Wearing Course Research Articles

Utilizing recycled ceramic aggregates obtained from tile industry in the design of open graded wearing course on both laboratory and in situ basis

The purpose of the research was to evaluate the technical feasibility of using porcelain and ceramic stoneware tile wastes as aggregate replacement in hot bituminous open graded wearing courses. It is believed that it would reduce the environmental effects of wastes disposal and the natural aggregate demand. The investigated bituminous mix course was an open graded wearing course. Ceramic tile industry wastes were treated to obtain recycled aggregates. These aggregates were characterized and tested to see their suitability to be utilized in bituminous mixtures. The design process of mixture consisted on the study of mixtures prepared with natural and recycled aggregates. The mixtures were produced in both the laboratory and an asphalt plant basis, evaluating the influence of in situ production and scale factors. Recycled ceramic aggregates content was established to obtain appropriate mechanical and superficial characteristics, besides maximizing re-utilization of recycled materials. Up to 30% of recycled ceramic aggregates content by aggregates weight was found to be adequate. However, the partial substitution of natural aggregate by recycled ceramic aggregates involved higher water sensitivity in the mixture. The open graded wearing course with recycled ceramic aggregates was considered to be suitable for medium to low traffic volume roads, though further research is deemed to be necessary for technical and economical viability.

The influence of Buton asphalt additive on skid resistance based on penetration index and temperature

Abstract Skid resistance on pavement surfaces can affect the safety of road users and impact their travel efficiency. This value specifies the frictional forces on the wheels of vehicles that will avoid the occurrence of slip in wet or dry conditions. This study tested skid resistance using tools a Skid Resistance Tester and a British Pendulum Tester. Analyses were performed to evaluate the surface roughness of an asphalt concrete wearing course (AC-WC) with bitumen 60/70 and a Buton asphalt additive blend with the same aggregate composition. Buton asphalt additive is made by refining bitumen rocks with low penetration. The addition of this substance reduces the penetration of asphalt at 25 °C. The tests were performed on wet surface conditions at a temperature ranging from 30 °C to 55 °C and varying penetration index in asphalt concrete mixtures. The skid resistance value decreased with increasing surface temperature. The additive caused a change in the asphalt penetration index in asphalt concrete, resulting in a higher skid resistance value than that of virgin bitumen 60/70.

Design and Construction of a Full-Scale Test Section with Asphalt Rubber Gap-Graded Wearing Course Mixture

A full-scale test section with asphalt rubber gap-graded wearing course mixture was designed and constructed on a major infrastructure as part of a regional research and implementation project. Standard and performance-related laboratory tests were carried out in order to select constituent materials, define the job-mix formula and monitor construction operations. Gaseous emissions of the bituminous mixture sampled during laying were analyzed to assess the potential risks to which labourers are exposed during paving. Environmental compatibility was also evaluated by performing laboratory leaching tests. Based on the results obtained in the investigation, technical guidelines were validated and enhanced.

Pavement Surface Performances Evolution: an Experimental Application

Pavement surface performances have a great influence on road functionality and can affect user's safety, vehicle operational costs, environmental sustainability. The assessment of evolution of pavement surface performance plays a fundamental role in road pavement management and is useful in order to allocation of maintenance resources.In the light of the above, Authors introduced the first results carried out from a two-year monitoring of an experimental road section. Four different dense graded wearing courses were designed with different aggregates: limestone, basalt and expanded clay. Several surface performances were measured by different devices (Skid Tester, Sand Patch Test, Laser Profilometer).

Evaluation of the Influence of Variation of Superpave HMA Mixtures Physical Properties on Pavement Performance

For numerous years, researchers have investigated hot-mix asphalt (HMA) plant production and the relationship between measured quality control/quality acceptance (QC/QA) parameters and field performance. After 12 years of service, this study presents a statistical evaluation of the relationship between HMA plant QC/QA data, roadway density, and field performance, as measured by international roughness index (IRI), rutting, and random cracking. Three Louisiana Superpave projects constructed in 1999 utilizing wearing and binder course mixtures were evaluated. Results indicated that, as Superpave Gyratory Compaction levels increased, roadway density variability increased. Generally, QC test results were less variable than QA test results and voids filled with asphalt (VFA) showed the highest variability between measured volumetric parameters. Statistical analysis indicated that the coarse aggregate portion (19.0 mm, 9.5 mm, and 4.75 mm sieves) and the 0.075 mm sieve had an effect on voids in the mineral aggregate (VMA), VFA, and air voids (V a). The percentage of asphalt cement significantly affected rutting and random cracking; the top size aggregate at or near the nominal maximum size aggregate, the 4.75 mm, and the 0.075 mm sieves had an effect on rutting, random cracking, and IRI for the HMA mixtures evaluated.

