scholarly journals Investigation of the Physical and Molecular Properties of Asphalt Binders Processed with Used Motor Oils

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Mohyeldin Ragab ◽  
Magdy Abdelrahman
Keyword(s):  
Low Temperature ◽  
Molecular Size ◽  
Gel Permeation Chromatography ◽  
Crumb Rubber ◽  
Asphalt Binders ◽  
Internal Network ◽  
Molecular Sizes ◽  
Short And Long Term ◽  
Molecular Size Distribution ◽  
Motor Oils

In this work we investigated the performance aspects of addition of used motor oils (UMO) to neat and crumb rubber modified asphalts (CRMA) and related that to the change of molecular size distribution of modified asphalt’s fractions; asphaltenes, saturates, naphthene aromatics, and polar aromatics. Based on the results of temperature sweep viscoelastic tests, addition of crumb rubber modifier (CRM) alone or with UMO results in the formation of internal network within the modified asphalt. Based on the results of short and long term aged asphalts, the utilization of combination of UMO and CRM enhanced the aging behavior of asphalt. Bending beam rheometer was utilized to investigate the low temperature behavior of UMO modified asphalts. Based on those tests, the utilization of the UMO and CRM enhanced the low temperature properties of asphalts. Based on the results of the asphalt separation tests and the Gel Permeation Chromatography (GPC) analysis, it was found that saturates and naphthene aromatics are the two asphalt fractions that have similar molecular size fractions as those of UMO. However, UMO only shifts the molecular sizes of saturates after interaction with asphalt. Results also show that polar aromatics pose higher molecular size structures than UMO.

scholarly journals Evaluation of Micro-Mechanism and High- and Low-Temperature Rheological Properties of Disintegrated High Volume Crumb Rubber Asphalt (DHVRA)

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1145
Author(s):  
Wei Li ◽  
Sen Han ◽  
Xiaokang Fu ◽  
Ke Huang
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Rheological Properties ◽  
Particle Diameter ◽  
Gel Permeation Chromatography ◽  
High Volume ◽  
Crumb Rubber ◽  
Test Method ◽  
Polar Component ◽  
Temperature Performance

The aims of this paper are to prepare disintegrated high volume crumb rubber asphalt (DHVRA) with low viscosity, good workability and low-temperature performance by adding disintegrating agent (DA) in the preparation process, and to further analyze the disintegrating mechanism and evaluated high-temperature and low-temperature rheological properties. To obtain DHVRA with excellent comprehensive performance, the optimum DA dosage was determined. Based on long-term disintegrating tests and the Fluorescence Microscopy (FM) method, the correlations between key indexes and crumb rubber (CR) particle diameter was analyzed, and the evaluation indicator and disintegrating stage division standard were put forward. Furthermore, Fourier transform infrared spectroscopy (FT-IR) and Gel Permeation Chromatography (GPC) was used to reveal the reaction mechanism, and the contact angle test method was adopted to evaluate the surface free energy (SFE). In addition, the high-temperature and low-temperature rheological properties were measured, and the optimum CR content was proposed. Results indicated that the optimum DA dosage was 7.5‰, and the addition of DA promoted the melt decomposition of CR, reduced the viscosity and improved the storage stability. The 135 °C rotational viscosity (RV) of DHVRA from mixing for 3 h could be reduced to 1.475 Pa·s, and the softening point difference was even less than 2 °C. The linear correlation between 135 °C RV and the diameter of CR particle in rubber asphalt system was as high as 0.968, and the viscosity decay rate (VDR) was used as the standard to divide the disintegrating process into a fast disintegrating stage, stable disintegrating stage and slight disintegrating stage. Compared to common rubber asphalt (CRA), DHVRA has an absorption peak at 960 cm−1 caused by trans olefin = C-H, and higher molecular weight and polar component of surface energy. Compared with CRA, although the high-temperature performance of DHVRA decreases slightly, the low-temperature relaxation ability can be greatly improved.

Evaluation of Adhesion Properties of Modified Asphalt Binders with Use of Binder Bond Strength Test

2017 ◽  
Vol 2632 (1) ◽  
pp. 88-98 ◽  
Author(s):  
Weidong Huang ◽  
Lu Zhou
Keyword(s):  
Bond Strength ◽  
Asphalt Binder ◽  
Gel Permeation Chromatography ◽  
Crumb Rubber ◽  
Asphalt Binders ◽  
Adhesion Properties ◽  
Rubber Powder ◽  
Positive Effects ◽  
Tracking Device ◽  
Styrene Butadiene

