Title:
Suggested Modifications to ASTM C31 for Consolidation by Rodding (Prepublished)
Author(s):
Paige Toebben, Kyle Riding, Ahmed Abd El Fattah, Dimitri Feys
Publication:
Materials Journal
Volume:
Issue:
Appears on pages(s):
Keywords:
ASTM C31; compressive strength; concrete; consolidation; density; field specimens; rodding
DOI:
10.14359/51749124
Date:
8/19/2025
Abstract:
ASTM C31 describes the procedure for making concrete specimens in the field. Its origin can be traced to 1920, proposing rodding or stroking each 100 mm thick layer 25-30 times. Concrete technology has evolved tremendously over the last century, but specimens are still prepared following this 100-year-old methodology. This paper investigates the density and compressive strength of concrete cylinders for different consolidation procedures. Mix design variations include paste volume, w/c, aggregate grain size distribution, fly ash, and plasticizer. An increase in compressive strength of approximately 5 MPa can be obtained if 100 × 200 mm cylinders are rodded in 4 layers, 25 rods each, if the slump is not over 100 mm. For all other mixtures, the current rodding procedure of 2 layers, 25 rods each, is recommended. For mixtures with higher slump, 2 layers with less rodding per layer deliver similar strength values, but the variability is high.