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Use of additives and modifiers as an effective alternative to mitigate premature cracking of flexible pavements has been gaining popularity during the past three decades. Several studies have discussed the advantages and disadvantages of using various types of fibers in pavement industry. The objective of this study is to evaluate the impact of using Pulp Aramid Fiber (PAF) in Hot Mix Asphalt (HMA) in terms of mix design and performance. Aramid fibers or aromatic polyamide fibers were the first type of organic fibers found to have sufficient tensile strength and modulus to be used in advanced composites. Although studying the effect of additives on performance of HMA mixes has been the focus of several studies, the extent of work on the use of PAF in HMA mixes using a comprehensive methodology has been limited. A control mix and a PAF modified HMA mix were designed and evaluated with respect to their rutting resistance, fatigue cracking resistance, and low temperature cracking performance. The results indicate that mixes with PAF led to higher demand for bitumen content to achieve the same air void level as compared to the control mix. However, it was concluded that this additional binder content along with the presence of PAF resulted in an enhanced performance, especially with respect to fatigue cracking as well as improved ductility at cold temperatures. In spite of the additional binder content, the PAF modified mix exhibited satisfactory permanent deformation performance at high temperatures while considerably improving the fatigue and low temperature behavior of the mix. The results also indicate that PAF can delay cracking failure in long-term life of asphalt concrete mixes under repeated loading.
Saeed S. Saliani; Pejoohan Tavassoti; Hassan Baaj; Alan Carter. Characterization of asphalt mixtures produced with short Pulp Aramid fiber (PAF). Construction and Building Materials 2021, 280, 122554 .
AMA StyleSaeed S. Saliani, Pejoohan Tavassoti, Hassan Baaj, Alan Carter. Characterization of asphalt mixtures produced with short Pulp Aramid fiber (PAF). Construction and Building Materials. 2021; 280 ():122554.
Chicago/Turabian StyleSaeed S. Saliani; Pejoohan Tavassoti; Hassan Baaj; Alan Carter. 2021. "Characterization of asphalt mixtures produced with short Pulp Aramid fiber (PAF)." Construction and Building Materials 280, no. : 122554.
Hydraulic road binders (HRBs) are specially designed materials for pavement stabilisation. The objective of this research was to investigate the properties of several laboratory-blended HRBs constituted of reduced cement clinker content and different types of Supplementary Cementitious Materials (SCMs). Formulated HRBs were characterised chemically and physically in the form of paste and mortar. Laboratory results showed a distinct reduction of hydration temperature and drying shrinkage in HRBs. In addition, HRBs had different contents of hydration products compared to Portland cement. Moreover, HRB mortars containing up to 50% of slag could have similar strength compared to GU and GUL at 28 curing days and onwards. It was also indicated that slag had superior strength development effect compared to the other two SCMs. Furthermore, a statistical prediction was conducted on compressive and flexural strength of HRB mixes. Finally, a framework of HRB optimisation was proposed.
Sheng-Lin Wang; Hassan Baaj. Impact of supplementary cementitious materials on the hydration and strength properties of hydraulic road binders. Road Materials and Pavement Design 2021, 1 -26.
AMA StyleSheng-Lin Wang, Hassan Baaj. Impact of supplementary cementitious materials on the hydration and strength properties of hydraulic road binders. Road Materials and Pavement Design. 2021; ():1-26.
Chicago/Turabian StyleSheng-Lin Wang; Hassan Baaj. 2021. "Impact of supplementary cementitious materials on the hydration and strength properties of hydraulic road binders." Road Materials and Pavement Design , no. : 1-26.
Different temperature sensitivity parameters were introduced to address the temperature susceptibility of asphalt cement, all of which used a single number to define each particular material by assuming linearity in temperature sensitivity. The time-temperature superposition principle (TTS) has been used, under different circumstances, to understand the viscoelastic properties of asphalt materials. Various empirical relationships have been developed to explain the relationship between TTS shift factors and temperature. This research evaluated the suitability of such relationships to evaluate the temperature sensitivity of viscoelastic materials and found that the modified Arrhenius equation is more fundamentally appropriate for this purpose. Results of this study showed that the temperature sensitivity of rheological parameters (TSRP), introduced here, is sensitive to age hardening (for both asphalt cement and mix) and can be used to evaluate age hardening and changes in mix’s volumetric properties as well as investigating the effect of mix design properties.