Moisture damage is a prominent problem of asphalt pavements. The bond strength between asphalt and aggregates is a crucial factor that influences the capability of asphalt to resist moisture-induced damage. In this study, a binder bond strength (BBS) test was conducted to evaluate the effects of various modifiers and additives of different amounts on bond strength between asphalt and aggregates. Furthermore, the influence of styrene–butadiene–styrene (SBS) on adhesion behavior of asphalt binder was investigated through a gel permeation chromatography (GPC) test. Finally, the results of the BBS test were compared with the findings obtained from a Hamburg wheel-tracking device (HWTD) test, which reflected the moisture sensitivity of mixtures under wet conditions. Results indicated that gilsonite, high-density polyethylene, and polyphosphoric acid improved the bond strength of the base asphalt; SBS had no positive effects on asphalt adhesion properties; and SBS at a low amount reduced the bond strength. Ethylene bis-stearamide wax, crumb rubber, terminal blend (TB) rubber powder, and compound modifier TB rubber powder plus SBS decreased the bond strength. The GPC test results showed that SBS possibly did not actively contribute to the formation of bond strength between asphalt and aggregates. Test data for BBS and HWTD tests under wet conditions confirmed that there was no discernible correlation between these two tests when adhesion properties of modified asphalts were evaluated. However, the results of the BBS test were in accordance with those of the HWTD test when the adhesion of asphalt with different amounts of the same modifier and the mixture resistance to water damage were evaluated.

Recycling of Plastic and Rubber Tire Waste in Asphalt Pavements

1994 ◽  
Vol 344 ◽  
Author(s):  
Geoffrey R. Morrison ◽  
Nolan K. Lee ◽  
Simon A.M. Hesp
Keyword(s):  
Fracture Toughness ◽  
High Temperature ◽  
Low Temperature ◽  
Local Governments ◽  
Complex Modulus ◽  
Loss Modulus ◽  
Crumb Rubber ◽  
Asphalt Binders ◽  
Rubber Tire ◽  
Temperature Fracture

AbstractThis paper discusses some important issues related to the use of recycled thermoplastics and rubber tire waste in asphalt binders for hot-mix pavements. Both high temperature rheological and low temperature fracture studies are presented on recycled polyethylene, devulcanized and crumb rubber-modified asphalt binders. The results are compared to unmodified and commercially available modified binders. This research is especially timely in light of the U.S. Intermodal Surface Transportation Efficiency Act of 1991, Section 1038 which, starting in 1995, will force state and local governments to use significant amounts of recycled rubber tire or plastic waste in federally funded highway projects.High temperature rheological measurements of the loss modulus, loss tangent and complex modulus show a significant improvement when only small quantities of crumb rubber, devulcanized crumb rubber or waste polyethylene are added to the asphalt binders.The low temperature fracture performance of the modified asphalts is greatly influenced by the interfacial strength between the dispersed and continuous phase. The fracture toughness increases dramatically, only when low molecular weight polymers are grafted in-situ onto the rubber and polymer dispersed phases in order to strengthen the interface. This points to a crack-pinning mechanism as being responsible for the dramatic increase in fracture toughness that is observed in this work. Single phase, devulcanized crumb rubber-asphalt systems perform quite poorly at low temperatures.

Development of Rubber and Asphalt Binders by Depolymerization and Devulcanization of Scrap Tires in Asphalt

1996 ◽  
Vol 1530 (1) ◽  
pp. 51-58 ◽  
Author(s):  
Ludo Zanzotto ◽  
Gerhard J. Kennepohl
Keyword(s):  
Gel Permeation Chromatography ◽  
Crumb Rubber ◽  
Asphalt Binders ◽  
Temperature Sensitive ◽  
High Shear ◽  
Reaction Products ◽  
Scrap Tires ◽  
Creep And Recovery ◽  
Conventional Tests ◽  
Gel Permeation

Scrap tires in three forms—crumb rubber 60 minus mesh, crumb rubber 20 minus mesh, and buffed rubber—were subjected to depolymerization and devulcanization by applying heat, high shear, and a combination of both. Different reaction temperatures and times of reaction were applied. The reaction products were submitted to the testing of rheological properties by measurement of creep and recovery, viscosity, and some conventional tests. The amount of unreacted rubber and tendency to separation during the hot storage were also tested. Selected materials were evaluated according to SHRP specification and by the gel permeation chromatography. The results from the SHRP testing indicate that these materials are less temperature sensitive than conventional asphalts prepared from the same crude oil as the base asphalt. These materials were prepared in larger quantities and are being tested for their performance in paving mixes.

