Project Title: Design and Evaluation of High-Volume Fly Ash (HVFA) Concrete Mixes Report D: Creep, Shrinkage, and Abrasion Resistance of HVFA Concrete

The opinions, findings, and conclusions expressed in this publication are those of the principal investigators and the Missouri Department of Transportation. They are not necessarily those of the U.S. Department of Transportation, Federal Highway Administration. This report does not constitute a standard or regulation. ii ABSTRACT The main objective of this study was to determine the effect on shrinkage, creep, and abrasion resistance of high-volume fly ash (HVFA) concrete. The HVFA concrete test program consisted of comparing the shrinkage, creep, and abrasion performance of two concrete mix designs with 70% cement replacement with Class C fly ash relative to a Missouri Department of Transportation (MoDOT) standard mix design. Modified versions of standard test methods were used for the shrinkage and creep portions of the study. Shrinkage was measured through a modified version of ASTM C157 " Standard Test Method for Length Change of Hardened Hydraulic-Cement Mortar and Concrete, " while creep was measured through a modified version of ASTM C512 " Standard Test Method for Creep of Concrete in Compression. " Abrasion resistance was measured in accordance with ASTM C944 " Standard Test Method for Abrasion Resistance of Concrete or Mortar Surfaces by Rotating-Cutter Method. " In addition to comparisons between the three mix designs, the results were also compared to existing prediction models and previous research results on HVFA concrete. Both HVFA concrete mixes showed a significant decrease in shrinkage strain relative to the control concrete, which was very consistent with previous research. With regard to creep, both HVFA concrete mixes also showed improved performance over the control mix, again confirming previous research results. However, the control concrete exhibited improved abrasion resistance relative to the two HVFA concrete mixes, which coincided with the higher strength of the control mix. At later ages, the abrasion resistance of the HVFA concrete improved due to late age strength gain characteristic of this material.