EFFECT OF AGGREGATE TYPE ON THE PROPERTIES OF SHRINKAGE - COMPENSATING CONCRETE

EXPANSIVE CEMENT CONCRETES, IF ADEQUATELY RESTRAINED BY REINFORCING STEEL, CAN MINIMIZE OR PREVENT THE DEVELOPMENT OF CRACKS DUE TO DRYING SHRINKAGE. SUCH CONCRETES ARE REFERRED TO AS SHRINKAGE-COMPENSATING. REPORTED ARE RESULTS OF AN INVESTIGATION UNDERTAKEN TO DETERMINE THE EFFECT OF AGGREGATE TYPE ON THE PROPERTIES OF SHRINKAGE-COMPENSATING CONCRETES. INCLUDED IN THIS STUDY WERE 3 TYPES OF NATURAL AGGREGATES AND ONE LIGHTWEIGHT AGGREGATE. TWO TYPES OF CEMENT WERE USED. ONE WAS THE SHRINKAGE-COMPENSATING CEMENT THAT WAS A BLEND OF 15 PERCENT BY WEIGHT OF CALCIUM SULFOALUMINATE EXPANSIVE COMPONENT AND 85 PERCENT OF TYPE V PORTLAND CEMENT. THE SECOND CEMENT USED IN THE CONTROL CONCRETES WAS 100 PERCENT TYPE V PORTLAND CEMENT. THE EXPANSION AND SHRINKAGE CHARACTERISTICS OF THE SHRINKAGE-COMPENSATING CONCRETES WERE DETERMINED FOR BOTH RESTRAINED AND UNRESTRAINED PROSMS. COMPRESSIVE STRENGTH AND MODULUS OF ELASTICITY WERE DETERMINED FOR UNRESTRAINED CYLINDRICAL SPECIMENS. ALL CONCRETES HAD A CEMENT CONTENT OF 5.5 SCY AND A WATER-CEMENT RATIO OF 0.58 BY WEIGHT. WITH THESE FIXED MIX PROPORTIONS, THE SLUMP OF THE CONCRETES WITH THE 4 DIFFERENT TYPES OF AGGREGATE VARIED FROM 2 TO 4 IN. FROM THE RESULTS OF THIS INVESTIGATION IT IS CONCLUDED THAT THE AGGREGATE TYPE IS AN IMPORTANT FACTOR IN THE PROPERTIES OF A SKRINKAGE-COMPENSATING CONCRETE. SHRINKAGE-COMPENASTING CONCRETE MIXES MUST BE SO DESIGNED THAT THEIR RESTRAINED EXPANSION IS OF SUFFICIENT MAGNITUDE TO COMPENSATE FOR THE POTENTIAL SHRINKAGE OF THE CONCRETE CONTAINING A CERTAIN TYPE OF AGGREGATE. THE EXPANSION AND SHRINKAGE BEHAVIOR OF A SHRINKAGE-COMPENSATING CONCRETE IS RELATED TO ITS MODULUS OF ELASTICITY. CONCRETES OH HIGH ELASTIC MODULUS EXHIBIT A LARGER EXPANSION THAN DO CONCRETES OF LOWER MODULUS OF ELASTICITY. /AUTHOR/

• Record URL:
  http://onlinepubs.trb.org/Onlinepubs/hrr/1970/316/316-008.pdf
• Supplemental Notes:
  • Paper sponsored by Committee on Construction Practices--Flexible Pavement. 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.
• Authors:
  • Epps, Jon A
  • Polivka, Milos
• Publication Date: 1970

Media Info

• Media Type: Digital/other
• Features: Figures; References;
• Pagination: pp 82-90
• Monograph Title: Construction and construction equipment
• Serial:
  • Highway Research Record
  • Issue Number: 316
  • Publisher: Highway Research Board

Subject/Index Terms

• TRT Terms: Calcium compounds; Cement content; Compressive strength; Concrete pavements; Drying; Expansion; Expansive cement; Lightweight aggregates; Modulus of elasticity; Natural aggregates; Portland cement; Reinforcing steel; Shrinkage; Water cement ratio
• Old TRIS Terms: Expansive cement concrete pavement
• Subject Areas: Construction; Highways;

Filing Info

• Accession Number: 00215351
• Record Type: Publication
• Files: TRIS, TRB
• Created Date: Nov 9 1970 12:00AM