Papers by Ahmed Hemida, PhD, MSc, A.M.ASCE, MIAAM
Journal of Materials in Civil Engineering, American Society of Civil Engineers (ASCE), 2023
Guayule resin was investigated through mixture to assess its role in the field performance. For p... more Guayule resin was investigated through mixture to assess its role in the field performance. For performance comparisons, conven- tional asphalt, neat guayule, asphalt–rubber–guayule, and guayule–rubber binders were implied. Field-simulated lab mixtures were made to investigate the major distresses. Modified Lottman, rut, semicircular bending, and disk-shaped compact tension tests were used to assess stripping, rutting, fatigue, and thermal cracking resistances. Stripping and rutting susceptibilities were also assessed by Hamburg wheel- tracking test. The outcomes disclosed that when the modified Lottman test was used, guayule containing a 7% air content was more sus- ceptible to stripping than that containing a 3.5% air content, resulting in tensile strength ratios of 40% and 71%, respectively. All investigated mixtures did not reach out the stripping inflection point under the Hamburg wheel-tracking criteria. Asphalt offered the worst Hamburg rut depth, which was 3.2 mm after 20,000 passes. Guayule-based mixtures perfectly resisted rutting as proven by the rut test. Guayule offered the worst rut depth of 6.3 mm, indicating a great rutting resistance. The guayule-based mixture had a high fracture toughness at intermediate temperatures. Guayule and guayule–rubber mixtures offered a critical strain energy release rate of 0.65–0.69 kJ=m2 compared to 0.46 kJ=m2 for asphalt. They, however, tended to possess low thermal fracture resistance (less than the threshold fracture energy, 400 J=m2). Conversely, a blend of 62.5% asphalt, 12.5% rubber, and 25% guayule offered 591 J=m2 at its performance grade low temperature (−16°C) and 409 J=m2 at −22°C compared to 429 J=m2 for asphalt at the later temperature, which represented the performance-grade low temperature of asphalt.
Review of Lightweight Deflectometer (LWD).
Journal of Cleaner Production, 2021
Asphalt cement will not last for a long time as the world encounters a diminishment in the crude ... more Asphalt cement will not last for a long time as the world encounters a diminishment in the crude oil. For sustainable, flexible pavement development, new resources can provide a contribution to replace it partially or entirely. In this study, asphalt was partially and entirely replaced by guayule resin as a bioresource byproduct, extracted during the guayule natural rubber production. Crumb rubber modifier (CRM) was used as an asphalt enhancer. The Superpave grading system was followed at high, intermediate, and low temperatures to evaluate such innovative binder for rutting, fatigue, and thermal cracking, respectively, in addition to viscosity. Therefore, the original, short-term aging and long-term aging were simulated using tank, rolling thin film oven, and pressure aging vessel materials. Additionally, component analysis using Fourier-transform infrared spectroscopy was provided to link the rheological properties with the chemical changes. Outcomes showed a relatively much lower viscosity of guayule in the same high-temperature asphalt grade indicating savings in plant energy consumption and reduced environmental emissions. CRM enhanced guayule, but not as much as asphalt, proven by polymeric component migration through liquid binder. This enhancement was reflected in the rheological performance besides other factors. As-received guayule seems to have high oxygen content proven by strong absorption peak intensities of oxidative bonds (e.g., Carbonyl and sulfoxide). Such pre-oxidation was negatively reflected in the intermediate-and lowtemperature performance of guayule and guayule-based binders. However, the investigated guayule had potential to compensate for asphalt replacement in the presence of CRM by 23-42% by weight of blend.
ABSTRACT This study is based on the proposed development corridor project by Dr. Farouk El-Baz wh... more ABSTRACT This study is based on the proposed development corridor project by Dr. Farouk El-Baz which attempt to expand the developed region westward throughout the Valley of River Nile. The aim of the current research is to investigate the impact of such a major super highway on the general movement of vehicle traffic in Egypt especially in the North – South direction. A Geographic Information System (GIS) Approach is selected for its suitability for such a problem at hand. Firstly, the selected alignment of the proposed developed corridor is digitized, and linked to the overall digitized national highway network of Egypt. The digitized process included the twelve branches highways throughout the River Nile Valley. The Scenario of With / Without Development Corridor is adopted to illustrate the impact of the project on different proposed expected journey linking Egypt between North regions [major harbors] and south regions [potential for development projects]. Also, the degree of development of the proposed super highway is considered in the study through varying design speed. The impact of the proposed project is presented in details on the Traveled Distance / Travelled time plot for different suggested Origin – Destination trips.
