Analysis of Aggregate Types with Micro-texture and Macro-texture Characteristics of Asphalt Mixture in Indonesia (original) (raw)
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The greatest emphasis in pavement performance has been done in structural design components. However, the pavement friction is also important and is one of the factors that determining pavement safety. The wet skidding crashes are largely reduced when friction between a vehicle tire and pavement is high. Skid resistance and texture are important safety characteristics which need to be considered when pavement mixes are tested in laboratory. The objective of this study was to evaluate the skidding based on macrotexture and microtexture used in the International Friction Index (IFI). This study was conducted in asphalt mixtures compacted slab produced in laboratory. Two different mixtures grading (dense and gap) were produced using conventional asphalt and asphalt rubber. The characterization of the macrotexture and microtexture of asphalt pavements surfaces was obtained by the following tests: (i) British pendulum; (ii) Volumetric Method. IFI values were calculated by the pair of the parameters Sp and F60. The results showed that the mixture with gap grading had higher texture in comparison of mixtures with a dense grade gradation. The asphalt rubber mixtures improved the skid resistance compared to conventional mixtures.
Predicting Asphalt Mixture Skid Resistance Based on Aggregate Characteristics
2009
The objective of this research project was to develop a method to determine the skid resistance of an asphalt mixture based on aggregate characteristics and gradation. Asphalt mixture slabs with different combinations of aggregate sources and mixture designs were fabricated in the laboratory, and their skid resistance was measured after different polishing intervals. The wheel-polishing device developed by the National Center for Asphalt Technology (NCAT) was used for polishing the slabs. Frictional characteristics of each slab were measured by sand patch method, British Pendulum, Dynamic Friction Tester (DFT), and Circular Texture Meter (CTMeter). Aggregates were characterized using a number of conventional test methods, and aggregate texture was measured using the Aggregate Imaging System (AIMS) after different polishing intervals in the Micro-Deval device. Petrographic analyses were performed using thin sections made with aggregates from each of these sources. Petrographic analyses provided the mineralogical composition of each source. The aggregate gradation was quantified by fitting the cumulative Weibull distribution function to the gradation curve. This function allows describing the gradation by using only two parameters. The results of the analysis confirmed a strong relationship between mix frictional properties and aggregate properties. The main aggregate properties affecting the mix skid resistance were Polish Stone Value, texture change before and after Micro-Deval measured by AIMS, terminal texture after Micro-Deval measured by AIMS, and coarse aggregate acid insolubility value. The analysis has led to the development of a model for the International Friction Index (IFI) of asphalt mixtures as a function of polishing cycles. The parameters of this model were determined as functions of (a) initial and terminal aggregate texture measured using AIMS, (b) rate of change in aggregate texture measured using AIMS after different polishing intervals, and the (c) Weibull distribution parameters describing aggregate gradation. This model allows estimating the frictional characteristics of an asphalt mixture during the mixture design stage.
Effect of Asphalt Mix Properties on Surface Texture: An Experimental Study
Applied Mechanics and Materials, 2013
Pavement surface characteristics play an important role in accident occurring, especially in wet conditions: the optimization of surface performance starting from hot mix asphalt (HMA) design phases is a fundamental requirement in road construction techniques. Although such relevance, the prediction of surface properties based on HMA composition and construction still calls for further research. Indeed, there is not a clear framework for a mix design oriented to surface properties. In the light of the abovementioned facts authors' efforts were focused into the analysis of the most significant factors influencing pavement surface macrotexture, by analyzing the main variables of existing macrotexture prediction models. Many experimental mixes were designed and produced. Some statistical correlations between macrotexture data and mixes grading and volumetric properties were also carried out. Outcomes of this study are expected to benefit both practitioners and researchers.
NCHRP-IDEA Program Project Final Report, 2007
This Innovations Deserving Exploratory Analysis (IDEA) project conducted a detailed analysis of aggregate texture and its relationship to pavement skid resistance. A new method was developed for the evaluation of aggregate resistance to polishing. This method relies on the Micro-Deval test as the mechanism for polishing aggregates and the Aggregate Imaging System (AIMS) for quantifying the change in texture due to polishing. Test results showed that the Micro-Deval test is an effective method for polishing aggregates within a short time. Also, the AIMS texture analysis is able to rapidly and accurately quantify the influence of polishing on texture. The verification of the new method was achieved through measuring the skid resistance of pavements constructed using three different aggregate sources and three different aggregate gradations. The skid resistance was found to be related not only to average aggregate texture, but also to the texture distribution within an aggregate sample...
2010
This report documents the findings from the research that was carried out as part of Phase II of TxDOT Project 0-5627. The research included measurements and analysis of mechanical and physical properties of aggregates used in surface mixes in the state of Texas. These properties were aggregate shape characteristics measured using the Aggregate Imaging System (AIMS), British Pendulum value, coarse aggregate acid insolubility, Los Angeles weight loss, Micro-Deval weight loss, and Magnesium sulfate weight loss. In addition, a database of field skid number measurements that were collected over a number of years using the skid trailer was developed. The Dynamic Friction Tester (DFT) and Circular Texture Meter (CTMeter) were used to measure friction and texture, respectively, of selected asphalt pavement sections. These data and measurements were used to carry out comprehensive statistical analyses of the influence of aggregate properties and mixture design on skid resistance value and i...