Yashar Azimi Alamdary; Hassan Baaj. Time-Temperature Superposition of Asphalt Materials and Temperature Sensitivity of Rheological Parameters (TSRP). Canadian Journal of Civil Engineering 2020, 1 .
AMA StyleYashar Azimi Alamdary, Hassan Baaj. Time-Temperature Superposition of Asphalt Materials and Temperature Sensitivity of Rheological Parameters (TSRP). Canadian Journal of Civil Engineering. 2020; ():1.
Chicago/Turabian StyleYashar Azimi Alamdary; Hassan Baaj. 2020. "Time-Temperature Superposition of Asphalt Materials and Temperature Sensitivity of Rheological Parameters (TSRP)." Canadian Journal of Civil Engineering , no. : 1.
Fatigue is one of the most common modes of failure in both flexible and rigid pavements. Several studies have been conducted to study this phenomenon for pavement materials such as bituminous mixes, Portland cement concrete, and cement treated aggregates and soils. The fatigue behaviour of full-depth reclaimed pavement material treated with cementitious binders (FRPMC), however, has barely been studied. FRPMC are composed of reclaimed asphalt pavement (RAP) aggregates, granular base course/sub-base aggregate, fine grained soil particles and 3%–6% cementitious binders. As a result, FRPMC have different properties than bituminous mixes and Portland cement concrete. In this study, the fatigue behaviour of FRPMC was assessed using four-point bending test, which was conducted in strain-control mode. The objectives of the study were to assess the fatigue life range of FRPMC at different strain levels, identify the influence of various cementitious stabilizer on the fatigue life and investigate the response of FRPMC to cyclic loadings. Eight mixtures and forty-eight beam specimens were prepared for the study using the two types of reclaimed materials and four types of binders. The findings of the study indicated that the type of cementitious stabilizers used did not have significant effect on the fatigue life of FRPMC mixtures. It was also identified that FRPMC behaves as a quasi-brittle material while possessing some properties of viscoelastic materials.
Eskedil Melese; Hassan Baaj; Susan Tighe. Fatigue behaviour of reclaimed pavement materials treated with cementitious binders. Construction and Building Materials 2020, 249, 118565 .
AMA StyleEskedil Melese, Hassan Baaj, Susan Tighe. Fatigue behaviour of reclaimed pavement materials treated with cementitious binders. Construction and Building Materials. 2020; 249 ():118565.
Chicago/Turabian StyleEskedil Melese; Hassan Baaj; Susan Tighe. 2020. "Fatigue behaviour of reclaimed pavement materials treated with cementitious binders." Construction and Building Materials 249, no. : 118565.
Severe Canadian winter conditions and growing traffic volumes are vital factors resulting in a reduction of the service life of flexible pavements. Researchers and engineers strived to develop several additives to develop balanced asphalt mixers capable of resisting distresses that caused deterioration of flexible pavements in Canada. In this study, a critical literature review regarding the use of geopolymers and their application in construction materials is provided. Moreover, an experimental matrix of laboratory testing was conducted to study the rheological and microstructural properties of the PG 58-28 asphalt binder, with different percentages (0%, 3%, 6%, and 9%) of geopolymer. The effect of geopolymer-curing time on rheological properties was investigated. Rotational viscometer, dynamic shear rheometer (DSR), and environmental scanning electron microscopy (ESEM) imaging devices were used to compare the performance of control binder with a binder with different percentages of geopolymers. Results indicated that the increase in the geopolymer content and the curing time affect the rheological behavior of the asphalt binder by increasing its viscosity, complex shear modulus, and failure temperature. Samples with higher geopolymer percentage exhibited better performance in terms of rutting resistance. Moreover, an increase in the failure temperature of modified asphalt binder with 9% geopolymer is recorded as 8.58%, 14.2%, and 15.2% for curing times of 2, 7, and 14 days, respectively, compared with virgin asphalt. Furthermore, the nanoparticles appear to be well dispersed in the binder, and increasing the percentage of the geopolymer does not seem to affect the microstructure of the binder. Overall research conclusion is that geopolymer application resulted in a potential enhancement of some of the properties of the asphalt binder.
