Reuse of Electric Arc Furnace Steel Slags in Asphalt Pavement Mixtures

Augusto Cannone Falchetto,Ki Hoon Moon 한국도로학회 2014 한국도로학회 학술발표회 논문집 Vol.2014 No.9

The potential of marginal materials as components of road infrastructures has been studied for many years. The list of materials includes non-traditional natural materials (rocks and soils), industrial by-products (from metallurgical industry, thermal electric power stations, and chemical industry) and wastes (mining and quarrying, municipal, industrial and demolition wastes). Among these materials, Electric Arc Furnace Steel Slags (EAFSS) presents physical-mechanical characteristics and full chemical compatibility with the hydrocarbon binders used in road construction and, therefore, have high potential for being re-used. This paper presents the results of a laboratory study conducted to verify the suitability of a particular type of Electric Arc Furnace Steel Slag (EAFSS) to be recycled in the aggregate skeleton of dense graded and porous asphalt mixtures for pavements application. One dense graded mixture for wearin gcourse(WCAC), one Stone Mastic Asphalt(SMA) and one Porous Asphalt(PA) were prepared and compacted for this purpose. The computed results of Marshall Stability, Flow and Indirect Tensile Strength (ITS) values are presented in Table 1.

Remarks on the use of Electric Arc Furnace (EAF) Steel Slag in Asphalt Mixtures for Flexible Pavements

Augusto Cannone Falchetto,문기훈 한국도로학회 2015 한국도로학회논문집 Vol.17 No.1

PURPOSES: This paper, presents the results of a laboratory study aimed to verify the suitability of a particular type of Electric Arc Furnace (EAF) steel slag to be recycled in the lithic skeleton of both dense graded and porous asphalt mixtures for flexible pavements. METHODS : Cyclic creep and stiffness modulus tests were performed to evaluate the mechanical performance of three different asphalt mixtures (dense graded, porous asphalt, and stone mastic) prepared with two types of EAF steel slag. For comparison purposes, the same three mixtures were also designed with conventional aggregates (basalt and limestone). RESULTS : All the asphalt mixtures prepared with EAF steel slag satisfied the current requirements of the European standards, which support EAF steel slag as a suitable material for flexible pavement construction. CONCLUSIONS : Based on the experimental work, the use of waste material obtained from steel production (e.g. EAF steel slag) as an alternative in the lithic skeleton of asphalt mixtures can be a satisfactory and reasonable choice that fulfills the “Zero Waste”objective that many iron and steel industries have pursued in the past decades.

Feasibility analysis of taconite aggregate application by means of composite pavement structure design simulation using MEPDG

Augusto Cannone Falchetto,문기훈,조상갑 한국아스팔트학회 2022 한국아스팔트학회지 Vol.12 No.1

It is well known that application of alternative aggregate material in asphalt pavement area is crucial not for saving construction budget but for mitigating environmental pollution. Several research efforts: for finding alternative aggregate material, were performed in U.S. during the past decades. One of the research achievements is application of taconite aggregate: a byproduct of taconite mining industries in northern Minnesota, U.S., in asphalt pavement construction. Some studies performed performance evaluation of taconite aggregate added mixture with various mechanical testing procedure. However, not many studies considered pavement design performance simulation, evaluation and comparison in case of taconite aggregate application. In this paper, performance evaluation of taconite aggregate mixture by means of composite pavement design simulation using AASHTOWare-Pavement (MEPDG: Mechanical-Empirical Pavement Design Guide) was considered. Reasonable and comparable pavement performance was found when taconite aggregate is applied compared to the conventional asphalt mixture.

Mechanical performance evaluation of taconite aggregate in asphalt pavement construction

Augusto Cannone Falchetto,문기훈,조상갑 한국아스팔트학회 2022 한국아스팔트학회지 Vol.12 No.1

Using alternative aggregate source is essential in asphalt pavement industry not only for saving construction budget but also for mitigating environmental pollution issue. In U.S. northern Minnesota territory, amount of taconite aggregate: a byproduct of taconite mining industries, are produced annually. If taconite aggregate is successfully used as an alternative aggregate source, more economical and environment friendly asphalt mixture can be achieved. Many studies presented the possibility of taconite aggregate application in road construction. In this paper, suitability investigation of using taconite aggregate is performed by means of mechanical test: low temperature Indirect Tensile (IDT) creep test. A parameter for low temperature cracking resistance: creep stiffness (and corresponding relaxation modulus) result, is computed then compared visually. It was found that the asphalt mixture mixed with coarse taconite aggregate and limestone filler presented reasonable mechanical performance compared to the conventional asphalt mixture. This finding provides possibility of taconite aggregate application in actual asphalt pavement construction.

