WINTER DAMAGE ON ROADS (GERMAN)

AFTER A DESCRIPTION OF THE DAMAGE TO CONCRETE AND BITUMINOUS ROAD SURFACES BY THAWING SALT AND STEEL STUDDED TYRES, THE CAUSES OF THE DAMAGE ARE EXPLAINED. THAWING SALTS DO NOT REACT CHEMICALLY IN CONCRETE SURFACES (PERHAPS THROUGH THE FORMATION OF DOUBLE SALTS) BUT PHYSICALLY THROUGH FREEZING OF THE PORE WATER AND DILATING THE ICE. BECAUSE THE SALT CONCENTRATION DECREASES WITH THE LAYER THICKNESS, THE BOTTOM LAYERS FREEZE UP FIRST OF ALL. THEN AS SOON AS THE TOPMOST LAYERS FREEZE, THEY PULL AWAY FROM THE ALREADY FROZEN BOTTOM LAYER. ADDED TO THIS ARE THE STRESSES CAUSED BY THE SUDDEN DECREASE IN TEMPERATURE BROUGHT ABOUT BY THE MELTING OF THE SALTS. IN NO CASE MAY THE PROPORTION OF FINE SAND IN THE CONCRETE, AND THE WATER-CEMENT RATIO, BE TOO HIGH. THE AGGREGATE MUST COMPLETELY FULFIL THE REQUIREMENTS AND MAY NOT CONTAIN ANY PARTICLES WHICH ARE NOT RESISTANT TO FROST. WHEN AIR ENTRAINING AGENTS ARE ADDED EXTRA SPACE APPEARS ON THE CONCRETE. CURRENT EXAMINATION OF TOTAL AIR CONTENT IS A PART OF THE SPECIALIZED PRODUCTION OF CONCRETE SURFACES. INSUFFICIENT COATING OF THE AGGREGATES, PARTICLE DAMAGE CAUSED BY SPIKES OR REINFORCEMENT BY QUENCHING ARE CITED AS CAUSES OF FROST DAMAGE ON BITUMINOUS SURFACES. TESTS SHOWED THAT WITH 8,000 VEHICLES PER HOUR, 15 PER CENT OF THEM HAVING STEEL STUDDED TYRES, GROOVES 1,4 MM IN DEPTH CAN BE CUT INTO THE SURFACING IN ONE WINTER. IT IS THEREFORE NECESSARY TO USE SURFACINGS WITH BETTER MECHANICAL PROPERTIES AND HARDER AGGREGATES. /FG/RRL/

• Supplemental Notes:
  • Vol 20, No 35, PP 83-87, 12 REF
• Authors:
  • Schleicher, E
• Publication Date: 1966

Media Info

• Serial:
  • Bauwirtschaft
  • Publisher: Bauverlag

Subject/Index Terms

• TRT Terms: Aggregates; Air content; Bituminous materials; Bituminous pavements; Cold weather; Concrete pavements; Defects; Freezing; Frost damage; Operations; Pavement distress; Pavement layers; Pavements; Sodium chloride; Sodium chloride; Studded tires; Surface course (Pavements); Surface treating; Temperature
• Old TRIS Terms: Bituminous surfacing
• Subject Areas: Administration and Management; Geotechnology; Highways; Maintenance and Preservation; Materials; Pavements;

Filing Info

• Accession Number: 00218321
• Record Type: Publication
• Source Agency: Road Research Laboratory /UK
• Files: TRIS
• Created Date: Sep 8 1994 12:00AM