Farrokh Tarpoudi Baheri

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Tarpoudi Baheri

First Name

Farrokh

ORCID

0000-0002-5809-8915

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Publications 1 - 6 of 6

Dropwise condensation freezing and frosting on bituminous surfaces at subzero temperatures
Tarpoudi Baheri, Farrokh; Poulikakos, L.D.; Poulikakos, Dimos; et al. (2021)
Construction and Building Materials
Freezing of atmospheric water on bituminous construction and road surfaces is a recurring event during winter. However, droplet freezing on bitumen and passive inhibition methods are poorly understood. Here we investigate relative humidity and substrate cooling effects on condensation freezing on subzero temperature bituminous surfaces and find that droplet freezing is explosive, with rapid local heating. We explain the related physics and find that relative humidity and cooling rate can affect droplet sizes and freezing temperatures. We then rationally embed phase change material microcapsules in bitumen, harnessing their latent heat to significantly delay freezing, demonstrating a viable option for frost mitigation.
The effect of additives on water vapor condensation on bituminous surfaces
Tarpoudi Baheri, Farrokh; Rico Luengo, Miguel; Schutzius, Thomas Michael; et al. (2022)
Journal of Testing and Evaluation
Water condensation and freezing on asphalt roads can lead to slippery conditions, which are responsible for many winter accidents and have caused an overreliance on mostly environmentally damaging and pavement degrading deicing chemicals and salt, which requires active maintenance. Bitumen is a mechanically and chemically complex material mainly consisting of various hydrocarbon-based chemicals groups. Additionally, bitumen makes up approximately 5 wt.% of the asphalt concrete mixture because of its binder role and coating function of the aggregates, can control the bulk mechanical properties and surface properties of the asphalt mixture. Condensation as the first step and later freezing phenomena are investigated in this study and from ambient humidity toward understanding the fundamentals of icing on bituminous surfaces. Condensation experimental results show selective wettability of chemically and mechanically district bitumen surface domains. The effect of different bitumen modifiers of polyethylene terephthalate, polyamide (PA 66), polyacrylonitrile, and Sasobit wax at 1 wt.% were studied on condensation freezing and bitumen water affinity.
Bitumen surface microstructure evolution in subzero environments
Tarpoudi Baheri, Farrokh; Schutzius, Thomas Michael; Poulikakos, Dimos; et al. (2020)
Journal of Microscopy
Microstructure analysis and mechanical performance of crumb rubber modified asphalt concrete using the dry process
Rodriguez-Fernandez, Israel; Tarpoudi Baheri, Farrokh; Cavalli, Maria C.; et al. (2020)
Construction and Building Materials
Globally, the vast majority of waste tires are landfilled, with catastrophic ecological consequences and in particular, serious threats to human health (e.g. fire, pests and soil contamination). Because of the increasing environmental awareness, the use of crumb rubber modified asphalt has become an important recycling strategy for waste tires. The so-called crumb rubber (CR), which is the recycled rubber from tires, has become a common additive in hot mix asphalt mixture due to its improvement of the mechanical performances of asphalt mixtures. The purpose of this study is to investigate the effect of adding crumb rubber to asphalt mixtures using the dry process by relating mechanical performances with microstructural characterizations. It was possible to observe the influence of conditioning process (time during which the asphalt mixture is kept at a high temperature after mixing) on the mechanical performance of the mixtures that depend primarily on the properties of the crumb rubber used. Specifically, it is shown that the conditioning time has an influence on the Marshall test results as well as the viscosity measurements. By using the Environmental Scanning Electron Microscope (ESEM), the distribution of the crumb rubber within the mixture has been investigated. In particular, the distribution of the crumb rubber by changing the conditioning time is of interest. The results showed that crumb rubber is well dispersed in the asphalt mixture when the conditioning time is increased. The effect of crumb rubber on the microstructure using Atomic Force Microscopy-Infrared Spectroscopy (AFM-IR) indicated that the main chemical change takes place in the para domain and catana or the so-called bee structures diminish on the CR modified bitumen as a consequence of more conditioning time. (C) 2020 Elsevier Ltd. All rights reserved.
Ice adhesion behavior of heterogeneous bituminous surfaces
Tarpoudi Baheri, Farrokh; Poulikakos, Lily D.; Poulikakos, Dimos; et al. (2021)
Cold Regions Science and Technology
The phenomenon of icing, and the derived processes for its mitigation, are of great importance in many applications, ranging from transportation and energy to food and refrigeration. This phenomenon has been studied mostly with respect to its manifestation on rigid, homogeneous surfaces, with soft materials being the topic of more recent investigations. Although, icing often occurs on substrates that are chemically and mechanically heterogeneous, e.g., widely used asphalt concrete, which consists of rigid aggregates embedded in soft bitumen, to date, ice adhesion behavior on such substrates needs to be better understood. Here, we study ice adhesion stresses—the stresses necessary to remove ice—of ice blocks on heterogeneous materials, juxtaposing the behavior of the two main constituents of asphalt concrete, the rigid aggregates (modeled by Macor®) and bitumen, to the behavior of bitumen-Macor® composites. We show that the ice adhesion shear stress on Macor® is almost twice as large as that on bitumen, whereas the ice adhesion normal stress and the normal and shear components of composite stress are in a similar range. We synthesize composite substrates that consist of bitumen stripes on Macor® and find that increasing bitumen width leads to lower ice adhesion stress, while the stripe direction with respect to the applied force direction has a minor effect. Based on our findings, we then coat the most ice-adhesive component (Macor®) with a thin superhydrophobic coating and show that this can reduce ice adhesion stress on the heterogeneous substrates. We also find that for ice formed half on bitumen and half on Macor®, if Macor® is first and bitumen second with respect to the applied force direction (material order), then the measured ice adhesion stress is less compared to the reverse case in material order.
On the Behaviour of Bituminous Surfaces at Subzero Temperatures: Condensation-Frosting and Icing
Tarpoudi Baheri, Farrokh (2021)

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Farrokh Tarpoudi Baheri

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