Generating 2D Three-phase Asphalt Mixture Representation Using advanced Digital Image Processing (DIP) techniques

Augusto Cannone Falchetto,KiHoon Moon 한국도로학회 2015 한국도로학회 학술발표회 논문집 Vol.2015 No.10

Analyzing asphalt mixture images can provide crucial information not only for generating advanced geometry structure in several numerical computations (i.e. FEM and/or DEM) codes, but also for numerically evaluating the material microstructure. It is well known that 3D X-Ray Computer Tomography (CT) can provide accurate and realistic microstructure information of asphalt mixtures; however, this technology still presents two limitations: 1) the equipment is very expensive and, therefore, only few pavement agencies can afford it, and 2) the software required to generate realistic image of asphalt mixture with three-phase structure (aggregate, asphalt binder and air-voids) is based on a global thresholding algorithm which cannot be easily accessed and edited by users and practitioners. In this paper, accurate and realistic 2D three-phase asphalt mixture images were generated using an advanced DIP analysis code (implemented on MATLABTM) and a common flatbed scanner, which can be easily purchased at relatively low price. The threshold algorithm was developed based on the computed results of Gmm (maximum specific gravity), Gmb (bulk specific gravity), VMA (voids in mineral aggregates) of given asphalt mixtures which can be experimentally obtained in a laboratory environment. 2D three-phase images of asphalt mixtures were derived from grey scale images (color intensity from 0 to 255) obtained from original RGB (Red-Green-Blue) scale images with a dual-threshold computation techniques (i.e. one step for computing air voids phase, T1, and a second step for computing asphalt binder (and/or mastic) phase, T2). An example of DIP analysis results is shown in Figure 1. Based on the computation results, quite accurate and good visual agreement was observed between RGB scale image and DIP analyzed image. The findings indicate that this advanced DIP analysis technique can provide reliable geometry and microstructural information for several numerical simulations such as finite element method (FEM) and discrete element modeling (DEM). This research work represents a solid base for performing simple 2D microstructure analysis using 2- and 3-point correlation function and for developing the Moon Cannone Falchetto (MCF) model which will be introduced in the next annual KSRE conference.

MN/Road 시험포장 구간내의 공기량 측정 및 결과값 분석을 통한 RAP 및 저온 아스팔트(WMA) 혼합물의 특성 평가

Ki Hoon Moon,Augusto Cannone Falchetto,Jin Hoon Jeong 한국도로학회 2014 한국도로학회논문집 Vol.16 No.4

PURPOSES: This research is to evaluate the mechanical performance of different types of Hot Mix Asphalt (HMA) pavement cells prepared for MN/Road field testing section through an extensive experimental analysis of air voids and simple statistical evaluation tools (i.e. hypothesis test). METHODS: An extensive experimental work was performed to measure air voids in 82 asphalt mixture cores (238 samples in total) obtained from nine different types of road cell located in MN/Road testing field. In order to numerically and quantitatively address the differences in air voids among the different test Cells built in MN/Road, a simple statistical test method (i.e. t-test) with 5% significance was used. RESULTS: Similar trends in air voids content were found among the mixtures including conventional HMA, Reclaimed Asphalt Pavement (RAP) and Warm Mix Asphalt (WMA) combined with taconite aggregate this provides support to the use of RAP and WMA technology in the constructions of asphalt pavement. However, in case of acid modified HMA mixtures, significant differences in air void content were observed between on the wheel path and between wheel path location, which implies negative performances in rutting and thermal cracking resistances. Conclusions : It can be concluded that use of RAP and WMA technology in the construction of conventional asphalt pavement and the use of PPA (Poly Phosphoric Acid) in combinations with SBS (Styrene Butadiene Styrene) in asphalt binder production provide satisfactory performance and, therefore, are highly recommended

Using Recycled Asphalt Materials as an Alternative Material Source in Asphalt Pavements

문기훈,Augusto Cannone Falchetto,Mihai Marasteanu,Mugurel Turos 대한토목학회 2014 KSCE Journal of Civil Engineering Vol.18 No.1

Using recycled materials in pavement applications is a viable option to reduce costs and limit the environmental impact of road construction. During the past decades, many agencies in the U.S. have investigated the effect on pavement performance of adding Reclaimed Asphalt Pavement (RAP), and, more recently, Recycled Asphalt Shingles (RAS) to asphalt mixtures, and limits were proposed on the amount of recycled materials which can be used. This paper investigates the effect of adding both RAP and RAS to virgin asphalt mixtures by means of a simple low temperature creep test performed on asphalt mixture beams. From the experimental work, creep stiffness, m-value, thermal stress and critical cracking temperature are calculated and compared statistically and graphically. Based on the results, it is concluded that most of the mixtures prepared with combinations of RAP and RAS perform similarly to standard mixtures at low temperature. For a limited number of mixtures, a negative effect is observed.

