HARDENING OF LIGHTWEIGHT CONCRETE CONTAINING NATURAL AGGREGATES AT TEMPERATURES BELOW FREEZING POINT /IN RUSSIAN/

A COMPARATIVE STUDY IS DESCRIBED OF THE COMPRESSIVE STRENGTH OF LIGHTWEIGHT CONCRETE SAMPLES (DENSITY 1.45) CONTAINING POROUS MATERIALS MAINTAINED AT NORMAL TEMPERATURE, AT - 5 DEGREES C, AND AT - 20 DEGREES C, FOR 1, 7, 28 AND 90 DAYS. COMPRESSION TESTS WERE CARRIED OUT AS SOON AS THE SAMPLES WERE TAKEN OUT OF THE REFRIGERATOR, AND AT VARIOUS INTERVALS DURING THAWING. RESULTS WERE COMPARED TO THOSE OBTAINED WITH STANDARD DENSITY CONCRETE. CONCLUSIONS REACHED ARE AS FOLLOWS: DURING THE FREEZING OF YOUNG LIGHTWEIGHT CONCRETE, THE FREEZING POINT OF WATER IS LOWERED ENABLING THE INITIAL STRUCTURE OF THE CEMENT PASTE TO TAKE FORM; AFTER THAWING THE STRENGTH OF LIGHTWEIGHT CONCRETE IS RELATIVELY HIGHER THAN THAT OF HIGH-DENSITY CONCRETE. WATER ABSORPTION BY POROUS AGGREGATES CONTRIBUTES TO A DECREASE IN THE QUANTITY OF THE INTERSTITIAL WATER IN THE CEMENT PASTE AT THE TIME OF FREEZING; THERE IS NO PRESSURE CAUSED BY ICE IN THE CONCRETE DURING THE HARDENING PROCESS. ACCEPTED THEORIES ON CRITICAL STRENGTH ARE MODIFIED SINCE, AFTER FREEZING AT ANY AGE FOLLOWED BY CURING AT 20 DEGREES C FOR 28 OR 90 DAYS, THE STRENGTH SPECIFIED FOR THE CATEGORY OF CONCRETE STUDIED IS REACHED. THERE IS A RELATION BETWEEN CONCRETE STRENGTH AND THE POROSITY AND WATER ABSORPTION CAPACITY OF AGGREGATES. /LCPC/RRL/

• Supplemental Notes:
  • No 3, pp 20-22, 4 FIG
• Authors:
  • Mironov, S A
  • Saakyan, M O
• Publication Date: 1969

Media Info

• Serial:
  • Beton I Zhelezobeton /Ussr/

Subject/Index Terms

• TRT Terms: Compression tests; Compressive strength; Concrete curing; Freezing; Lightweight concrete; Natural aggregates; Porous materials; Thaw; Water
• Old TRIS Terms: Compressive strength tests
• Subject Areas: Highways; Materials;

Filing Info

• Accession Number: 00213052
• Record Type: Publication
• Source Agency: Road Research Laboratory /UK
• Files: TRIS
• Created Date: May 16 1971 12:00AM