00669039

Component

http://onlinepubs.trb.org...trr/1994/1436/1436-007.pdf

https://scholar.google.co...Hesp&publication_year=1994

One of the key factors that determines the susceptibility of a pavement to thermal cracking is the ability of the binder to withstand or relieve thermal stresses before they reach a critical point where cracks form. The mechanisms by which the addition of polyethylene improves the low-temperature properties of asphalt binders are discussed. Also examined is the degree to which the quality of the additive dispersion influences these mechanisms. Notched bending beam tests conducted at -20 deg C yielded fracture toughness values for three different polyethylene-asphalt systems. In all systems studied, the fracture toughness was found to increase linearly with the additive content. The chlorinated polyethylene-modified binders produced the toughest samples, followed by the stabilized polyethylene and the unstabilized polyethylene binders, respectively. High-magnification photographs, made with an environmental scanning electron microscope, yielded additional information concerning the nature of the failure mechanisms in these systems. The combined results show that greater toughening occurs with more finely dispersed polymers and with greater compatibility at the interface between the polymer and the asphalt matrix. These observations are consistent with the mechanisms of crack pinning and shear yielding, both of which are regularly found in multiphase thermoplastic materials.

This paper appears in Transportation Research Record No. 1436, Asphalt Concrete Mix Materials. Distribution, posting, or copying of this PDF is strictly prohibited without written permission of the Transportation Research Board of the National Academy of Sciences. Unless otherwise indicated, all materials in this PDF are copyrighted by the National Academy of Sciences. Copyright © National Academy of Sciences. All rights reserved

01401249

English

p. 54-59

1994-10

Transportation Research Record

030905513X

Figures (6) ; References (29) ; Tables (2)

Asphalt; Ethylene resins; Failure; Fracture properties; Low temperature; Testing

Polyethylene

Highways; Materials; I31: Bituminous Binders and Materials

TRIS, TRB

Nov 23 1994 12:00AM

• DESIGNING ASPHALT PAVEMENTS FOR EXTREME CLIMATES
• EFFECT OF ANTISTRIP ADDITIVES ON THE PROPERTIES OF POLYMER-MODIFIED ASPHALT BINDERS AND MIXTURES
• EFFECT OF COMPOSITION ON ASPHALT RECYCLING AGENT PERFORMANCE
• EMPIRICAL EVALUATION OF OLIVE HUSK IN ASPHALT CEMENT BINDER AND BITUMINOUS CONCRETE
• EVALUATION AND CHARACTERIZATION OF A RUBBER-MODIFIED HOT MIX ASPHALT PAVEMENT
• EVALUATION AND FIELD VALIDATION OF PROPOSED STRATEGIC HIGHWAY RESEARCH PROGRAM BINDER SPECIFICATION FOR THERMAL CRACKING
• EVALUATION OF NATURAL SANDS USED IN ASPHALT MIXTURES
• IMPROVED LOW-TEMPERATURE FRACTURE PERFORMANCE FOR RUBBER-MODIFIED ASPHALT BINDERS
• INVESTIGATION OF LABORATORY AGING PROCESSES OF ASPHALT BINDERS USED IN FLORIDA
• INVESTIGATION OF RUTTING OF ASPHALT SURFACE LAYERS: INFLUENCE OF BINDER AND AXLE LOADING CONFIGURATION
• RHEOLOGICAL AND RHEO-OPTICAL CHARACTERIZATION OF ASPHALT CEMENT AND EVALUATION OF RELAXATION PROPERTIES
• SOFTENING OF ASPHALTS IN DILUTE SOLUTIONS AT PRIMARY DISTILLATION CONDITIONS
• STUDY OF THE FATIGUE OF ASPHALT MIXES USING THE CIRCULAR TEST TRACK OF THE LABORATOIRE CENTRAL DES PONTS ET CHAUSSEES IN NANTES, FRANCE
• USE OF RUBBER IN ASPHALT PAVEMENTS: KANSAS EXPERIENCE