THE AE-55 INDICATOR FOR AIR IN CONCRETE

THE AE-55 AIR INDICATOR OR CHACE AIR METER, A POCKET-SIZED DEVICE INTENDED FOR USE IN THE FIELD TO ESTIMATE THE AIR CONTENT OF PLASTIC CONCRETE IS ANALYZED. TESTS WERE CONDUCTED TO OBTAIN INFORMATION ON THE ACCURACY AND DEPENDABILITY OF THE APPARATUS. THE AIR CONTENT OF A LARGE NUMBER OF CONCRETE MIXES PREPARED IN THE LABORATORY WAS DETERMINED USING THIS INDICATOR. THE AIR INDICATOR CONSISTS OF TWO PARTS: A SMALL CYLINDER OF PYREX GLASS WHICH TAPERS TO A STEM OR TUBE ABOUT 1/4 INCH IN DIAMETER AND 3 INCHES IN LENGTH, AND A RUBBER STOPPER WITH A BRASS CUP MOUNTED ON THE SMALLER END. THE STOPPER FITS THE LARGER END OF THE GLASS CYLINDER. THE BRASS CUP IS FILLED WITH MORTAR FROM THE CONCRETE. THE CYLINDER WAS FILLED WITH DENATURED ALCOHOL AND THE STOPPER AND CUP WERE INSERTED INTO THE CYLINDER. THE INDICATOR WAS INVERTED, AND THE STOPPER PRESSED FIRMLY INTO THE CYLINDER. WHEN ALL OF THE MORTAR IS DISPERSED INTO THE ALCOHOL AND NO AIR BUBBLES REMAIN, THE INDICATOR IS HELD IN A VERTICAL POSITION AND THE NEW LEVEL OF THE ALCOHOL READ TO THE NEAREST HALF GRADATION ON THE GRADUATED STEM. THIS VOLUMETRIC METHOD IS SIMILAR TO ASTM METHOD C173. IT IS CONCLUDED THAT THIS INDICATOR IS AN APPARATUS OF CONSIDERABLE MERIT TO DETERMINE THE APPROXIMATE AIR CONTENT OF CONCRETE IN THE FIELD, PROVIDING THE AMOUNT OF MORTAR IN THE CONCRETE IS KNOWN. AT LEAST THREE TESTS SHOULD BE MADE FOR EACH DETERMINATION OF AIR CONTENT BECAUSE OF THE SMALL AMOUNT OF MORTAR USED IN THE TEST. THE METHOD IS NOT CONSIDERED SUITABLE AS A REPLACEMENT OF THE PRESSURE OR GRAVIMETRIC METHODS FOR DETERMINATION OF AIR CONTENT OF CONCRETE, BUT IS USEFUL AS A SUPPLEMENTARY TEST.

Media Info

  • Monograph Title: Instrumentation for measuring characteristics of concrete
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00213255
  • Record Type: Publication
  • Files: TRIS, TRB
  • Created Date: Sep 16 1994 12:00AM