Theory of molecular size distribution In multichain polymers

1970 ◽  
Vol 48 (1) ◽  
pp. 33-45 ◽  
Author(s):  
S. G. Whiteway ◽  
I. B. Smith ◽  
C. R. Masson
Keyword(s):  
Functional Groups ◽  
Entire Range ◽  
Molecular Size ◽  
Degree Of Polymerization ◽  
Probable Distribution ◽  
Molecular Sizes ◽  
Intramolecular Condensation ◽  
Meaningful Existence ◽  
Molecular Size Distribution ◽  
Most Probable Distribution

Expressions are derived for the most probable distribution of molecular sizes in multi-chain polymers formed by the self-condensation of the monomer A—R—Xf − 1, where A and X are functional groups and X may be either A or B. It is assumed that all functional groups of the same kind are chemically equivalent and that intramolecular condensation may be neglected. For the case A—R—Bf − 1 the results are identical with those of Flory, although it is shown that this is fortuitous and due to a cancellation of two errors in Flory's method. For the case R—Af the results differ significantly from expressions derived by Flory and sources of error in previous work are discussed. In theory, the mole and weight fractions of individual x-mers vary continuously with the extent of reaction α over the entire range up to αmax = 2/f. The ratio of the weight average to the number average degree of polymerization is finite for all values of α below αmax. The critical point for the formation of infinitely large (wall-to-wall) molecules occurs, not at α = 1/(f − 1) as predicted by Flory, but at α = 2/f. The prediction of actual gel points is discussed in terms of the largest molecule which can have a physically meaningful existence at any fixed value of α.

scholarly journals Aging Properties and Mechanism of Microwave-Activated Crumb Rubber Modified Asphalt Binder

2020 ◽  
Vol 7 ◽  
Author(s):  
Tao Zhou ◽  
Jianing Zhou ◽  
Qidong Li ◽  
Bo Li
Keyword(s):  
Functional Group ◽  
Asphalt Binder ◽  
Molecular Size ◽  
Gel Permeation Chromatography ◽  
Aging Effect ◽  
Microwave Treatment ◽  
Crumb Rubber ◽  
Microwave Activation ◽  
Modified Asphalt ◽  
Before And After

Although crumb rubber modified asphalt (CRMA) has a better performance than matrix asphalt (MA) in road engineering, the application bottlenecks of this material lies in its high viscosity, poor workability and bad storage stability. Microwave technology is one of the solutions to the above problems. The objective of this study was to investigate the physical and chemical changes before and after aging of CRMA which was prepared by microwave activated crumb rubber, and the aging mechanism of microwave-activated crumb rubber modified asphalt (MACRMA). Through penetration, softening point, ductility, viscosity and DSR test, the high and low temperature performance and temperature sensitivity of MA, CRMA and MACRMA before and after aging were studied. These tests results revealed that microwave treatment can improve the anti-rutting ability and the anti-aging performance of rubber asphalt. According to gel permeation chromatography (GPC) test, the distribution changes of the internal molecular content of the three asphalts were determined during the aging process. Its test results showed that aging effect accelerated the conversion of small molecules to large molecules in asphalt, and the value of large molecular size (LMS) increases more after long-term aging. The microwave activation made the swelling reaction more intense, thereby delayed the conversion of LMS in the rubber asphalt. In addition, LMS has a high correlation with test indicators. The fourier transform infrared spectroscopy (FTIR) test was used to measure the functional group changes of each asphalt. The FTIR spectra indicated that microwave activation is mainly a process of physical change. The carbonyl and sulfoxide functional group indices of MACRMA were lower than those of MA and CRMA, which also confirmed that MACRMA has a better anti-aging ability.

Determination of the Size Distribution of Dissolved Organics in Effluents

1973 ◽  
Vol 8 (1) ◽  
pp. 1-15 ◽  
Author(s):  
L.A. Addie ◽  
K.L. Murphy ◽  
J.L. Robertson
Keyword(s):  
Size Distribution ◽  
Biological Treatment ◽  
Oxygen Demand ◽  
Molecular Size ◽  
Monitoring Systems ◽  
Clean Surface ◽  
Sephadex Column ◽  
Dissolved Organics ◽  
Molecular Size Distribution

Abstract The importance of removing the small amounts of residual organics is increasing as the sources of clean surface water decrease. Knowledge of the nature of these soluble residual organics will be needed in order to assess the type of treatment required for their removal. Residual organics in three different biological treatment plants were analyzed and compared. An attempt was made to characterize these organics by a molecular size distribution on a Sephadex column monitored by differential ultraviolet and refractive index detectors. The organic carbon and chemical oxygen demand of the fractions collected from the column was also determined. An investigation of some of the problems inherent in the monitoring systems was conducted.

Sign in / Sign up

Export Citation Format

Share Document