WATER-REDUCING RETARDERS FOR CONCRETE--CHEMICAL AND SPECTRAL ANALYSES

THE PURCHASER OF A CONCRETE RETARDER IS PRIMARILY INTERESTED IN THE PERFORMANCE OF THE MATERIAL AND HIS INITIAL EVALUATION IS BASED ON TESTS TO SHOW THE EFFECT OF THE MATERIAL ON CONCRETE. HE MUST, HOWEVER, ASSURE HIMSELF THAT THE COMPOSITION OF EACH LOT PURCHASED HAS NOT BEEN MATERIALLY ALTERED SUBSEQUENT TO HIS INITIAL ACCEPTANCE OF THE PRODUCT. TO EXPLORE THE BEST MEANS OF DOING THIS, CHEMICAL AS WELL AS ULTRAVIOLET AND INFRARED SPECTRAL ANALYSES WERE MADE ON 25 COMMERCIAL RETARDERS. THE RESULTS ARE REPORTED IN THIS ARTICLE. THESE MATERIALS WERE FOUND TO BE OF THREE GENERAL TYPES: LIGNOSULFONATES, SALTS OF HYDROXY-CARBOXYLIC ACIDS, AND CARBOHYDRATES. IT WAS FOUND THAT INFRARED SPECTRAL ANALYSIS OFFERS THE MOST PROMISING AND RAPID MEANS OF CLEARLY IDENTIFYING SUCH PRODUCTS. ULTRAVIOLET TECHNIQUES WERE ALSO FOUND TO BE OF VALUE IN IDENTIFYING LIGNOSULFONATE RETARDERS AND IN ESTABLISHING THE CONCENTRATION OF THE MAJOR ACTIVE INGREDIENT. CONVENTIONAL CHEMICAL PROCEDURES, ALTHOUGH USEFUL, WERE TEDIOUS AND TIME- CONSUMING, AND OFTEN YIELDED EMPIRICAL OR DOUBTFUL RESULTS FOR CERTAIN MAJOR ORGANIC CONSTITUENTS. /AUTHOR/

Media Info

  • Monograph Title: Tests and investigations of retarding admixtures for concrete
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00212641
  • Record Type: Publication
  • Files: TRIS, TRB
  • Created Date: Aug 5 1994 12:00AM