SHRINKAGE-COMPENSATED CEMENT AND THE READY-MIXED CONCRETE PRODUCER

This paper is concerned with a study of extending delivery times of ready-mixed concrete using shrinkage-compensated cement. It is pointed out that, particularly at higher temperatures, shrinkage-compensated cements have a tendency to lose slump rapidly and need retempering water which reduces strength, expansive potential and may increase drying shrinkage. An account is given of research carried out by the us national ready mixed concrete association to study the effect of temperature, batching procedure and retempering on mixing water requirement and restrained expansion; brief details are given of the work done to relate strength to neutron count measurements. This is followed by the results of analysis of field data from member companies, which show the relation between temperature and strength, the effect of temperature on mixing water requirement and the relation between expansion and cube strength. The use of water-reducing and retarding admixtures in shrinkage-compensated concretes is discussed. It is concluded that delivery time can be extended in hot weather by loading the cement on top of damp aggregate and delaying mixing until arrival on the job, that the use of ice can be helpful, but is not as good as layer loading on long-hauls, and that prolonged mixing and retempering significantly reduces potential expansion. The remainder of the paper is concerned with recommendations for the ready-mixed concrete producer and the cement producer. /TRRL/

• Corporate Authors:

  Quarry Managers Journal Limited

  62-64 Baker Street
  London W1M 2BN,   England 
• Authors:
  • Gaynor, R D
• Publication Date: 1973-7

Language

• English

Media Info

• Features: Figures; References;
• Pagination: p. 139-144
• Serial:
  • Cement, Lime and Gravel
  • Volume: 48
  • Issue Number: 7

Subject/Index Terms

• TRT Terms: Admixtures; Cement; Delivery service; Expansion; Expansive cement; Mixing; Plasticizers; Ready mixed concrete; Retarders (Chemistry); Retarders (Concrete); Shrinkage; Strength of materials; Temperature; Time; Water; Water consumption
• Uncontrolled Terms: Batching
• Geographic Terms: United States
• Old TRIS Terms: Mixing water; Retarder; Retempering /concrete/; Water requirements
• ITRD Terms: 4758: Cement; 284: Delivery; 6720: Expansion; 4715: Mixing water (concrete); 4725: Plasticizer; 4770: Ready mixed concrete; 4727: Retarder (concrete); 4743: Shrinkage; 5544: Strength (mater); 6722: Temperature; 5414: Time; 8122: USA
• Subject Areas: Highways; Materials; Planning and Forecasting; I32: Concrete; I72: Traffic and Transport Planning;

Filing Info

• Accession Number: 00097978
• Record Type: Publication
• Source Agency: Transport and Road Research Laboratory (TRRL)
• Files: ITRD, TRIS
• Created Date: Oct 18 1975 12:00AM