scholarly journals Evaluation of the Additives’ Behaviour to Determine the Best Modifier for Improving Asphalt Performance at High Temperature

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Ismail Bakheit Eldouma ◽  
Huang Xiaoming

The current study aims to examine the physical and rheological properties at the high-temperature range of 52, 58, 64, 70, 76, and 82°C, utilizing adjusted asphalt binders. Three kinds of asphalt modifiers were selected such as styrene-butadiene-styrene, ethylene vinyl acetate, and end of life tires. The selected additives were implemented with different contents ranging from 4% to 7% by the weight of neat asphalt. Various test methods have been established, such as ductility, viscosity, microscopic inspection, and dynamic shear rheometer experiments. Results proved that the percentage decrease in ductility was 93%, 91%, and 88% with regard to the adding of the end of life tires (ELTs), ethylene vinyl acetate (EVA), and styrene-butadiene-styrene (SBS) additives, respectively. Outcomes also confirmed that viscosity was boosted from 0.411 Pa.s to 1.249, 1.0986, and 0.9785 Pa.s after adding 7% of ELTs, 7% of EVA, and 7% of SBS, respectively. The rutting parameter and complex shear modulus increased after modification, indicating the excellent performance of asphalt. The conclusions confirmed that the ELTs have fewer agglomerates and have good compatibility before ageing and excellent compatibility after the ageing process. Thus, the ELTs are deemed as efficient dispersion additive for avoiding separation during the storage and handling of the asphalt binder. Lastly, ELTs were accepted as the best enhancer for their positive influence on physical and rheological characteristics, which means higher quality amended bitumen would give higher resistance to permanent deformation.

2017 ◽  
Vol 50 (3) ◽  
pp. 241-255 ◽  
Author(s):  
Seyfullah Keyf

In this article, 50/70 penetration grade TUPRAS bitumen was modified. Reactive elastomeric terpolymer (Elvaloy RET; DuPont Company), ethylene vinyl acetate (EVA) and styrene–butadiene–styrene (SBS) polymers were used in bitumen modification. Set hours of the tests were applied to samples taken from the obtained modified bitumen mixture. Varying amount of reactive ethylene terpolymer with weight ratios of 0.5%, 1.0%, 1.5%, 2.0% and 2.5% were introduced to the mixture of raw bitumen with 1.0% SBS and 1.0% EVA. Penetration, penetration index, softening point, ductility and elastic recovery tests were performed with these modified bitumen and raw bitumen. The samples of raw bitumen and modified bitumens of 2.0% Elvaloy RET, 1.0% SBS and 1.0% EVA were investigated by means of IR spectroscopy. The raw bitumen was modified with SBS, EVA and RET, and it was determined that penetration and ductility values were decreased while penetration index, softening point and elastic recovery were increased. The purpose of this study is to research the improving properties of 50/70 penetration grade–modified bitumen used in highways of Turkey. The most important characteristics (such as softening point, penetration and % elastic recovery) of new polymer-modified bitumen (NPMB) containing 2.5% EVA, 1% RET and 1% SBS were compared with eight different types of polymer-modified bitumens in Turkey (TPMB). NPMB provided all required parameters (softening point, penetration and % elastic recovery) for five different types of TPMBs (TPMB 70-16, TPMB 70-22, TPMB 76-16, TPMB 76-22 and TPMB 82-16).


Polymers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 2249
Author(s):  
Bei Chen ◽  
Fuqiang Dong ◽  
Xin Yu ◽  
Changjiang Zheng

In order to solve the problems caused by asphalt diseases and prolong the life cycle of asphalt pavement, many studies on the properties of modified asphalt have been conducted, especially polyurethane (PU) modified asphalt. This study is to replace part of the styrene-butadiene-styrene (SBS) modifier with waste polyurethane (WP), for preparing WP/SBS composite modified asphalt, as well as exploring its properties and microstructure. On this basis, this paper studied the basic performance of WP/SBS composite modified asphalt with a conventional performance test, to analyze the high- and low-temperature rheological properties, permanent deformation resistance and storage stability of WP/SBS composite modified asphalt by dynamic shear rheometer (DSR) and bending beam rheometer (BBR) tests. The microstructure of WP/SBS composite modified asphalt was also observed by fluorescence microscope (FM) and Fourier transform infrared spectroscopy (FTIR), as well as the reaction between WP and asphalt. According to the results of this study, WP can replace SBS as a modifier to prepare WP/SBS composite modified asphalt with good low-temperature resistance, whose high-temperature performance will be lower than that of SBS modified asphalt. After comprehensive consideration, 4% SBS content and 15% WPU content (4 S/15 W) are determined as the suitable types of WPU/SBS composite modified asphalt.


2021 ◽  
Vol 1036 ◽  
pp. 459-470
Author(s):  
Hong Gang Zhang ◽  
Qiang Huai Zhang ◽  
Xue Ting Wang ◽  
Hua Tan ◽  
Li Ning Gao ◽  
...  

A styrene-butadiene-styrene triblock copolymer (SBS) was grafted with an unsaturated polar monomer (monomer A) composed of maleic anhydride (MAH) and methoxy polyethylene (MPEG) via a ring-opening reaction after epoxidizing styrene-butadiene-styrene triblock copolymer (ESBS). The microscopic changes of SBS before and after grafting has been characterized with Fourier transform infrared spectrum (FT-IR), X-ray photoelectron spectroscopy (XPS) and gel permeation chromatography (GPC). The results revealed that the monomer A was successfully grafted on SBS backbone, and the maximum graft ratio (GR) was 20.32%. To verify the compatibility between SBS and asphalt, solubility parameters and surface free energy (SFE) of SBS, grafted SBS and asphalt were measured. It was found that the solubility parameter and SFE of grafted SBS were closer to asphalt compared with SBS. It also has been confirmed from storage stability that the temperature susceptibility of grafted SBS modified asphalt was reduced in compare with SBS modified asphalt binder. As consequence, the use of grafted copolymer can be considered a suitable alternative for modification of asphalt binder in pavement.


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