DELAYED EXPANSION OF CONCRETE DELIVERED BY PUMPING THROUGH ALUMINUM PIPELINE

THE VIRGINIA DEPARTMENT OF HIGHWAYS RECENTLY MODIFIED ITS SPECIFICATIONS TO ALLOW THE DELIVERY OF CONCRETE BY PUMPING WITH THE FOLLOWING RESTRICTIONS: PUMPING OF THE CONCRETE MAY BE APPROVED PROVIDED THE CONCRETE IS PUMPED THROUGH A CONDUIT SYSTEM OTHER THAN ALUMINUM. THE RESULTS ARE PRESENTED FROM OBSERVATIONS AND TESTS MADE ON THE DECK CONCRETE, ALONG WITH THOSE FROM SUBSEQUENT SPECIAL FIELD TRIAL USE IN BOTH ALUMINUM AND STEEL LINES TO DELIVER SEVERAL MIXTURES OF WIDELY VARYING MATERIALS AND PROPERTIES THAT CONFIRM THE ROLE OF ALUMINUM IN THE DETERIMENTAL EXPANSION. CONCRETE DELIVERED BY PUMPING THROUGH ALUMINUM PIPE WAS FOUND TO BE ADVERSELY AFFECTED BY A REACTION BETWEEN THE CEMENT PASTE AND THE ALUMINUM. THIS REACTION, WHICH GENERATES HYDROGEN GAS, CAUSES: AN EXPANSION OF CONCRETE, REDUCTION IN STRENGTH, REDUCTION IN RESISTANCE TO FREEZING AND THAWING, AND ERRATIC PERFORMANCE OF WATER- REDUCING RETARDERS. WHILE VARIATIONS IN MATERIALS MIGHT MITIGATE THE REACTION TO SOME DEGREE, THE REACTION OBSERVED WITH THE TWO WIDELY DIFFERENT CEMENTS, REGARDLESS OF THE PRESENCE OF A RETARDER, THE FAIRLY COMMON ADMIXTURE OF SEVERAL GRADATIONS, AND A WIDE RANGE OF SLUMP AND AIR CONTENT, SUGGEST THAT ELIMINATION OF THE PROBLEM BY MODIFICATION TO THE MIXTURE WOULD BE OF SECONDARY IMPORTANCE. THE DATA OBTAINED, AS WELL AS THE LITERATURE REVIEWED, SUGGESTS THAT THE LIME AS WELL AS THE MORE ACTIVE ALKALIES, SUCH AS SODIUM AND POTASSIUM, PARTICIPATE IN THE ACTION. THE EFFECTS ON SIGNIFICANT PHYSICAL PROPERTIES OF CONCRETE PLACED DURING THE DECK PLACEMENT ARE COMPLETELY EXPLAINED BY THE INCREASE IN VOID CONTENT. IN VIEW OF THESE CONCLUSIONS, IT IS RECOMMENDED THAT CONCRETE NOT BE PUMPED THROUGH ALUMINUM PIPE.

  • Supplemental Notes:
    • Concrete CaSE STUDY NO 20, 39 PP, 11 FIG, 12 TAB, 17 REF,
  • Corporate Authors:

    Virginia Highway Research Council

    Charlottesville, VA  USA 
  • Authors:
    • Newlon, H
    • Ozol, M A
  • Publication Date: 1970-3

Subject/Index Terms

Filing Info

  • Accession Number: 00213802
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Oct 5 1970 12:00AM