In this report, a summary of hands-on experience will be presented regarding the hot mix asphalt ... more In this report, a summary of hands-on experience will be presented regarding the hot mix asphalt (HMA) preparation by Marshall method: Mixing, Compaction, and Stability and Flow.
This research looks at a partial replacement of asphalt-rubber (AR) binder by Guayule Resin (BGR)... more This research looks at a partial replacement of asphalt-rubber (AR) binder by Guayule Resin (BGR), at least to compensate the original asphalt (AC) high-temperature performance. In particular, storage stability and phase separation (essential parameters affected by modified-binder storage) were addressed in this regard. AR-BGRs were compared to their corresponding ARs, to judge the BGR contribution. The binder whole matrix (WM) storage stability relied on the viscosity, density, and CRM dissolution. Measurements related to these parameters and storage stability were taken. Thermogravimetric analysis (TGA) was used to analyze CRM dissolution. Comparisons between WMs vs. liquid phases (LPs) were established as could show the variation between their storage stability and LP separation. Rheological analysis by master curves was provided for top and bottom fractions of WMs and LPs to judge the effect of remaining CRM (residue) and LP separation on the behavior. TGA and Fourier-transform infrared spectroscopy (FTIR) were utilized to verify the LP separation analysis. Outcomes showed that AR-BGR WMs yielded lower storage stability compared to ARs. The authors see that the viscosity difference between AC and BGR was the crucial reason. Nevertheless, perfect storage stability and no LP separation were observed with either AR-BGRs or ARs as proven by rheological analysis and verified by TGA and FTIR analyses for selected binder fractions. Accordingly, the study claimed BGR (PG52) could replace a portion of AR on the LP scale to at least compensate the original asphalt (PG64) performance (e.g., LP of 75%AR (including 20%CRM by wt. of AC) plus 25%BGR).
This paper mainly presents a qualitative review on to what extent the bio-oil has the potential t... more This paper mainly presents a qualitative review on to what extent the bio-oil has the potential to replace asphalt binder for a sustainable, flexible pavement industry. The current research comprises reviews on the rheological characterization of pure bio-oils and bio-oil modified binders (bio-binders) investigated in the literature. The literature showed that several sources of bio-oils have the potential to contribute to the flexible pavement industry. This research mainly discusses the high-temperature properties, especially viscosity for the construction process (mixing and compaction) and viscoelasticity for the elevated temperature of in-service roads. This review paper encourages orientation towards these kinds of renewable sources of binders in the flexible pavement industry regarding economics, sustainability, and environmental aspects. All reviewed bio-oils in this work, which are waste wood, switchgrass, and waste cooking oil (WCO), could provide a partial or entire subst...
Asphalt cement will not last for a long time as the world encounters a diminishment in the crude ... more Asphalt cement will not last for a long time as the world encounters a diminishment in the crude oil. For sustainable, flexible pavement development, new resources can provide a contribution to replace it partially or entirely. In this study, asphalt was partially and entirely replaced by guayule resin as a bioresource by-product, extracted during the guayule natural rubber production. Crumb rubber modifier (CRM) was used as an asphalt enhancer. The Superpave grading system was followed at high, intermediate, and low temperatures to evaluate such innovative binder for rutting, fatigue, and thermal cracking, respectively, in addition to viscosity. Therefore, the original, short-term aging and long-term aging were simulated using tank, rolling thin film oven, and pressure aging vessel materials. Additionally, component analysis using Fourier-transform infrared spectroscopy was provided to link the rheological properties with the chemical changes. Outcomes showed a relatively much lowe...