Abdulrahman Hamid; Hamed Alfaidi; Hassan Baaj; Mohab El-Hakim. Evaluating Fly Ash-Based Geopolymers as a Modifier for Asphalt Binders. Advances in Materials Science and Engineering 2020, 2020, 1 -11.
AMA StyleAbdulrahman Hamid, Hamed Alfaidi, Hassan Baaj, Mohab El-Hakim. Evaluating Fly Ash-Based Geopolymers as a Modifier for Asphalt Binders. Advances in Materials Science and Engineering. 2020; 2020 ():1-11.
Chicago/Turabian StyleAbdulrahman Hamid; Hamed Alfaidi; Hassan Baaj; Mohab El-Hakim. 2020. "Evaluating Fly Ash-Based Geopolymers as a Modifier for Asphalt Binders." Advances in Materials Science and Engineering 2020, no. : 1-11.
José Norambuena-Contreras; Lily Poulikakos; Hassan Baaj; Quantao Liu. Novel Bituminous Materials for Sustainable Pavements. Advances in Materials Science and Engineering 2020, 2020, 1 -2.
AMA StyleJosé Norambuena-Contreras, Lily Poulikakos, Hassan Baaj, Quantao Liu. Novel Bituminous Materials for Sustainable Pavements. Advances in Materials Science and Engineering. 2020; 2020 ():1-2.
Chicago/Turabian StyleJosé Norambuena-Contreras; Lily Poulikakos; Hassan Baaj; Quantao Liu. 2020. "Novel Bituminous Materials for Sustainable Pavements." Advances in Materials Science and Engineering 2020, no. : 1-2.
Portland cement has been widely used to improve the engineering performance of pavement materials. On the other hand, hydraulic road binder (HRB) is now a frequent option in Europe for the treatment of road base, and subbase, and earthworks. HRB contains high amounts of supplementary cementitious materials (SCMs) and by-products. HRB has the potential of reducing the amount of cement clinker thereby making it more cost effective and environmentally friendly. Moreover, the HRB treated materials also have improved workability due to its slower setting and hardening. The primary objective of this study is to investigate the chemical and physical properties of organic clayey subgrade materials treated by different HRBs. The paper first introduced a brief background for the development of hydraulic binders and their current applications for soil stabilisation. Then, it presented the results of laboratory testing for cement- and HRB- treated subgrade soils. Test results indicated that all the three subgrade soils named Dresden, Blenheim, and Niagara were fine-grained soils with substantial silt and cvnlay particles and organic matters. Cement and HRBs significantly improved soil’s engineering properties. The improvement included the change of soil’s environment from acidic to alkaline and prevent development of organics, the significant improved strength, durability, and resilient modulus. In addition, HRB-treated subgrade soils had lower sulfate included than cement-treated one that could reduce the risk of sulfate-induced problems. Among all HRB-treated materials, with abundant curing, the subgrade soils treated with the HRB composed of GUL and slag (HRB-4LS) had the highest UCS values, followed by the soil treated with HRB-4LF (composed of GUL and fly ash), and HRB-3S (GU and GGBFS). It should be noted as well that the soil types played an important role in the treatment. Soils with high plasticity, high organic matters had lower strength and modulus than less plastic and organic soils. Lastly, the differences of the soils could be visualised from the environmental scanning electron microscopy (ESEM) images. This research contributed to a tentative treatment of weak subgrade soil with locally blended HRBs. The results also proposed a potential solution for the treatment of weak subgrade soils at the top of the natural subgrade.
Sheng-Lin Wang; Hassan Baaj. Treatment of weak subgrade materials with cement and hydraulic road binder (HRB). Road Materials and Pavement Design 2020, 22, 1756 -1779.
AMA StyleSheng-Lin Wang, Hassan Baaj. Treatment of weak subgrade materials with cement and hydraulic road binder (HRB). Road Materials and Pavement Design. 2020; 22 (8):1756-1779.
