00464511

Component

http://onlinepubs.trb.org...trr/1987/1110/1110-001.pdf

http://publications.iowa.gov/19647/

https://scholar.google.co...arks&publication_year=1987

Some of Iowa's 13,200 miles of portland cement concrete (pcc) pavement have remained structurally sound for more than 50 years, while others have suffered premature deterioration. Research has shown that the type of coarse aggregate used in the pcc is the major cause of this premature deterioration. Some coarse aggregates for concrete exhibit a nonuniform performance history. They contribute to premature deterioration on heavily salted primary roadways while providing long maintenance-free life on unsalted secondary pavements. This inconsistency supports the premise that there are at least two mechanisms that contribute to the deterioration. Previous research has shown that one of these mechanisms is a bad pore system. The other is apparently a chemical reaction. The objective of this research is to develop simple rapid test methods to predict the durability of carbonate aggregate in pcc pavement. X-ray diffraction analyses of aggregate samples have been conducted on various beds from numerous quarries producing diffraction plots for more than 200 samples of dolomitic or dolomite aggregates. The crystalline structures of these dolomitic aggregates show maximum-intensity dolomite/ankerite peaks ranging from a d-spacing of 2.884 angstroms for good aggregates to a d-spacing of 2.914 angstroms for nondurable aggregates. If coarse aggregates with known bad pore systems are removed from this summary, the d-spacing values of the remaining aggregates correlate well with expected service life. This may indicate that the iron substitution for magnesium in the dolomite crystal is associated with the instability of the ferroan dolomite aggregates in pcc pavement.

Publication of this paper sponsored by Committee on Performance of Concrete. 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

01492602

pp 1-10

1987

Transportation Research Record

66th Annual Meeting of the Transportation Board

030904460X

Print

Figures (8) ; Photos (4) ; References (7) ; Tables (2)

Coarse aggregates; Concrete; Deterioration; Diffraction; Dolomite; Durability; Forecasting; Iron; Pavements; Pores; Portland cement concrete; Quarries; Service life; Sodium chloride; Sodium chloride; Test procedures; X rays

Pores; Rapid methods; X-ray diffraction

Design; Geotechnology; Highways; Materials; Pavements; I32: Concrete; I36: Aggregates

TRIS, TRB

Dec 31 1987 12:00AM

• A NEW PROCESS FOR THE LAYING OF MONOLITHIC COMPOSITE CONTINUOUSLY REINFORCED CONCRETE PAVEMENTS
• COMPARISON OF CONCRETE PAVEMENT REHABILITATION TECHNIQUES IN OHIO DEMONSTRATION PROGRAM
• CONSTRUCTION OF A THIN-BONDED PORTLAND CEMENT CONCRETE OVERLAY IN SOUTH DAKOTA
• DRAINCRETE IN PAVEMENT REHABILITATION
• EARLY AGE PROPERTIES OF MAGNESIUM PHOSPHATE-BASED CEMENTS UNDER VARIOUS TEMPERATURE CONDITIONS
• EARLY STRENGTH OF CONCRETE PATCHING MATERIALS AT LOW TEMPERATURES
• FIELD EVALUATION OF CONCRETE PAVEMENT CONSOLIDATION
• FIELD EVALUATION OF DOWEL PLACEMENT IN CONCRETE PAVEMENTS
• FIELD PERFORMANCE OF BONDED CONCRETE OVERLAYS
• MOISTURE RETENTION TESTS AND AGITATION FOR MEMBRANE-FORMING CURING COMPOUNDS FOR PORTLAND CEMENT CONCRETE
• MONTANA'S EXPERIENCE WITH AND STRATEGIES FOR CONCRETE PAVEMENT REHABILITATION
• PERFORMANCE OF STEEL FIBER REINFORCED CONCRETE USING LARGE AGGREGATE
• PETROLOGICAL STUDIES ON CARBONATE AGGREGATE RESPONSIBLE FOR PAVEMENT D-CRACKING IN SOUTHERN MANITOBA, CANADA
• SULFATE IMPURITIES FROM DEICING SALT AND DURABILITY OF PORTLAND CEMENT MORTAR