Resources, Conservation and Recycling, 2021
Abstract This research seeks to interpret the component analysis of an innovative bio-asphalt bin... more Abstract This research seeks to interpret the component analysis of an innovative bio-asphalt binder using guayule resin at high concentrations and crumb rubber modifier (CRM). Such asphalt modification aims to minimize the dependency on base asphalt and provide new solutions concerning sustainable, flexible pavement industry. Guayule resin is a promising bioresource for asphalt replacement. The provided interpretation could help in understanding the asphalt-rubber-guayule interaction mechanism. Fourier transform infrared spectroscopy (FTIR), supported by thermo-gravimetric analysis (TGA), was used to investigate the component analyses of guayule resin composition, asphalt-guayule interaction, and asphalt-rubber-guayule interaction, followed by oxidative aging behavior. Additionally, the rheological properties at high and intermediate temperatures were provided to link the microscale properties with the final product performance. The study clarified the distinct carbon and hydrogen compositional elements of guayule resin. Asphalt and guayule resin had similarities in component composition and rheological behavior with temperature susceptibility. Asphalt-guayule interaction yielded a physical blending, with no chemical reaction. Rubber seems to dissolve in both asphalt-rubber and asphalt-rubber-guayule interactions evenly. Devulcanization occurred, resulting in a partial migration of CRM polymeric components to the liquid binder. This was reflected in the enhanced performance of asphalt-rubber-guayule blends at high temperatures. However, due to the strong oxidation bonding chains attributed to guayule resin, the oxidative aging negatively affected the guayule-based binder performance reflected on the intermediate temperature performance. The mix performance was initiated with the guayule-based binder's successful performance against rutting susceptibility, comparative to the base asphalt.
Advances in Civil Engineering Materials, 2020
Crumb rubber modifier (CRM) is considered one of the most commonly used modifiers that enhances t... more Crumb rubber modifier (CRM) is considered one of the most commonly used modifiers that enhances the rheological properties of asphalt binders. Optimizing the interaction process between CRM and asphalt binder to enhance the asphalt binder’s elasticity without additional additives is the main purpose of the article. Rheological properties were measured in this article for neat asphalt and crumb rubber modified asphalt (CRMA) binders. Two sets of interactions were selected. In the first interaction set, one interaction temperature (190°C), one interaction speed (3,000 rpm), and different interaction times (0.5, 1, 2, 4, and 8 h) were used. The used CRM percentage was 10 % by weight of the neat asphalt binder. Two sources of asphalt binder, one source and different percentages of CRM, one interaction temperature (190°C), one interaction speed (3,000 rpm), and different interaction times were selected for the second interaction set. This set was designated to confirm the rheological properties obtained for the first set. Thermogravimetric analysis (TGA) was performed on CRM particles before and after their interaction with asphalt binder after different interaction times. The CRMA binders that interacted for the entire 8-h interaction times had significantly enhanced properties, especially the elasticity, as compared to the neat asphalt binder. The 8-h interaction time showed the highest CRM dissolution percentage by dissolution and TGA testing. At this interaction time, more CRM components were released into the asphalt binder liquid phase, which was detected by observing Fourier-transform infrared peaks at 966 cm−1 for polypropylene and 699 cm−1 for polystyrene.
Construction and Building Materials, 2020
h i g h l i g h t s Separation tendency was investigated to assess the innovative binder stabilit... more h i g h l i g h t s Separation tendency was investigated to assess the innovative binder stability. Asphalt-rubber-guayule binders were compared to base asphalt and asphalt rubber. The study concluded (almost) no liquid phase separation for all designated binders. Recommended not to store such a designated binder as most rubber settled down. Further recommendations for the significant storage instability were presented.
Recycling, 2019
This study seeks to find the influence of replacing a portion of the asphalt–rubber binder with t... more This study seeks to find the influence of replacing a portion of the asphalt–rubber binder with the bio-based material “guayule resin.” This replacement could be beneficial in terms of sustainability, economics, and environmental concerns related to the asphalt industry. Nine asphalt–rubber–guayule binders were investigated to find their rheological properties. Consecutively, the study proceeded with five selected binders being compared to the original asphalt (PG64-22). Investigations underwent whole matrices (crumb rubber modifier (CRM) residue included) and liquid phases (CRM residue extracted). Additionally, these properties were partially sought for their corresponding asphalt–rubber binders to compare and judge the contribution of the guayule resin. Likewise, a thermo-gravimetric analysis was done for the guayule resin to recognize its moisture and composition complexity. Such an analysis was also done for the as-received CRM and some extracted CRMs to determine the release an...
