scholarly journals Evaluating Fly Ash-Based Geopolymers as a Modifier for Asphalt Binders

2020 ◽  
Vol 2020 ◽  
pp. 1-11 ◽  
Author(s):  
Abdulrahman Hamid ◽  
Hamed Alfaidi ◽  
Hassan Baaj ◽  
Mohab El-Hakim

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.

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Hyun Hwan Kim ◽  
Mithil Mazumder ◽  
Moon-Sup Lee ◽  
Soon-Jae Lee

In this study, performance properties of polymer-modified asphalt (PMA) binders are evaluated depending on ground tire rubber (GTR) and styrene-isoprene-styrene (SIS). Styrene-butadiene-styrene- (SBS-) modified asphalt binder of PG 76-22 is used as a base binder to manufacture the rubberized PMA binder. The rubberized PMA binders are blended using SIS modifier. The binders were artificially short-term and long-term aged using rolling thin-film oven (RTFO) and pressure aging vessel (PAV) procedures. Superpave binder tests were conducted on the binders through rotational viscometer (RV), dynamic shear rheometer (DSR), and bending beam rheometer (BBR). Furthermore, multiple stress creep recovery (MSCR) test and atomic force microscopy (AFM) microstructural analysis were performed. The results of this study indicated that (1) the viscosity properties seem to be highly dependent on GTR and SIS contents, (2) the addition of SIS is observed to have a significant effect on improving the rutting performances of rubberized PMA binders, (3) the cracking properties are considered to be improved significantly through SIS modification, and (4) in general, the rubberized PMA binders with SIS showed the best performance for rutting and cracking among all the binders used in this study.


2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Mithil Mazumder ◽  
Anwar Siddique ◽  
Raju Ahmed ◽  
Soon-Jae Lee ◽  
Moon-Sup Lee

The demand of strong polymer modified asphalt (PMA) binder is growing due to the increase of traffic and necessity to reduce the early deterioration of pavement due to cracking. In this study, physical and rheological properties of asphalt binder modified with a potential new polymer named styrene-isoprene-styrene (SIS) were investigated through the rotational viscometer (RV), the dynamic shear rheometer (DSR), and the bending beam rheometer (BBR). In order to have a depth understanding on the SIS binder at micro level, micro-morphological observations were conducted using optical microscopy, atomic force microscopy (AFM), environmental scanning electron microscopy (ESEM), and ellipsometry. The result of this study showed that (1) the addition of SIS modifiers increased the viscosity and had a positive effect on rutting resistance of the binder; (2) the addition of 5%, 10%, 15%, and 20% SIS content increased the rutting resistance by 600%, 3000%, 5600%, and 6400%, respectively; (3) the higher the SIS content, the better the cracking resistance of the binder and it is observed to have improved the stiffness by 26% and 51% with the addition of 5% and 10% content of SIS, respectively; (4) AFM images showed the significant correlation between the stiffness and microstructural properties of the binder; (5) the dominance of new oval phase over network structure was evident in ESEM images and observed to have significant correlation to the high stiffness of the binder; and (6) with the percentage increase of SIS modifier, the binder is found to have higher absorption at UV wavelength.


2021 ◽  
Vol 11 (19) ◽  
pp. 9242
Author(s):  
Xiaobing Chen ◽  
Yunfeng Ning ◽  
Yongming Gu ◽  
Ronglong Zhao ◽  
Jinhu Tong ◽  
...  

To investigate the influence of multiple cycles of aging and rejuvenation on the rheological, chemical, and morphological properties of styrene–butadiene–styrene (SBS)-modified asphalt-binders, the asphalt-binders were aged using two laboratory simulation methods, namely a rolling thin film oven (RTFO) test for short-term aging and pressure aging vessel (PAV) for long-term aging. The asphalt-binders were then rejuvenated with three types of rejuvenators (Type I, II, and III) with different dosages (i.e., 6%, 10%, and 14% for the first, second, and third rejuvenation, respectively). A dynamic shear rheometer (DSR) was then used to analyze the effect of rejuvenators on the rheological properties of all the asphalt-binders. The changes in the functional groups and microscopic morphology in the process of multiple aging and rejuvenation cycles were studied using Fourier transform infrared (FTIR) and atomic force microscopy (AFM). The results indicated that the three rejuvenators could soften the stiffness and restore the microstructures of the aged asphalt-binders in the process of repeated aging and rejuvenation from DSR and AFM testing. Considering the rutting and fatigue properties, the Type I rejuvenator exhibited the potential to achieve the desired rejuvenation effects under multiple rejuvenation cycles. During the multiple aging and rejuvenation cycles, the aging resistance of SBSMA decreased gradually from the FTIR results. This inherently limited the number of repeated rejuvenation cycles. This research is conducive to promoting the application of repeated penetrating rejuvenation.


