00217432

Monograph

http://onlinepubs.trb.org...ubs/nchrp/nchrp_rpt_15.pdf

A SEARCH WAS MADE FOR A TEST OR TESTS THAT WOULD RAPIDLY AND RELIABLY IDENTIFY AGGREGATE PARTICLES SUBJECT TO DESTRUCTIVE VOLUME CHANGE WHEN FROZEN IN CONCRETE. THE TEST METHODS INVESTIGATED WERE' /1/ THE POWERS SLOW FREEZE-THAW OF CONCRETE SPECIMENS, /2/ AGGREGATE PORE SYSTEM STUDIES, /3/ AGGREGATE PARTICLE EXPANSION STUDIES, AND /4/ PETROGRAPHIC EXAMINATION. THE METHOD PROPOSED BY POWERS FOR PREDICTING THE FROST RESISTANCE OF CONCRETE WAS FOUND TO EXPLAIN THE OBSERVED PHENOMENA RELATED TO FROST ACTION IN CONCRETE. EXPANSION OF INDIVIDUAL AGGREGATE PARTICLES DURING FREEZING CORRELATED SIGNIFICANTLY WITH RAPID FREEZE- THAW DURABILITY ACTORS AND WITH DILATION OF CONCRETE SPECIMENS CONTAINING THE AGGREGATES. THE PORE STUDIES EXAMINED THE POROSITY, PERMEABILITY, AND CAPILLARITY OF A VARIETY OF AGGREGATES AND A HARDENED MORTAR. PETROGRAPHIC ANALYSES EXPLAINED AND PREDICTED THE BEHAVIOR OF THE TEST AGGREGATES IN FREEZE-THAW TESTING. PETROGRAPHY ALONE, HOWEVER, CANNOT ISOLATE ALL POSSIBLE EFFECTS OF THE SEVERAL POTENTIALLY DELETERIOUS FEATURES IN MOST AGGREGATES. A SINGLE PROCEDURE THAT POSSESSES ALL OF THE DESIRED ATTRIBUTES OF SPEED, SIMPLICITY, AND ABILITY TO DISCRIMINATE BY DEGREE WAS NOT DISCOVERED.

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. No 15, pp 1-66, FIG, TAB, REF

1965

NCHRP Report

Digital/other

Aggregates; Capillarity; Concrete; Durability; Expansion; Freeze thaw tests; Frost action; Frost susceptibility; Geological surveying; Identification systems; Permeability; Petrography; Porosity; Test procedures; Volume changes

Identification

Geotechnology; Highways

TRIS, ATRI

Nov 18 1994 12:00AM