Literature revealed the potential of using guayule resin for asphalt cement replacement from the ... more Literature revealed the potential of using guayule resin for asphalt cement replacement from the binder’s perspective. However, monitoring guayule resin through binder-aggregate mixture could disclose its performance through field. In this study, designated binders were employed to investigate the applicability of such an innovative replacer through mixture, which were neat asphalt and guayule-based binders (neat guayule, asphalt-rubber-guayule, guayule-rubber binders). Consecutively, field-simulated lab mixtures were prepared to investigate the major distresses. Moisture damage, rutting, fatigue cracking, and thermal cracking resistances were investigated using the modified Lottman (TSR) test, rut test by asphalt pavement analyzer (APA), semi-circular bending (SCB) test, and disk-shaped compact tension (DCT) test, respectively. Additionally, the Hamburg wheel-tracking (HWT) test was employed to evaluate moisture susceptibility and rutting resistance. Outcomes revealed that the neat...
Review of Lightweight Deflectometer (LWD).
International Journal of Engineering Research and, 2018
This study denotes a threshold to utilize Guayule Resin as a new bio-based binder or asphalt ceme... more This study denotes a threshold to utilize Guayule Resin as a new bio-based binder or asphalt cement (AC) proportion, both with/out crumb rubber modifier (CRM), regarding solutions for environment, cost, and sustainability aspects. Via this research, 15 designated binders will be presented, all of them were tested as unaged and RTFO, whereas eight binders proceeded with PAV. Superpave was utilized to study their physical properties. Viscosity was examined upon some guayule-based binders with/out CRM, getting 114cP (at 135°C) for BGR, increased to about 3 times with 10%CRM (by weight of liquid binder) and about 7-8 times with 20%CRM. Comparisons among binders will be depicted regarding six categories (Neat AC, Neat BGR, AC+BGR, BGR+CRM, AC+CRM, and AC+BGR+CRM). This study initiates a perspective to judge designated binders and get benefit upon performance required. That’s why the study reported outcomes regarding the effectiveness of the binder’s stiffness, elasticity and performance....
Transportation Engineering
Preprints, MDPI, 2021
Literature revealed the potential of using guayule resin for asphalt cement replacement from the ... more Literature revealed the potential of using guayule resin for asphalt cement replacement from the binder's perspective. However, monitoring guayule resin through binder-aggregate mixture could disclose its performance through field. In this study, designated binders were employed to investigate the applicability of such an innovative replacer through mixture, which were neat asphalt and guayule-based binders (neat guayule, asphalt-rubber-guayule, guayule-rubber binders). Consecutively, field-simulated lab mixtures were prepared to investigate the major distresses. Moisture damage, rutting, fatigue cracking, and thermal cracking resistances were investigated using the modified Lottman (TSR) test, rut test by asphalt pavement analyzer (APA), semi-circular bending (SCB) test, and disk-shaped compact tension (DCT) test, respectively. Additionally, the Hamburg wheel-tracking (HWT) test was employed to evaluate moisture susceptibility and rutting resistance. Outcomes revealed that the neat guayule was susceptible to moisture damage at a 7% air content (Va) when the TSR test was employed. In contrast, all investigated mixtures yielded perfect performances against moisture susceptibility under the HWT test. Guayule-based mixtures perfectly resisted rutting, as analyzed by the rut test and HWT test. Generally, changing parameters (e.g., Va, rubber addition, and partial asphalt replacement by guayule and rubber) enhanced the guayule-based mixture resistance to rutting and moisture damage resulting in acceptable performances. Guayule-based mixture had a high fracture toughness at low temperatures, hence fatigue fracture resistance at intermediate temperatures. Neat guayule mixture with or without rubber addition did not entirely resist thermal fracture. However, partial asphalt replacement by guayule and rubber resisted the thermal fracture to a great extent.