Development of High Performance Asphalt Mastic using Fine Taconite Filler

문기훈,Augusto Cannone Falchetto,박주영,정진훈 대한토목학회 2014 KSCE Journal of Civil Engineering Vol.18 No.6

Low temperature cracking is a very serious distress for asphalt pavements built in Northern U.S. and Canada. As temperaturerapidly decreases, thermal stresses develop in the restrained asphalt surface layer and, when the temperature reaches a critical value,cracking occurs. A “simple” solution to overcome this problem is to use a very soft asphalt binder with high relaxation properties,which limits the accumulation of high stress and the formation of cracks. However, these types of binder may lead to significantpermanent deformation at high temperature (e.g., rutting) and, therefore, cannot be used for real pavement constructions. In thisresearch, the possibility of obtaining stiffer asphalt binders by adding fine taconite filler available in Minnesota was investigated. Twodifferent types of asphalt binders were selected and from each binder, three different types of asphalt mastics were prepared based onthe amount (i.e., level) of taconite particles used as filler: 5%, 10% and 25%. Bending Beam Rheometer (BBR) and Dynamic ShearRheometer (DSR) tests were performed to evaluate the low and high temperature properties of asphalt binder and correspondingmastics. From these experimental works, creep stiffness, m-value, thermal stress and shear complex modulus were calculated andthen graphically and statistically compared. It was observed that asphalt mastic containing 5% taconite filler presents similarproperties at low temperature and better performances at high temperature compared to the corresponding asphalt binder. On theother hand, asphalt mastics containing higher amount of taconite fines (10% and 25%) are much more brittle compared to the originalbinder at low temperature, even though higher rutting resistance was observed at high temperature.

Microstructural Investigation of Hot Mix Asphalt (HMA) Mixtures using Digital Image Processing (DIP)

문기훈,Augusto Cannone Falchetto 대한토목학회 2015 KSCE JOURNAL OF CIVIL ENGINEERING Vol.19 No.6

It is well known that Nominal Maximum Aggregate Size (NMAS) significantly affects several mechanical properties of asphalt pavement layers both at low and high temperatures. Two different aggregate NMAS, 9.5 mm and 12.5 mm, are commonly used for surface layer mixture. Most of the past research studies investigated the effect of different aggregate NMAS on asphalt mixture properties through experimental testing, while the impact of NMAS on asphalt mixtures microstructure has received little attention. In this paper, asphalt mixtures with two NMAS, 9.5 mm or 12.5 mm, two air voids percentages, 4% and 7%, and two binder contents, 4% and 7%, were prepared. Then, the effect of aggregate NMAS on materials properties was investigated by performing low temperature creep test of asphalt mixture through the Bending Beam Rheometer (BBR) and advanced Digital Image Processing (DIP) analysis of two-dimensional images of asphalt mixture combined with numerical evaluations of 2- and 3- point correlation functions. As a result, asphalt mixtures containing smaller NMAS showed higher stiffness compared to those prepared with larger aggregates at low temperature. The spatial distributions of aggregates, asphalt mastic, and air voids were not significantly affected by the addition of aggregates with different NMAS. However, an increase in Auto Correlation Length (ACL) was observed for asphalt mixtures having smaller NMAS, which suggests that low temperature creep properties are associated to ACL.

Performance Evaluation of RAP and WMA Mixtures Located in MN/Road Test Cells through Air Voids Analyses

문기훈,Augusto Cannone Falchetto,정진훈 한국도로학회 2014 한국도로학회논문집 Vol.16 No.4

PURPOSES: This research is to evaluate the mechanical performance of different types of Hot Mix Asphalt (HMA) pavement cells prepared forMN/Road field testing section through an extensive experimental analysis of air voids and simple statistical evaluation tools (i.e. hypothesis test). METHODS: An extensive experimental work was performed to measure air voids in 82 asphalt mixture cores (238 samples in total) obtainedfrom nine different types of road cell located in MN/Road testing field. In order to numerically and quantitatively address the differences in airvoids among the different test Cells built in MN/Road, a simple statistical test method (i.e. t-test) with 5% significance was used. RESULTS: Similar trends in air voids content were found among the mixtures including conventional HMA, Reclaimed Asphalt Pavement(RAP) and Warm Mix Asphalt (WMA) combined with taconite aggregate this provides support to the use of RAP and WMA technology in theconstructions of asphalt pavement. However, in case of acid modified HMA mixtures, significant differences in air void content were observedbetween on the wheel path and between wheel path location, which implies negative performances in rutting and thermal cracking resistances. Conclusions : It can be concluded that use of RAP and WMA technology in the construction of conventional asphalt pavement and the use ofPPA (Poly Phosphoric Acid) in combinations with SBS (Styrene Butadiene Styrene) in asphalt binder production provide satisfactoryperformance and, therefore, are highly recommended