Chicago/Turabian StyleSheng-Lin Wang; Hassan Baaj. 2020. "Treatment of weak subgrade materials with cement and hydraulic road binder (HRB)." Road Materials and Pavement Design 22, no. 8: 1756-1779.
Utilizing recycled asphalt pavements (RAP) in pavement construction is known as a sustainable approach with significant economic and environmental benefits. While studying the effect of high RAP contents on the performance of hot mix asphalt (HMA) mixes has been the focus of several research projects, limited work has been done on studying the effect of RAP fraction and particle size on the overall performance of high RAP mixes produced solely with either coarse or fine RAP particles. To this end, three mixes including a conventional control mix with no RAP, a fine RAP mix (FRM) made with 35% percent fine RAP, and a coarse RAP mix (CRM) prepared with 54% of coarse RAP were designed and investigated in this study. These mixes were evaluated with respect to their rutting resistance, fatigue cracking resistance, and low temperature cracking performance. The results indicate that although the CRM had a higher RAP content, it exhibited better or at least the same performance than the FRM. The thermal stress restrained specimen testing (TSRST) results showed that the control mix performed slightly better than the CRM, while the FRM performance was adversely affected with respect to the transition temperature midpoint and the maximum tensile stress temperature. Both of the RAP incorporated mixes exhibited better rutting resistance than the control mix. With regard to fatigue cracking, the CRM performed better than the FRM. It can be concluded that the RAP particle size has a considerable effect on its contribution to the total binder content, the aggregate skeleton of the mix, and ultimately the performance of the mix. In spite of the higher RAP content in the CRM versus FRM, the satisfactory performance observed for the CRM mix indicates a great potential in producing high RAP content mixes through optimizing the RAP particle size and content. The results also suggest that the black curve gradation assumption is not representative of the actual RAP particles contribution in a high RAP mix.
S. Saeed Saliani; Alan Carter; Hassan Baaj; Pejoohan Tavassoti. Characterization of Asphalt Mixtures Produced with Coarse and Fine Recycled Asphalt Particles. Infrastructures 2019, 4, 67 .
AMA StyleS. Saeed Saliani, Alan Carter, Hassan Baaj, Pejoohan Tavassoti. Characterization of Asphalt Mixtures Produced with Coarse and Fine Recycled Asphalt Particles. Infrastructures. 2019; 4 (4):67.
Chicago/Turabian StyleS. Saeed Saliani; Alan Carter; Hassan Baaj; Pejoohan Tavassoti. 2019. "Characterization of Asphalt Mixtures Produced with Coarse and Fine Recycled Asphalt Particles." Infrastructures 4, no. 4: 67.
Coal gangue can cause significant heavy metal pollution in mining areas, which would have a negative impact on the environment and human health. The objective of this research is to investigate the relationship between expansive soil amount and the leaching behavior of Chromium from coal gangue and the engineering properties of coal gangue used as building materials. The leaching behavior of Chromium from coal gangue was observed using atomic absorption spectrometry. A column leaching experiment was conducted to examine the impact of leaching time and heavy metal concentration. Furthermore, the unconfined compressive strength test was employed to evaluate the engineering properties of coal gangue with expansive soil. The results of the study demonstrate that pH of leachate solutions, leaching time, and expansive soil amounts in mixtures have important influence on Chromium concentration. The leachate solutions, which behave like alkaline, provide a positive environment for adsorbing Cr. Adding expansive soil can reduce leached concentrations of Chromium from coal gangue when compared to leachate of original coal gangue. It was found that 30% expansive soil was an improved solution because it delayed the cumulative concentration to reach the limitation line. Moreover, the unconfined compressive strength of coal gangue was boosted through adding expansive soil.
Yan Zhang; Hassan Baaj; Rong Zhao. Evaluation for the Leaching of Cr from Coal Gangue Using Expansive Soils. Processes 2019, 7, 478 .
AMA StyleYan Zhang, Hassan Baaj, Rong Zhao. Evaluation for the Leaching of Cr from Coal Gangue Using Expansive Soils. Processes. 2019; 7 (8):478.
Chicago/Turabian StyleYan Zhang; Hassan Baaj; Rong Zhao. 2019. "Evaluation for the Leaching of Cr from Coal Gangue Using Expansive Soils." Processes 7, no. 8: 478.