Journal of Cleaner Production, Elsevier, 2021
Novel resources can contribute to replacing asphalt with sustainable, flexible pavement options. ... more Novel resources can contribute to replacing asphalt with sustainable, flexible pavement options. In this study, asphalt was replaced by guayule resin as a bioresource by-product extracted during guayule natural rubber production. Crumb rubber modifier (CRM) was used as an asphalt enhancer. According to the Superpave criteria, the designated binders were exposed to tests covering the construction process (mixing and compaction requirements), rutting, fatigue, and thermal cracking resistances through viscosity, high-, intermediate-, and low-temperature measurements, respectively. The original, short-term aging, and long-term aging conditions were simulated using tank, rolling thin film oven, and pressure aging vessel materials, respectively. Additionally, component analysis using Fourier-transform infrared spectroscopy was performed to link the rheological properties with the chemical changes. Outcomes showed a relatively lower viscosity for guayule resin than asphalt at the same high-temperature grade, thus indicating savings in plant energy consumption and environmental emissions. The CRM enhanced guayule, but not as much as asphalt, as proven by polymeric component migration through the liquid binder. This enhancement was reflected in the rheological performance in addition to other factors. The as-received guayule resin had a high oxygen content confirmed by strong absorption peak intensities of oxidative bonds (e.g., Carbonyl and sulfoxide). Such pre-oxidation was negatively reflected in the intermediate- and low-temperature performances of guayule resin and guayule-based binders. However, the investigated guayule resin compensated for asphalt replacement by 23–42% of the blend's weight.
Using the enclosed author link, it is accessible for the first 50 days (by August 16, 2021) to view and download. It will be for Elsevier subscribers thereafter.
Author Link: https://lnkd.in/grMrnuj
Resources Conservation and Recycling, Elsevier, 2021
This research seeks to interpret the component analysis of an innovative bio-asphalt binder using... more This research seeks to interpret the component analysis of an innovative bio-asphalt binder using guayule resin at high concentrations and crumb rubber modifier (CRM). Such asphalt modification aims to minimize the dependency on base asphalt and provide new solutions concerning sustainable, flexible pavement industry. Gua-yule resin is a promising bioresource for asphalt replacement. The provided interpretation could help in understanding the asphalt-rubber-guayule interaction mechanism. Fourier transform infrared spectroscopy (FTIR), supported by thermo-gravimetric analysis (TGA), was used to investigate the component analyses of guayule resin composition, asphalt-guayule interaction, and asphalt-rubber-guayule interaction, followed by oxidative aging behavior. Additionally, the rheological properties at high and intermediate temperatures were provided to link the microscale properties with the final product performance. The study clarified the distinct carbon and hydrogen compositional elements of guayule resin. Asphalt and guayule resin had similarities in component composition and rheological behavior with temperature susceptibility. Asphalt-guayule interaction yielded a physical blending, with no chemical reaction. Rubber seems to dissolve in both asphalt-rubber and asphalt-rubber-guayule interactions evenly. Devulcanization occurred, resulting in a partial migration of CRM polymeric components to the liquid binder. This was reflected in the enhanced performance of asphalt-rubber-guayule blends at high temperatures. However, due to the strong oxidation bonding chains attributed to guayule resin, the oxidative aging negatively affected the guayule-based binder performance reflected on the intermediate temperature performance. The mix performance was initiated with the guayule-based binder's successful performance against rutting susceptibility, comparative to the base asphalt.
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Papers by Ahmed Hemida, PhD, MSc, A.M.ASCE, MIAAM
Using the enclosed author link, it is accessible for the first 50 days (by August 16, 2021) to view and download. It will be for Elsevier subscribers thereafter.
Author Link: https://lnkd.in/grMrnuj
Using the enclosed author link, it is accessible for the first 50 days (by August 16, 2021) to view and download. It will be for Elsevier subscribers thereafter.
Author Link: https://lnkd.in/grMrnuj
1. Replace asphalt cement (AC) in the asphalt pavement industry at specific grades
(by itself or by adding an enhancer (e.g., crumb rubber modifier (CRM))?
2. Work as a new bio-based additive to AC or asphalt-rubber (AR)?