EFFECT OF MORTAR SATURATION IN CONCRETE FREEZING AND THAWING TESTS

THE RESULTS ARE PRESENTED OF LABORATORY FREEZING AND THAWING TESTS ON CONCRETE IN WHICH CERTAIN VARIABLES WERE CONTROLLED AS CLOSELY AS POSSIBLE SO THAT VARIATIONS IN DURABILITY COULD BE RELATED TO VARIATIONS IN THE WATER CONTENT AND AVAILABLE AIR SPACE IN THE MORTAR OR PASTE COMPONENT. A TOTAL OF 130 CONCRETE BEAMS FROM 31 BATCHES OF CONCRETE WERE TESTED. CHANGES IN WEIGHT AND UNIT WEIGHT WERE DETERMINED AT INTERVALS THROUGH THE COURSE OF CURING AND FREEZING AND THAWING. METHODS WERE DEVELOPED USING THESE DATA IN CALCULATING THE DEGREE OF SATURATION OF THE MORTAR PHASE OF THE CONCRETE IN CONNECTION WITH A SEMI-EMPIRICAL CALCULATION OF VOLUME CHANGE OF THE CEMENT+WATER COMPONENT, AND AN ESTIMATE OF FREEZABLE WATER BASED ON RELATIONSHIPS WITH THE "NONEVAPORABLE WATER CONTENT" OF THE CEMENT. IT IS CONCLUDED THAT CONCRETE SUBJECTED TO FREEZING AND THAWING WHEN THE MORTAR COMPONENT (OR PASTE-PLUS-AIR COMPONENT) HAS A DEGREE OF SATURATION OF 0.91 OR GREATER WILL DETERIORATE RAPIDLY; ALL SPECIMENS IN THIS RANGE SHOWED RAPID DETERIORATION. ALL SPECIMENS WITH DEGREE OF SATURATION BELOW 0.88 WERE HIGHLY DURABLE ALTHOUGH DETERIORATION IN THIS RANGE MAY BE CAUSED BY A VARIETY OF FACTORS SUCH AS EXPANSION OF INFERIOR AGGREGATES, DIFFERENTIAL THERMAL EXPANSION OF CONCRETE COMPONENTS, HYDRAULIC PRESSURE FROM RESISTANCE TO FLOW OF WATER, NON-UNIFORM DISTRIBUTION OF FREEZABLE WATER, OR ADVERSE CHEMICAL REACTIONS. INVESTIGATIONS OF FACTORS SUCH AS DIFFERENT CONCRETE MATERIALS OR ADMIXTURES SHOULD BE CONDUCTED WITH THE DEGREE OF SATURATION ON THE ORDER OF 0.80 SO THAT THE RESULTS CAN REFLECT THE INFLUENCE OF THE VARIABLE UNDER INVESTIGATION. A HIGH DEGREE OF SATURATION MAY OBSCURE ENTIRELY OTHER EFFECTS. THE LOWER DEGREE OF SATURATION IS CONVENIENTLY OBTAINED BY AIR ENTRAINMENT. OTHER CONCLUSIONS ARE DRAWN WITH REGARD TO WATER ABSORPTION IN AIR-ENTRAINED CONCRETE AND IN PARTIALLY-DRIED CONCRETE. /AUTHOR/

  • Supplemental Notes:
    • Vol 30, pp 204-216, 3 FIG, 9 TAB, 18 REF
  • Authors:
    • Whiteside, T M
    • SWEET, H S
  • Publication Date: 1951

Media Info

  • Monograph Title: Proceedings of the Thirtieth Annual Meeting of the Highway Research Board Held at Washington, D.C., January 9-12, 1951
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00213947
  • Record Type: Publication
  • Files: TRIS, TRB
  • Created Date: Jul 25 1971 12:00AM