Journal of Rehabilitation in Civil Engineering, 2020
Pavement surface texture and its skid resistance are two key safety parameters of highways, which both are influenced by pavement characteristics. In the present study, a newly constructed asphalt pavement (Qom-Garmsar freeway) in Iran is examined. The goal is to inspect the relation between skid resistance and pavement texture in order to asphalt content changes in Hot Mix Asphalt. Mean Texture Depth (MTD) and British Pendulum Number (BPN) are being applied to quantify pavement texture and skid resistance, respectively. The results show that the asphalt content has a significant effect on MTD and consequently, BPN in loaded pavements, as well as non-loaded pavements. The result revealed that the lowest BPN value obtained, when the asphalt content is about the optimum value. Moreover, it is demonstrated that using asphalt contents less and more than the optimum value, results in BPN improvement. Asphalt content increasing, around optimum value, leads to MTD decrease. The results als...
Asphalt pavements surface texture and skid resistance — exploring the reality
Canadian Journal of Civil Engineering, 2012
Wet pavement skidding due to inadequate surface texture or friction contributes to 20% to 35% of all wet weather crashes. Many of the past studies of pavement surface texture and friction have deficiency in selecting the model forms or variables and interpreting the models and (or) the findings or have recommended further investigation. These pose a challenge for the highway agencies in selecting the appropriate surface layer and (or) measuring tools. This study was undertaken to re-examine some of the pavement surface texture and skid resistance related issues and aid the highway agencies in this area. Pavement surface texture and skid resistance aspects were carefully examined using the data collected from nine asphalt concrete (AC) surfaces. Pavement surface texture was measured using the sand patch method and a high speed texture laser. Skid resistance was measured using a British Pendulum and a skid trailer. The analysis has reinstated that aggregate quality is the predominant factor for AC surface skid resistance. Both texture depth and ribbed tire skid resistance was shown to increase with an increase in coarse aggregate (CA) content proving their interdependency. Neither the voids in mineral aggregate (VMA) or air voids (AV) contents showed a meaningful or statistically significant correlation with the surface texture or skid resistance. Fairly good correlations were found among the British Pendulum number (BPN), ribbed tire skid number (SN) and mean texture depth (MTD) rejecting the hypothesis that BPN is a measure of only surface microtexture and ribbed tire skid number is insensitive to surface texture.
— Stone Mastic Asphalt (SMA) mixtures rely on stone-to-stone contacts among particles to resist applied forces, and permanent deformation. Aggregates in SMA should resist degradation (fracture and abrasion) under high stresses at the contact points. Current practices for asphalt mix design and acceptance testing rely on volumetric properties. Vital to the calculation of mix volumetric properties are specific gravity measurements of the mixture and the aggregate in the mixture. For the Motorways wearing course,SMA stone grid must fulfil the mineralogical-petrographic condition to be on rock of igneous and/or metamorphic origin but of silicate composition, specific weight and LA method on resistance to fragmentation. During the construction of the Kosovo motorway for wearing course was used the SMA as asphaltlayer for providing longer lifetime to the road construction. The super-pave mix design for SMA wearing course has been composed considering the available stone with high mineralogical and petrographic composition. The stone used for the wearing course on this motorway has resistance to crushing of LA =18 which is below the standard criteria for heavy traffic roads and motorways wearing courses. Thespecific weight of used stone was 3100 kg/m3which is about 15% heavier than standard weight. For this specific stone were prepared special super-pave design mix with binder content 4.5% which was well below than typical SMA composition of 6.0−7.0% binder rather of mixture was 3100 kg/m 3. In this paperwork it is described the design mix of SMA composed with relatively high specific weight and their impacts on asphalt mix design properties used in Kosovo Motorway.
The effect of aggregate shape properties such as angularity, texture, sphericity, roundness, flat and elongation on the performance of asphalt mixes have not been thoroughly investigated using direct measurement techniques. This is partly because aggregates do not have regular shapes, and it is a daunting task to accurately determine these properties. In this paper, three types of aggregates are used to produce asphalt mixes in order to study the effect of coarse aggregate shape properties on the permanent deformation. A modern three-dimensional (3-D) laser scanning device available at the Council for Scientific and Industrial Research (CSIR) in South Africa was used to directly obtained shape properties of the aggregates. Permanent deformation tests were conducted in the laboratory on three different mixes produced from the aggregates to compare performance. It was found that the three asphalt mixes have different resistance to permanent formation. The aggregates with high surface texture and angularity improve resistance to permanent deformation of the asphalt mix when compared with those with more rounded or spherical shapes.
Evaluation of the Effect of Aggregates Angularity on the Surface Properties of Hot MIX Asphalt
2017
One of the most important properties of flexible pavements is the surface texture. The texture of the pavement surface and is ability to resist the polishing effect of traffic is of prime importance in providing skidding resistance. Pavement surface macrotexture greatly contributes to tire–pavement skid resistance which has a direct effect on traffic operation and safety particularly at high speeds. Doubtless, there exists a close relationship between the surface texture and the angularity characteristics of the aggregates whitin the pavement system. This paper describes the evaluation of the angularity characteristics of the aggregates crushed with different types of crushers, and their impact on the surface properties of the pavements such as texture and surface friction. For this purpose, limestone aggregates were prepared using impact, jaw, and roll crushers. Following the determination of the angularity characteristics of the aggregate using ASTM C1252 involving two different t...