2019 ◽  
Vol 271 ◽  
pp. 03006
Author(s):  
Mohammad N. Hassan ◽  
M M Tariq Morshed ◽  
Zahid Hossain

Asphalt binders are often modified with additives such as acid, polymer, or a combination of multiple additives to achieve improved performance to sustain heavy loads and adverse weather conditions. According to some previous researches, nanoclay can be a good alternative of currently practiced Styrene-Butadiene-Styrene (SBS) modification, and the former is expected to reduce the overall cost of the asphalt binder. Three types of nanoclay (Cloisite 10A, 11B, and 15A) were blended with asphalt binders prepared from two different sources (Arabian Crude and Canadian Crude). A blending protocol has been developed to blend nanoclay with the base binders. Mechanical properties including viscosity, rutting parameter have undergone significant changes after the nanoclay modification. It was also observed that nanoclay modified binders offer different moisture susceptibility while bonding with different aggregates; the nanoclay modified asphalt binder exhibits better bonding with gravel than sandstone. Mechanistic properties such as viscosity and rutting parameter are found to be highly correlated with the chemical compositions. Binders from the Canadian crude showed more colloidal stability than binders from the Arabian crude after nanoclay modification.


Fibers ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 25
Author(s):  
Ang Li ◽  
Abdu A. Danladi ◽  
Rahul Vallabh ◽  
Mohammed K. Yakubu ◽  
Umar Ishiaku ◽  
...  

Cellulose microfibrils (CMFs) and micronized rubber powder (MRP) can be derived from low or negative-cost agricultural/industrial waste streams and offer environment-friendly and cost-effective pathways to develop engineering products. This study investigated the efficacy of adding these micromodifiers on the performance characteristics of asphalt binders. In this work, samples were produced using a mixture of slow-setting anionic asphalt emulsion with various combinations of MRP (at 0, 2 and 10 wt %) and four types of CMFs (hydrophobic and hydrophilic with crystalline ratios of 86% and 95%) at 0, 2 and 5 wt %. The performance of modified asphalt samples was assessed by penetration depth (PD), softening point (SP), and penetration index (PI). Linear regression analysis showed that adding CMFs and/or MRP reduced PD and increased SP values. The type of CMFs significantly affected the performance, which becomes more distinct with the increased weight content of CMFs. While hydrophilic CMFs caused increases in SP and PI values, no clear trend was seen to determine the effect of CMF crystallinity. It was also discovered that the combined addition of CMF and MRP achieved similar PI values at lower total weight content compared to using MRP alone.


2017 ◽  
Vol 2630 (1) ◽  
pp. 110-117 ◽  
Author(s):  
Matheus S. Gaspar ◽  
Kamilla L. Vasconcelos ◽  
Amanda H. M. da Silva ◽  
Liedi L. B. Bernucci

Reflective cracking is a common issue with respect to rehabilitated asphalt pavements, especially when the rehabilitation is done by applying a hot-mix asphalt overlay on the existing damaged pavement. Several approaches can be adopted to delay reflective cracking. They include an increase of the overlay thickness and the use of a stress relief asphalt mixture (SRAM), which is a fine-graded, flexible, and thin asphalt interlayer. Because the efficiency of a SRAM is highly related to the properties of the asphalt binder used in the mixture, it is of interest to use a highly modified asphalt (HiMA) binder. This paper describes a field test comprising three sections at BR-116 (a heavily trafficked highway in Brazil). One of the rehabilitation strategies used for a cracked asphalt pavement was a 2.5-cm SRAM (produced with a HiMA binder) and 5-cm styrene–butadiene–styrene (SBS) hot-mix asphalt (HMA). The other two strategies were to apply SBS HMA overlays of different thicknesses (7.5 cm and 10.5 cm). The aim was to evaluate and compare the capability of these solutions to control reflective cracking. Rheological properties and multiple stress creep and recovery tests were performed on the asphalt binders, and the semicircular bending test was performed on the asphalt mixtures. The surface conditions were monitored, and the results for each section were compared. After a 29-month period, the section that received the interlayer had the lowest cracked area and showed better resistance than the overlays did to reflective cracking and better maintenance of the original thickness of the pavement.


