sections indicate that the fatigue life of pavement with SSA asphalt base layers is comparable with the fatigue life of the pavement with NA asphalt mix bases. It was also observed that the asphalt mixes with SSA aggregates had shown relatively more resistance to the moisture damage.

Effect of Gradation Variability on Volume Parameter and Key Performances of HMA

The graded mineral aggregate composed of coarse aggregate, fine aggregate, and mineral powder is the main component of hot asphalt mixture (HMA), and it occupies a mass ratio of more than 95% in HMA. The gradation variability of mineral aggregate is frequently an unavoidable problem in the construction of asphalt pavement engineering. In order to investigate the effect of gradation variability on the volume parameters and key performances of HMA, the asphalt concrete with a nominal maximum particle size of 20 mm (AC20) was selected as the research carrier. Firstly, a benchmark mineral aggregate gradation (BMAG) was designed based on the theory of dense skeleton gradation presented in the paper. Secondly, six types of HMA (that is, AC20) with variable gradations were also determined and all the specimens were prepared by rotary compaction process with the same optimum asphalt content (gradation varies but asphalt content remains the same), and finally based on asphalt pavement analyzer, the performances of all the specimens of each gradation were tested. The results show that, compared with the BMAG-HMA, the volume parameters such as air voids, voids in mineral aggregate, and voids filled with asphalt of the variable-graded HMA change in different directions, but the water stability and high-temperature performance both degrade greatly. The experimental results also show the feasibility and effectiveness of the dense skeleton gradation design theory adopted in this study.

IMPROVEMENT OF MARSHALL PROPERTIES FOR HOT MIX ASPHALT BY USING CERAMIC FIBER

Many road networks are using hot mix asphalt (HMA) to construct pavement layers. The Marshall method is the common procedure used in the design of the HMA and used at the time of the construction of the roadway to quality control. The present work is using ceramic fiber as a reinforcement to improve the characteristics of the HMA. The Marshall properties are examined by several tests such as Marshall stability test, and the flow test. The group of samples was made by utilizing 0.50, 1.0, 1.5, and 2.0 percentages of ceramic fibers by the total weight of the mixture. The results of the experiment showed the maximum Marshall stability occurred at a value of 1% ceramic fiber; the flow value decreased with increasing of fiber content, and the maximum Marshall quotient occurred at a value of 1% ceramic fiber. Also, the air voids, void filled with asphalt, and the void in mineral aggregate increased with increasing ceramic fiber content.

Use of electronic waste plastic in asphalt mix with marble dust as filler

E-waste is becoming burgeoning global issue, which showcases the impacts of the same on environment and on humans. Marble cutting industries is another industry producing huge amount of marble dust as a waste which is degrading the environment. E-waste and waste marble dust can be utilized in construction industry in different forms thus helps in reducing its impact on environment. In this analysis, electronic waste plastic materials including recycled PCB’s and other PVC components of e-waste has been used as a partial replacement for coarse aggregates and marble dust is used as complete replacement for filler in asphalt mix for pavement. A significant increase of Marshall Stability and Flow Value has been observed as percentage of e-waste plastic increases. The plastic content of mix varies 0 %, 4 %, 8 % and 12 % by weight of aggregate. Plots of various Marshall Parameters such as Marshall Stability, Flow value, voids filled with bitumen, voids in mineral aggregates and unit weight against the bitumen content shows an improving trend of parameters with increasing the plastic replacement. Comparison with earlier published result shows that increasing the plastic replacement beyond 12% will have a negative influence on stability value. The recycling of e-waste plastic and marble dust in asphalt mix design for pavements provide us a better way of resource utilization in a cost-effective manner.

Investigating the Marshall and Volumetric Properties of Asphalt Concrete Containing Reclaimed Asphalt Pavement and Waste Oils Using Response Surface Methodology

This research aimed to use response surface methodology (RSM) for investigating the Marshall Stability (MS), flow and Voids in Mineral Aggregates (VMA) of asphalt concrete containing different percentages of Reclaimed Asphalt Pavement (RAP) and rejuvenated by different percentages of waste cooking and engine oil. Variables of RAP content in 3 different levels of 25, 50 and 75% (by the weight of total aggregates) and waste oils content in 3 different levels of 5, 10 and 15% (by the weight of total binder) were selected. Quadratic and linear two factor interaction models were well fitted to the experimental results. Analysis of variance showed that the models were capable to well predict the MS, flow and VMA of the mixtures, and the terms of oil and RAP content and type of oil are significant. MS, flow and VMA increased with increasing RAP content and decreased with increasing oil content. Results also reveal that higher MS, flow and VMA values are resulted by using WEO than using WCO. Some interaction effects were found between RAP content, oil content and type of oil on the responses. Optimization analysis showed that using 10.6% of WCO and 15% of WEO, allows a maximum RAP incorporation of 75 and 51.77%, respectively, by which the properties are similar to control mix. Use of the rejuvenators allows using high RAP content without sacrificing the properties of the mixtures.

Mechanical Characteristics of the Asphaltic Concrete Mixture with the Addition of Steel Fibers

Roads have the strength and durability to be able to handle the existing traffic load for their planned lifespans, and damage must be minimized. Methods of minimizing damage include self-healing. Before testing self-healing ability, steel fibers that have a solid density and as a good conductor must be tested for their mechanical characteristics in the AC-WC mixture. These consist of the Marshall characteristic tests and the volumetric characteristic test. With an asphalt content of 5.7%, the 0.25%, 0.5%, 0.75%, and 1% addition of steel fibers into the asphalt- concrete wearing-course (AC-WC) mixture increases the value of Void Filled with Asphalt (VFA), stability, and the Marshall Quotient and reduces the value of Void in The Compacted Mixture (VITM), Void in Mineral Aggregate (VMA), and flow. However the VITM value obtained is below the 3% requirement, because the number of cavities in the mixture is already close to the minimum requirement without the addition of steel fibers. Another reason is the high 5.7% asphalt content. The optimum steel fiber content, obtained using the narrow range method, is 0.625%. Based on its mechanical characteristics, steel fiber is a recommended additive.