DURABILITY OF CONCRETE CONSTRUCTION

A BRIEF DISCUSSION IS PRESENTED OF THE PRINCIPAL FEATURES OF THE NATURE OF CONCRETE WHICH ARE OF IMPORTANCE IN DEVELOPING ITS DURABILITY. THE GREATEST DURABILITY PROGRESS SEEMS TO HAVE BEEN MADE IN CONNECTION WITH THE CEMENTITIOUS MATRIX OF CONCRETE, THE HARDENED CEMENT PASTE. IT SEEMS THAT SOMEWHAT LESS SUCCESS HAS BEEN EXPERIENCED IN SOLVING PROBLEMS OF AGGREGATES. THE DURABILITY OF CONCRETE IN VARIOUS CIRCUMSTANCES IS DETERMINED VERY LARGELY BY THE PHYSICAL AND CHEMICAL NATURE OF ITS COMPONENT PARTS. AN INTENSIVE DISCUSSION IS PRESENTED OF VOIDS SPACE, INCLUDING ENTRAPPED AIR BUBBLES, CAPILLARY CAVITIES, CEMENT GEL AND MACROPORES WHICH LEADS TO THE DISCUSSION OF POROSITY OF VARIOUS AGGREGATES, AND THE PERMEABILITY OF ACCEPTABLE AGGREGATES. IT IS SHOWN THAT THE SMALLER VOID SPACES IN AGGREGATE, LIKE THE CAPILLARIES IN CEMENT PASTE CAN, UNDER CERTAIN CIRCUMSTANCES, BECOME PARTIALLY OR WHOLLY FILLED WITH WATER. FREEZING OF THIS WATER CAN HAVE IMPORTANT CONSEQUENCES FOR THE DURABILITY OF AGGRETATE. THE DETERIORATION OF CONCRETE IN FREEZING AND THAWING CAUSED BY THE FREEZING OF WATER THEREIN IS DESCRIBED EXTENSIVELY. TABLES ARE PRESENTED ILLUSTRATING THE RESULTS OF CONTROLLED TESTS OF THE FREEZING BEHAVIOR. THE ROLE OF ENTRAINED AIR IN THIS DETERIORATION PROCESS IS DISCUSSED AND IT IS CONCLUDED THAT ENTRAINED AIR HAS LITTLE INSTRINSIC EFFECT ON THE ABSORPTION OR PERMEABILITY OF CONCRETE. THE FREEZING OF FRESH CONCRETE AND THE FROST RESISTANCE AFFORDED BY ENTRAINED AIR IS ILLUSTRATED, TOGETHER WITH TEST PROCEDURES FROM FROST RESISTANCE AND FREEZING AND THAWING TESTS OF CONCRETE. FIVE DIFFERENT TYPES OF CEMENT ARE DESCRIBED IN RELATION TO THE PROBLEMS OF FREEZING AND THAWING. DETERIORATION OF CONCRETE IN PAVEMENTS BRIDGES, AND OTHER STRUCTURES, DUE TO EXPANSIVE REACTION BETWEEN CONSTITUENTS OF SOME AGGREGATE AND ALKALIES FROM CEMENTS IS DISCUSSED. PHOTOGRAPHS SHOWING ADVANCED CASES OF CRACKING CONCRETE STRUCTURES CAUSED BY ALKALI-SILICA REACTION, AS WELL AS METHODS FOR AVOIDING ALKALI-SILICA EXPANSION ARE SHOWN AND DISCUSSED.

• Supplemental Notes:
  • Monograph NO 4, 190 PP
• Corporate Authors:

  American Concrete Institute (ACI)

  38800 Country Club Drive
  Farmington Hills, MI  United States  48331
• Authors:
  • WOODS, H
• Publication Date: 1968

Subject/Index Terms

• TRT Terms: Air voids; Alkali aggregate reactions; Capillaries; Cement; Concrete; Concrete aggregates; Concrete construction; Cracking; Durability; Entrained air; Expansion; Freeze thaw durability; Freeze thaw tests; Gels; Moisture content; Permeability; Porosity
• Uncontrolled Terms: Concrete cracking
• Old TRIS Terms: Air voids content; Freezing thawing effects
• Subject Areas: Construction; Highways; Materials;

Filing Info

• Accession Number: 00213815
• Record Type: Publication
• Source Agency: Am Concrete Inst Journal & Proceedings
• Files: TRIS
• Created Date: Oct 13 1970 12:00AM