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CON 122 Session 2 - Standards and Specifications
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CON 122 Session 2 - Standards and Specifications

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CON 122 Session 2 - Standards and Specifications CON 122 Session 2 - Standards and Specifications Presentation Transcript

  • CON 122Concrete AdmixturesSession 2Standards and Specifications
  • Concrete Admixture Definition“A material other thanwater, aggregates, hydraulic cement, and fiberreinforcement used as an ingredient of concreteand mortar added to the batch before or duringits mixing.”
  • Types of Concrete Admixtures Chemical Admixtures Air-entraining Admixtures Calcium Chloride Admixtures for Flowing Concrete Specific Special Performance Admixtures
  • Liquid Admixture Standards and Specifications Description Standards / SpecificationsWater-reducing and set-controlling • ASTM C494admixtures • AASHTO M 194 • ASTM C 260Air-entraining admixtures • AASHTO M 154 • ASTM D 98Calcium Chloride • AASHTO M 144Admixtures for Flowing Concrete • ASTM C 1017Specific Performance Admixtures • ASTM C 494
  • Standard Specification for Chemical Admixtures for Concrete Type A – Water-reducing admixtures Type B – Retarding admixtures Type C – Accelerating admixtures Type D – Water-reducing and retarding admixtures Type E – Water-reducing and accelerating admixtures Type F – Water-reducing, high range admixtures Type G – Water-reducing, high range, retarding ASTM Designation: C 494/C 494M - 99ϵ1
  • Low water to cement ratio concrete with low chloridepermeability—easily made with high-range water reducers.
  • Chemical Admixtures Effect Concrete Properties Workability Durability Economics Increase/decrease set time Accelerate strength gain Control Temperature Gain Special Attributes
  • Chemical Admixtures Dosage Types A, B, and D (2 to 7 oz/100 lbs cementitious material)  Normal dosage: 5-8% water reduction; Type B and D retard set Types C and E  Normal dosage will accelerate set Types F and G (High-range superplastizers)  High dosage at 10-90 oz/100 lbs cementitious material: 12- 25% water reduction  Retards set
  • ASTM C 494 Physical Testing Requirements ASTM Designation: C 494/C 494M - 99ϵ1
  • ASTM C 260 Air-Entraining Admixtures 1. Scope*  1.1 This specification covers materials proposed for use as air-entraining admixtures to be added to concrete mixtures in the field. 3.1.1. air-entraining admixture, n – for the purpose of this specification, a material that is used as an ingredient of concrete, added to the batch immediately before or during its mixing, for the purpose of entraining air. ASTM Designation: C 260 - 01
  • Physical Requirements for Air- Entraining Admixtures ASTM Designation: C 260 - 01
  • Effects of Using Air-Entraining Admixture Lubrication Effect of air bubbles Reduction of mixing water for equal slump Improved workability Causes sticky finishability
  • Concrete Producer Adjustments Aggregate Characteristics Proportions of concrete constituents Type and duration of mixing Consistency Temperature Cementitious Materials
  • Use of Calcium Chloride Accelerate Set Time Induces Corrosion of Metals Aggravate effects of poor quality construction
  • Use of Calcium Chloride
  • Consequences of Corrosion in Concrete Cracking Spalling
  • Corrosion of embedded steelreinforcement is the #1 cause ofpremature deterioration ofconcrete infrastructure in NorthAmerica (and many other regionsworldwide). 17
  • Calcium Chloride D 98 Requirements
  • ASTM C 1017 Flowing Concrete Mixtures 1. Scope  1.1 This specification covers two types of chemical admixtures to be added to hydraulic cement concrete mixtures for the purpose of producing flowing concrete. The types are as follows:  1.1.1. Type I – Plasticizing  1.1.2. Type II – Plasticizing and retarding ASTM Designation: C 1017/ C 1017M
  • ASTM C 1017 Flowing Concrete Admixtures ASTM Designation: C 1017/ C 1017M
  • New Specific Performance Admixture, Type S Type S, has been added to C 494/ C 494M For admixtures that provide primary specific performance benefits to concrete Other than water reduction, strength, or modification of time of set.
  • Special Specific Performance Admixtures, Type S