In the current era of road construction, it is common to add a small amount of reclaimed asphalt pavement (RAP) in asphalt mixes without significantly changing properties such as stiffness and low-temperature cracking resistance. Not only can these mixes be better for the environment, but they can also improve certain properties like rutting resistance. However, there is no clear understanding of how RAP gradation and bitumen properties impact the mixture properties. In this study, a single RAP source was separated into coarse and fine particles and added into a hot mix asphalt (HMA). Fourier transform infrared (FTIR) spectrometry was used to evaluate the chemical properties of the bitumen, while environmental scanning electron microscopy (ESEM) image analysis was used to visualize the differences of the virgin and RAP bitumen at a microscopic level. The observed results indicated that the recovered bitumen from coarse RAP did not have the same characteristics as the fine RAP bitumen, and the interaction of RAP bitumen with virgin bitumen significantly depended on RAP particle size. The amount of active RAP bitumen in coarse RAP particles was higher than in fine RAP particles.
Saeed S. Saliani; Alan Carter; Hassan Baaj; Peter Mikhailenko. Characterization of Recovered Bitumen from Coarse and Fine Reclaimed Asphalt Pavement Particles. Infrastructures 2019, 4, 24 .
AMA StyleSaeed S. Saliani, Alan Carter, Hassan Baaj, Peter Mikhailenko. Characterization of Recovered Bitumen from Coarse and Fine Reclaimed Asphalt Pavement Particles. Infrastructures. 2019; 4 (2):24.
Chicago/Turabian StyleSaeed S. Saliani; Alan Carter; Hassan Baaj; Peter Mikhailenko. 2019. "Characterization of Recovered Bitumen from Coarse and Fine Reclaimed Asphalt Pavement Particles." Infrastructures 4, no. 2: 24.
The concentrations of pollutants in urban pavement runoff are normally higher than those in other urban surface runoff, which causes serious problems in protecting the environment of receiving water and soils. The purpose of this study was to propose a source pollution control measure based on the spatial-temporal distribution characteristics of the runoff pollutants at urban pavement sites. Therefore, samples from pavement runoff were collected and tested for analyzing the spatial-temporal distribution characteristics. Then, infiltration tests were conducted on selected purification materials to evaluate their purification ability to the simulated pavement runoff. Results indicated that heavy metals Zn and Pb were at high concentrations near the intersection, the reason being the frequent braking of vehicles at this site. The level of suspended solids was far higher than the limitation in the standard near the site where massive human activities occurred. Besides, the cumulative amounts of all kinds of pollutants tended to be stable with the extension of rainfall duration. The logarithmic function was found to fit the experimental data well. Finally, the pavement runoff was categorized into different situations. The combinations of purification materials were recommended and integrated into a source control measure for the treatments of different pollution situations, which made the most use of each purification material and ensured the high elimination efficiency of different pollutants.
Changjiang Kou; Aihong Kang; Peng Xiao; Peter Mikhailenko; Hassan Baaj; Lu Sun; Zhengguang Wu. A Source Pollution Control Measure Based on Spatial-Temporal Distribution Characteristic of the Runoff Pollutants at Urban Pavement Sites. Applied Sciences 2018, 8, 1802 .
AMA StyleChangjiang Kou, Aihong Kang, Peng Xiao, Peter Mikhailenko, Hassan Baaj, Lu Sun, Zhengguang Wu. A Source Pollution Control Measure Based on Spatial-Temporal Distribution Characteristic of the Runoff Pollutants at Urban Pavement Sites. Applied Sciences. 2018; 8 (10):1802.
Chicago/Turabian StyleChangjiang Kou; Aihong Kang; Peng Xiao; Peter Mikhailenko; Hassan Baaj; Lu Sun; Zhengguang Wu. 2018. "A Source Pollution Control Measure Based on Spatial-Temporal Distribution Characteristic of the Runoff Pollutants at Urban Pavement Sites." Applied Sciences 8, no. 10: 1802.