Noise-reducing asphalt rubber surfaces in China

In the earlier part of 2004, the state-of-the-art and practice of asphalt-rubber (AR) surfaces as used and applied in the United States of America (USA) to reduce traffic noise was presented in China. AR surfaces have been used in the USA for many years to reduce the traffic noise. The AR surfaces can be applied as the final wearing course on conventional concrete and/or asphalt pavements. In the USA, the States of California and Arizona, and several others have successfully employed thin wearing courses (12.5 to 40 mm) of AR to reduce highway noise. Following this early exposure to the AR technology, China began to experiment and later used AR to reduce noise, as well as to provide a durable and good quality skid resistant wearing courses. This paper reports the progress of use of AR in China and the noise data from various surfaces in China. These surfaces included Stone Mastic Asphalt, Polymer Asphalt, Asphalt Rubber Asphalt Concrete and Asphalt Rubber Open Graded Friction Course.

Modeling of viscous bituminous wearing course materials on orthotropic steel deck

This paper deals with the influence of a bituminous mix surfacing on the orthotropic deck bridges. These researches are part of a French national project “Orthoplus”, which is briefly introduced. The approach to take into account the surfacing and to develop calculation tools is explained. First the behavior of the different bituminous constituent materials is investigated. A linear visco-elastic modeling is proposed with a rheological model, previously developed at the Civil Engineering and Buildings Department (“DGCB”) of University of Lyon/ENTPE. This model was implemented in a Finite Elements code, which enables the simulation of any orthotropic structures. In order to validate these developments, two orthotropic structures are studied, including the highest bridge in the world, the Millau Viaduct (France). In situ measurements were especially carried out on the Millau Viaduct. The analysis is also performed on the French five-point bending fatigue test used at the EIFFAGE Travaux Publics research center in parallel to the construction, in 2004, of the Millau Viaduct. Focus is made on comparisons between experimental data and simulations results.

Study the Use of Cement and Plastic bottle Waste as Ingredient Added to the Asphaltic Concrete Wearing Course

This paper is concerned with the possibility of using plastic bottle waste as an ingredient to the Asphaltic Concrete Wearing Course (AC-WC). This research is explores the effect of adding plastic and cement as ingredient to the mixture of asphalt concrete on the characteristics of Marshall. Plastics that are added are 2:4 and are 6% in weight. It was observed that the optimum bitumen content on the addition of 4% plastic and Marshall stability increases by 19% compared to the AC-WC without addition of plastic. The positive effect of plastic bottle on the characteristics of Marshall, along with its enviromental advantages, make this material a feasible additive.

Basic Performance of the Composite Deck System Composed of Orthotropic Steel Deck and Ultrathin RPC Layer

Fatigue damage in a conventional orthotropic steel bridge deck system poses a formidable challenge to bridge engineers all over the world because of ever-increasing heavy traffic volumes and higher wheel loads over the past decade. An effective solution may be to enhance the stiffness of the bridge deck to reduce the fatigue stress amplitude of its components. This paper proposes an innovative composite bridge deck system that consists of an orthotropic steel deck stiffened with a 45-mm reactive powder concrete (RPC) layer. Based on the analysis of HuMen Bridge in China (a suspension bridge with a conventional orthotropic steel bridge deck system with span length of 888 m) and two types of full-scale model tests, a comparison investigation is conducted between a conventional orthotropic deck system where the asphalt wearing course has been ignored and the proposed orthotropic deck system that includes an integral concrete wearing course, and the proposed composite bridge deck system proves to be considerably effective in reducing the stress range caused by service vehicle loads when applied to long-span steel suspension bridges. The thin RPC layer can be reliably integrated with the deck plate through stud shear connectors, and no shrinkage cracking occurs on the surface of the RPC layer that is cast on the deck plate. The fact that the tensile stress of the RPC layer is up to 42.7 MPa before cracking occurs demonstrates that cracking will not appear in the RPC layer under service vehicle loads. The analysis, which is investigated on the premise that the dead load weight of the bridge deck of HuMen Bridge is approximately the same for the two different deck systems, demonstrates that the stress of the orthotropic steel deck is significantly reduced with the application of the proposed composite deck system. Analysis with a three-dimensional finite-element model indicates that the transverse tensile stress of the deck plate is reduced by 71%, while that of the connection between the deck plate and the longitudinal troughs is reduced by 72%. This indicates that the risk of causing fatigue cracks in the steel bridge deck system can be considerably reduced during the entire life cycle of the bridge.

