Browsing by Author "Lee, KWW"

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    Evaluation of warm mix asphalt with reclaimed asphalt pavement in rhode island
    (Springer, 2021) Shrestha, N; Lee, KWW; Veyera, G; Pasindu, HR; Bandara, S; Mampearachchi, WK; Fwa, TF
    The potential for using Warm Mix Asphalt (WMA) in reclaimed asphalt pavement (RAP) is becoming more interesting topic nowadays due to economic and environmental benefits. WMA technology allows reductions in production and compaction temperatures guaranteeing relevant environmental cost saving benefits. The objectives of the present study were to investigate and evaluate the performance of a typical additive in WMA pavement with RAP on rutting, fatigue cracking and thermal cracking resistance, which was used on Rhode Island (RI) Route 102. The asphalt binder was tested at different dosages of WMA additive using Dynamic Shear Rheometer (DSR), Rolling Thin Film Oven (RTFO), Pressure Aging Vessel (PAV), Multiple Stress Creep Recovery (MSCR), and Bending Beam Rheometer (BBR). It was found that 0.70% additive would lessen pavement damage in case of rutting, fatigue cracking and thermal cracking. After that, twoHMAspecimens, with and without RAP and two WMA specimen with and without RAP were prepared using Superpave Gyratory Compactor (SGC). These specimens were tested with the AsphaltMixture Performance Tester (AMPT) and developed master curves for each specimen. It was observed that WMA mixtures with RAP, could perform better in fatigue resistance but expected to have poor rutting performance than HMA and HMA-RAP. This study indicates that addition of WMA additives performs better in fatigue resistance.
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    item: Conference-Full-text
    Solar energy harvesting and pavement sensing
    (Springer, 2021) Lee, KWW; Greenfield, M; DeCotis, A; Lapierre, K; Pasindu, HR; Bandara, S; Mampearachchi, WK; Fwa, TF
    An attemptwas made to generate the required voltage in asphalt pavement to operate roadway sensors utilizing a temperature difference between two thermoelectric generators (TEGs). To enable output voltage by the TEGs below the asphalt surface layer, the harvester was installed with the copper plate 25 mm (1 in.) below the top surface layer. The copper plate is heated from the sun’s rays penetrating the asphalt surface layer and transferring the energy into the harvester system. The power generated from the TEGs allows temperature difference readings, as well as maximum power output voltage. Optimizing the harvester for efficiency and sustainability were top priorities. Once the copper plate receives the required voltage from the heat generation, the Arduino can be turned on. To communicate with the Arduino board in the current set-up, a USB cord gets plugged into the Arduino with the other end into the computer. The software program Arduino should then be opened on the computer to read data from the apparatus. An SD card or Bluetooth receiver was implemented into the solar harvester unit. This allows data for retrieval to be stored without an external power source (i.e., computer), allowing the harvester to operate freely. The strain transducer was installed into the asphalt surface layer for strain monitoring of the roadway. The SD card/USB would be able to store the information from the pavement strain transducer. Data retrieval would be achieved simply by unplugging the card from the harvester unit and uploading it to a computer.