2012 ◽  
Vol 178-181 ◽  
pp. 1509-1512 ◽  
Author(s):  
Hussain Arshad ◽  
Yan Jun Qiu

Premature rutting due to high temperatures and heavy loads has been a major distress on flexible pavements in Pakistan. One of the main causes of this early rutting is the available asphalt binders, which are still graded by using penetration grading system. The penetration grading system is based on empirical tests and does not link with performance. To improve the quality of the flexible pavement and to avoid the premature rutting the performance based testings were conducting in laboratory. This study evaluated performance graded (PG) binders for use in pavement construction in the country. Five different penetration graded asphalt binder, typically available in the country were graded according to PG system. The performance grades (PG) for all binders were determined based on DSR and BBR results. The two same penetration grades ARL60/70 and NRL 60/70 have different PG grades. The two different penetration grades ARL60/70 and NRL 80/100 have same PG grade. The results show that the local binders are very soft due to which they performed poorly at high temperatures and prone to severe rutting.


2011 ◽  
Vol 71-78 ◽  
pp. 1062-1067 ◽  
Author(s):  
Zhen Gang Feng ◽  
Jian Ying Yu ◽  
Heng Long Zhang ◽  
Dong Liang Kuang

The modified asphalt binders with various anti-ageing additives, including ultraviolet (UV) absorber, antioxidant and combination of them, were prepared, and the effects of UV absorber contents, antioxidant contents and combination of UV absorber and antioxidant on physical properties and ageing characteristics of the asphalt binder were investigated. Results show that the ductility of asphalt binder increases whereas the softening point and viscosity decrease with addition of anti-ageing additives. UV absorbers and antioxidants exhibit different influences on the ageing properties of asphalt binder. The thermal- and photo-oxidative ageing performance of asphalt binder can be simultaneously improved by the compound modification with UV absorber and antioxidant. The combination of UV326 and antioxidant 1010 shows synergistic effect in preventing the asphalt binder from thermal- and photo-oxidative ageing, which contributes to excellent ageing resistance of modified asphalt binder.


Author(s):  
Saqib Gulzar ◽  
B. Shane Underwood

Agencies have been increasing their use of polymer modified asphalt binders in recent years to address performance issues and lengthen the useful life of their pavements. When deployed these materials likely experience strain levels exceeding their linear viscoelastic (LVE) limits. The same situation exists in non-polymer modified asphalt binders as well, but the effect may be more pronounced in polymer modified systems because of their bi-phasic nature. In this study, terminally blended crumb rubber (CR-TB) modified asphalt is studied to understand and quantify the nonlinear viscoelastic response under large strains. The CR-TB binders are extensively used in pavements subjected to high vehicular loads and extreme climatic conditions; thereby, their response under large strains becomes more critical. The current standard characterization techniques are based on LVE response using small amplitude oscillatory shear rheology only and do not consider the behavior of binders under large strains. In this study, large amplitude oscillatory shear (LAOS) rheology is used as a framework to more thoroughly investigate the complete response of the CR-TB modified asphalt binder under large strains at 30°C, 40°C, 50°C, and 60°C and at the frequencies of 0.5, 1, and 5 Hz. The LAOS response is analyzed using Fourier-transform rheology and the orthogonal stress decomposition method involving Chebyshev polynomial representation. It is found that nonlinearity manifests greatly in this study material as strain levels increase and frequencies decrease. The relative nonlinearity increases with increasing strain amplitude and is more significant towards lower end of the tested temperature range. The CR-TB binder shows strain-stiffening/softening and shear-thinning/thickening behavior depending upon a specific temperature, strain level, and frequency.


2016 ◽  
Vol 78 (7-2) ◽  
Author(s):  
Ahmad Nazrul Hakimi Ibrahim ◽  
Nur Izzi Md. Yusoff ◽  
Norliza Mohd Akhir ◽  
Muhamad Nazri Borhan

This study was conducted to investigate the physical properties and storage stability of the 80/100 penetration grade asphalt modified with geopolymer. In this research, fly ash and alkali activators, namely sodium silicate (Na2SiO3) and sodium hydroxide (NaOH), were used as geopolymer components. The penetration, Ring and Ball softening point, ductility, and viscosity tests were conducted to determine the physical properties of geopolymer modified asphalt (GMA). Five samples of asphalt binders with varying percentages of geopolymer, namely 0, 3, 5, 7 and 9%, by weight of asphalt binder were studied. Results show that geopolymer has good compatibility with asphalt binder. The addition of geopolymer into asphalt binder resulted in improved permanent deformation resistance of the modified binder compared to that of the conventional asphalt. In conclusion, geopolymer could be considered as a potential alternative in the modification of the properties of asphalt binder.


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