Entity

Time filter

Source Type

North Central, United States

Dare T.,Ray W Herrick Laboratories | Woldemariam W.,Purdue University | McDaniel R.,North Central Superpave Center | Olek J.,Purdue University | Bernhard R.,University of Notre Dame
Transportation Research Record | Year: 2012

Sound absorption measurements have been used as a simple, cost-effective way of assessing pavement noise properties in the laboratory. However, tire-pavement noise (TPN) is emitted close to the pavement at shallow angles of incidence between the tire and a roadside receiver. Absorption properties can be used to predict oblique incidence noise properties, provided that certain assumptions are met. Near-grazing-incidence predictions of noise vary widely, and the assumptions involved may not be applicable to porous asphalt pavements. A method of directly measuring near-grazing-incidence noise reduction of hot-mix asphalt pavements was designed. It was found that the results of the proposed test could not be predicted from absorption data alone except for dense-graded pavement. For porous or thin, gap-graded pavements, the near-grazing-incidence test gave additional useful information about the acoustic performance of the pavement samples. The test can be used to supplement absorption and other laboratory tests for more accurate predictions of TPN. Source


Behnood A.,Purdue University | Behnood A.,North Central Superpave Center | Olek J.,Purdue University | Glinicki M.A.,Polish Academy of Sciences
Construction and Building Materials | Year: 2015

Abstract The use of recycled aggregates in concrete is on the rise, driven by economic and environmental concerns. However, most of the existing models to predict the value of elastic modulus of concrete were developed for virgin aggregates and, as a result, they may often be inaccurate when applied to concrete made with recycled aggregate. In this study, the M5′ model tree algorithm was used to predict the elastic modulus of recycled aggregate concrete. The main advantages of the model tree algorithms are: (a) they output relatively simple mathematical models (formulas) and (b) are more convenient to develop and employ compared with other soft computing methods. To develop the model tree presented in this paper, over 450 data records were collected from internationally published literature. Error measures were used to compare the performance of the M5′ algorithm output to the output from other existing models. The results showed that the model developed using the M5′ algorithm has accuracy over 80 percent, which is well above the accuracy the other models. © 2015 Elsevier Ltd. Source


Kowalski K.J.,Warsaw University of Technology | Dare T.,Pennsylvania State University | Mcdaniel R.S.,North Central Superpave Center | Olek J.,Purdue University | Bernhard R.,University of Notre Dame
Archives of Civil Engineering | Year: 2013

Communication noise is classified as one of the pollutions for the current environment. Experimental techniques to measure tire-pavement noise generation from asphalt pavements in the laboratory have been limited. A series of experiments were conducted on six different asphalt mixtures to determine if Purdue University's Tire-Pavement Test Apparatus (TPTA) could be used to overcome these limitations. The procedure produced samples with low tire-pavement noise; however, the air void contents of the samples were higher than designed. Despite these difficulties, the sample preparation technique and the TPTA testing protocol were shown to offer an effective approach for quick laboratory assessment of tire-pavement noise characteristics of hot mix asphalt pavements at a substantially reduced cost compared to field testing. Source


Kowalski K.J.,Warsaw University of Technology | McDaniel R.S.,North Central Superpave Center | Olek J.,Purdue University | Shah A.,North Central Superpave Center
Journal of Testing and Evaluation | Year: 2011

The binder content of hot mix asphalt (HMA) is most commonly determined either by solvent extraction or ignition oven (IO) methods. Generally, the IO method has worked well with various HMA mixtures except those containing certain types of high mass loss (decomposing) aggregates, especially dolomite. For these aggregates, the high temperatures experienced during the ignition process initiate chemical changes within the aggregate particles, which result in variable mass losses. This, in turn, causes difficulties in calculating a consistent correction factor and determining a repeatable binder content. This paper presents a modified IO binder content determination method, which involves lowering the test temperature to 427°C and reducing the sample mass by half. In addition, only the bottom material basket of the typical IO test setup is used to avoid errors in the results due to temperature differentials that develop when, upon ignition, mixture from the lower basket starts heating the mixture in the upper basket. The proposed method was successfully verified by using six different plant-produced mixtures. Copyright © 2011 by ASTM International. Source

Discover hidden collaborations