Impact of Fine Materials Content on the Transport of Dust Suppressants in Gravel Road Wearing Courses

A significant problem when dust-suppressing agents are used on gravel roads is that they tend to leach during rainfall. The purpose of this study is to illustrate this problem by using laboratory studies and studies in situ. Both capillary rise and leaching of suppressants were examined by using cylinders filled with wearing course material. Chloride was more prone than lignosulphonate to transport upwards by means of capillary rise, and therefore, it showed a more effective performance over a longer period of time. Optimal percentages of fine material for minimal lignosulphonate and chloride leaching were found to be 15% by weight and 10–15% by weight, respectively. Ions of calcium chloride seemed to flocculate clay particles, which probably prevents them from leaching. To study the in situ longevity of fine material in general, calcium carbonate, mesa, was used as a marker. The fine material in gravel wearing courses must be replenished regularly. Mesa loss was up to 80% after 1 year.

Characterization of Mechanically Stabilized Layer by Resilient Modulus and Permanent Deformation Testing

The majority of roadways in the United States are low volume. Pavement structures for low-volume roads (LVRs) are designed according to empirical procedures that are sometimes verified by a mechanistic-based design process. The flexible pavement structure for an LVR consists of a relatively thin asphalt–concrete wearing course and an aggregate base course constructed on subgrade. An asphalt wearing course provides a good riding surface and moisture protection for the base course. Service life of a thin asphalt pavement depends on material quality and thickness of granular layers. A compelling need now exists for reducing the cost of building and maintaining the national transportation infrastructure. The limited lifespan of most construction materials due to continuing wear and tear requires more creative, innovative, economical, and sustainable roadway design techniques. Geogrid reinforcements in LVRs are seen as a particularly promising solution because they can be designed to provide an equivalent service life through use of less material. The combination of the aggregate and geogrid materials creates an improved or mechanically stabilized layer (MSL) with a significantly increased resilient modulus. The objective of this study was to use existing testing protocol to determine and to evaluate material design parameters for an unbound and a geogrid MSL. To determine the effects of an MSL, a test combination that included AASHTO T307 and NCHRP 598 was conducted on both unbound and mechanically stabilized aggregate specimens.

USING TEMPERED GLASS AS A REPLACEMENT OF ASPHALT CONCRETE WEARING COURSE

USING TEMPERED GLASS AS A REPLACEMENT OF ASPHALT CONCRETE WEARING COURSE

Methods for Quantification of Lignosulphonate and Chloride in Gravel Wearing Courses

Due to oxidation, breakdown, and leaching, dust suppressants will be lost from the gravel road surface. Methods for residual dust suppressant concentration supervision are a valuable tool for estim ...

Effects of Aging on the Mechanical Characteristics of Bituminous Binders in PAC

Wearing courses of porous asphalt concrete (PAC) are widely used in The Netherlands for noise reducing purposes. Because these mixtures have a very high void content (>20%), they are sensitive for damaging effects of climate and traffic. Especially, aging is a major concern because it makes the mixture brittle and prone to raveling. In order to be able to do meaningful tests and analyses based on laboratory produced specimens, it is important to mimic field aging as well as possible. This paper describes the results of an investigation in which the effects of well known short-term and long-term laboratory aging procedures on the rheological characteristics and chemical composition of binders, are compared with the rheological characteristics and chemical composition of field aged binders. The results obtained on field aged binders are also compared with the results of laboratory aging protocols in which a special weatherometer was used. The results clearly show that none of the laboratory procedures is capable of simulating long-term field aging. At best 2 years field aging could be simulated. Furthermore, the study showed that the way bitumens are aged in the laboratory affects the chemical composition of the binder. The paper also discusses the effect of aging on the mechanical characteristics of bituminous binders in porous asphalt concrete. It is shown that due to aging, the binder will start to behave brittle at temperatures above 0°C. Furthermore, it is shown that aging increases the tensile strength of the binder and the bituminous mastic (mixture of bitumen and filler). The strain at break however decreases as a result of aging. Fatigue testing showed that aging initially increases the fatigue resistance of the binder. However long-term aging occurring in the field after a period of more than 7 years results in a significant decrease of the fatigue resistance. Although not discussed in detail, the results show that aging reduces the stress relaxation capacity of the binder. This will negatively influence the behavior of the binder in case temperature stresses occur together with traffic induced stresses. Also, the healing capacity will be negatively influenced by aging.

Functionally Optimized Wearing Course

The preliminary findings on the design, production, placement, and early life performance of a new generation open-graded surface course [also referred to as porous friction course (PFC)] for use in Virginia are highlighted. The primary objective of the larger research project is the design of a functionally optimized asphalt concrete wearing course. Important aspects of the mix design and construction and the initial functional quality of the new surface are documented. General observations associated with the trial section and normal production and placement activities are accompanied by a summary of the quality characteristics of the material. Special emphasis is placed on the early life functional characteristics of the new wearing course. Among these key characteristics are ride quality, wet skid resistance, and tire–pavement noise. Observations made during trial production and placement led to lighter (thinner) recommended application rate and reduced asphalt concrete mix temperatures. Preliminary functional tests indicated that the PFC has exceptional early-age skid resistance, incentive-quality smoothness, and low tire–pavement noise. On the basis of initial cost and early-life functional performance, the PFC is cost-competitive with traditional mixes placed at traditional application rates (when those mixes are used for functional rather than structural improvement).

