Effect Of Retempering With Superplasticizer Admixtures On Slump Loss And Compressive Strength Of Concrete Subjected To Prolonged Mixing

The slump loss of fresh concrete at the construction site is one of the primary rheological properties responsible for the strength and durability aspects of concrete. Slump loss is defined as the loss of consistency of concrete with mixing time. Thus, slump loss has to be compensated somehow at the construction site so that concrete could be placed and compacted properly. This article reports on a study in which ASTM C 494 Type F superplasticizer was used for retempering concrete to restore its initial slump. In the study, concrete mixes having an initial slump of about 19 cm were prepared and subjected to prolonged mixing with different mixing duration (30, 60, 90, 120, and 150 min) following an initial mixing of 5 min to ensure homogeneity. At the end of each mixing period, cube specimens of 15 cm were cast from concrete retempered to its initial slump level and tested at the age of 28 days for compressive strength. The results revealed that those retempered with a superplasticizer admixture yielded significantly higher strength regardless of the mixing duration. The authors also comment that a mixing period of 90 min seems to be a turning point with regard to proper placement, compaction, and subsequent operations of concrete, regardless of the use of admixtures.

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/00088846
• Authors:
  • Erdogdu, Sakir
• Publication Date: 2005-5

Language

• English

Media Info

• Media Type: Print
• Features: Figures; References; Tables;
• Pagination: pp 907-912
• Serial:
  • Cement and Concrete Research
  • Volume: 35
  • Issue Number: 5
  • Publisher: Elsevier
  • ISSN: 0008-8846
  • Serial URL: http://www.sciencedirect.com/science/journal/00088846

Subject/Index Terms

• TRT Terms: Admixtures; Compressive strength; Concrete; Hydration; Rheological properties; Slump test; Superplasticizers; Workability
• Uncontrolled Terms: Retempering; Slump loss
• Subject Areas: Highways; Materials; I32: Concrete;

Filing Info

• Accession Number: 01001296
• Record Type: Publication
• Files: TRIS
• Created Date: Jun 28 2005 9:49AM