Effective Field Use of High-range, Water-reduced Concrete: Final Report

About the report:

This report describes the experience of the Virginia Department of Highways and Transportation with the use of high range, water reduced (HRWR) concrete. A description of the installation of the HRWR concrete in two pavements and four bridge decks, along with the results of evaluative tests, is given in Appendix A. Appendix B details the evaluations of HRWR concretes prepared in the laboratory at the Research Council. Based on the field and laboratory experience, recommendations concerning the further use of HRWR concrete by the Virginia Department of Highways and Transportation were formulated. As noted in Appendix A, on the average the HRWR concrete placed in the field with conventional equipment was properly consolidated and controlled. However, because of the unanticipated variability of the concrete, portions of the concrete exhibited inadequate consolidation, segregated mixture components, improperly entrained air, shrinkage cracks, and poor finishes. Also, specimens subjected to cycles of freezing and thawing showed low durability factors that were attributed to an unsatisfactory air void system. As noted in Appendix B, subsequent laboratory work revealed that HRWR admixtures satisfied the requirements of ASTM C494. On the basis of the results of the laboratory work, explanations were developed for the problems that occurred in the field.

Authors