Methods for Quantification of Lignosulphonate and Chloride in Gravel Wearing Courses

ABSTRACT Due to oxidation, breakdown, and leaching, dust suppressants will be lost from the gravel road surface. Methods for residual dust suppressant concentration supervision are a valuable tool for estimating life-length and optimal application rates, and, hence, efficiency of different products. The objective of this study was to identify methods for quantitative analyses of lignosulphonate and chloride, develop and adapt the methods for application on a gravel matrix, and validate the methods using samples collected in-situ. Results strongly suggest that the reliability and repeatability of the developed methods (23% for lignosulphonate and 30% for chloride, respectively) are acceptable for determination of relative variations in residual concentrations of dust suppressed gravel wearing courses.

Construction and Performance of Pervious Concrete Overlay at Minnesota Road Research Project

Portland cement pervious concrete (PCPC) has shown great potential to reduce roadway noise, improve splash and spray, and improve friction as a surface wearing course. A study is under way at Iowa State University and the National Concrete Pavement Technology Center to develop mix designs and procedures for PCPC overlays for highway applications. A report is produced on the construction and performance of a PCPC overlay constructed at the Minnesota Road Research Project low-volume roadway test facility to determine the effectiveness of pervious concrete as an overlay. Issues related to construction of the overlay are described, as are results of field tests to characterize the condition of the pavement 7 months following construction, to determine flow characteristics of the overlay, and to characterize the tire–pavement noise of the overlay. Results of these studies show that effective PCPC overlays can be designed for wearing course applications.

Laboratory Study On The Durability Characteristics (Moisture Damage Evaluation) Of Asphalt Concrete Wearing Course (AC-WC) Utilizing Bantak And Clereng As Aggregate (Using Marshall Methods)

Laboratory Study On The Durability Characteristics (Moisture Damage Evaluation) Of Asphalt Concrete Wearing Course (AC-WC) Utilizing Bantak And Clereng As Aggregate (Using Marshall Methods)

Eaf Steel Slag Application Posibilities in Croatian Asphalt Mixture Production

This paper demonstrates the results of testing basic physical and chemical properties of steel slag generated in the steel mill of CMC Sisak d.o.o., Croatia, with the purpose of its characterization as the type of waste, i.e. by- product intended for recycling in other industries. Special attention has been directed at investigating the possibilities of it being used as substitute for natural mineral aggregates when producing asphalt mixtures. The results which were obtained by testing geometric, physical-mechanical properties, as well as the properties of duration on the specimen of electric arc furnace steel slag, have satisfied the conditions for manufacturing mixtures of the tested steel slag and natural aggregate which can be used in asphalt production. In comparison to the natural carbonate and silicate aggregates which are used in asphalt mixtures on highways and roads with heavy traffic, the examined steel slag has equally good physical-mechanical properties. Within the framework of this project, test fields have recently been constructed. The existing wearing course was replaced by an AC 11 type of asphalt, in one lane with conventional natural carbonate aggregate and in the other two lanes with slag aggregate from CMC Sisak (0/4, 4/8, 8/11). The results of measurements of skid resistance on the section constructed using natural aggregate, and the section made using steel slag aggregate, were comparable. By means of laboratory analyses and in situ monitoring it should be possible to prove that asphalt composites containing slag have sufficient durability, and can achieve and maintain the required surface characteristics for road traffic safety.

A Drainage System for Mitigating Moisture Damage to Bridge Deck Pavements

This study presents the development of a new drainage system that can quickly drain water that has penetrated into bridge deck pavements. The new drainage system is expected to significantly reduce potholes that typically lead to premature failure of pavements. This system can be established by applying a thin drainage layer between the waterproofing layer and top wearing course. The most important factors for this system are to meet satisfactory performance of the waterproofing layer and to develop appropriate construction technique for the thin drainage layer. The drainage layer was formulated with porous asphalt mixtures designed for the max aggregate size of 10 mm, and was validated through various physical and mechanical laboratory tests to confirm its performance characteristics. For the waterproofing layer, methyl methacrylate (MMA) – type material was introduced, and a series of mechanical tests were performed to estimate the applicability of the MMA material for waterproofing. It was observed from the tests that the MMA material satisfied all specification requirements. In addition, to evaluate the field performance of the new drainage system, a field study was conducted on a real bridge. Field performance observations on both the waterproofing and pavement materials indicated that the new drainage system performs much better than traditional methods in draining water that has penetrated into pavement layers.