The use of reclaimed asphalt pavement (RAP) is of great significance for alleviating the problem of resource waste and land space occupation in the context of asphalt pavement. However, the use rate of RAP is still low in many countries because of limited understanding and no unified recycling guidelines, especially in terms of materials classification and aging grades. In this study, reclaimed asphalt pavements from sixteen different sections in southern China were collected, including with base and polymer modified asphalt (PMA). The performance of the reclaimed asphalt binder (RAB) at low, average and high temperatures was tested, using various methods, to find suitable indexes for categorizing aging grades. The viscosity (135 °C) and penetration (25 °C) were found to distinguish the aging degree of RAB the most consistently, and served as the indices to classify the RAB into different grades. To simplify the evaluation of aging grades, a comprehensive service life was determined using the Analytic Hierarchy Process, taking service years and surface levels into account. As a result, a good correlation was found between comprehensive service life and the aging grades.
Changjiang Kou; Peng Xiao; Aihong Kang; Peter Mikhailenko; Hassan Baaj; Zhengguang Wu. Methods to Evaluate the Aging Grades of Reclaimed Asphalt Binder. Applied Sciences 2017, 7, 1209 .
AMA StyleChangjiang Kou, Peng Xiao, Aihong Kang, Peter Mikhailenko, Hassan Baaj, Zhengguang Wu. Methods to Evaluate the Aging Grades of Reclaimed Asphalt Binder. Applied Sciences. 2017; 7 (12):1209.
Chicago/Turabian StyleChangjiang Kou; Peng Xiao; Aihong Kang; Peter Mikhailenko; Hassan Baaj; Zhengguang Wu. 2017. "Methods to Evaluate the Aging Grades of Reclaimed Asphalt Binder." Applied Sciences 7, no. 12: 1209.
Highlights•The TSRST test setup was improved to measure radial strain variation during the test.•The repeatability of the TSRST is very good before the failure and reasonable for stress at failure.•The DBN and 3D-2S2P1D were used successfully to simulate the TSRST test in 3D mode.•The thermal cracking resistance remains good for mixes with up to 5% shingles and 15% RAP.•The calibration of the DBN model with 19 calibration parameters gave very good simulation of experimental data. AbstractThe thermo-mechanical behavior of asphalt mixes, with Recycled Asphalt Pavement (RAP) and manufacturing waste roofing asphalt shingles (RAS), is investigated. The cracking behavior at low temperature is studied using the Thermal Stress Restrained Specimen Test (TSRST). The experimental device has been improved with a radial strains measurement system during the performed TSRST. Tri-dimensional behavior could thus be investigated. Studied mixes are made with different RAP contents (up to 25%) and RAS contents (up to 10%). First, the influence of the content of RAP and RAS is analyzed and a ranking of the different mixes is proposed based on the classical TSRST results (stress and temperature at failure). Then, in order to simulate TSRST, a three dimensional modelling is performed with the visco-elasto-plastic DBN model. The calibration steps in the small domain (linear visco-elasticity) and in the large strain domain (non-linearity and visco-plastic flow) are presented. The comparison between experimental and simulated results obtained using the DBN model has shown the potential of the DBN model to simulate the low temperature cracking behavior of asphalt mixes.
Nouffou Tapsoba; Hassan Baaj; Cédric Sauzéat; Herve DI Benedetto; Mohsen Ech. 3D Analysis and Modelling of Thermal Stress Restrained Specimen Test (TSRST) on Asphalt Mixes with RAP and Roofing Shingles. Construction and Building Materials 2016, 120, 393 -402.
AMA StyleNouffou Tapsoba, Hassan Baaj, Cédric Sauzéat, Herve DI Benedetto, Mohsen Ech. 3D Analysis and Modelling of Thermal Stress Restrained Specimen Test (TSRST) on Asphalt Mixes with RAP and Roofing Shingles. Construction and Building Materials. 2016; 120 ():393-402.
Chicago/Turabian StyleNouffou Tapsoba; Hassan Baaj; Cédric Sauzéat; Herve DI Benedetto; Mohsen Ech. 2016. "3D Analysis and Modelling of Thermal Stress Restrained Specimen Test (TSRST) on Asphalt Mixes with RAP and Roofing Shingles." Construction and Building Materials 120, no. : 393-402.