Comparison of Setting Time Measured Using Ultrasonic Wave Propagation With Saw-Cutting Times on Pavements in Iowa

The mission of the National Concrete Pavement Technology Center is to unite key transportation stakeholders around the central goal of advancing concrete pavement technology through research, tech transfer, and technology implementation. The contents of this report reflect the views of the authors, who are responsible for the facts and the accuracy of the information presented herein. The opinions, findings and conclusions expressed in this publication are those of the authors and not necessarily those of the sponsors. The sponsors assume no liability for the contents or use of the information contained in this document. This report does not constitute a standard, specification, or regulation. The sponsors do not endorse products or manufacturers. Trademarks or manufacturers' names appear in this report only because they are considered essential to the objective of the document. Federal and state laws prohibit employment and/or public accommodation discrimination on the basis of age, color, creed, disability, gender identity, national origin, pregnancy, race, religion, sex, sexual orientation or veteran' s status. If you believe you have been discriminated against, please contact the Iowa Civil Rights Commission at 800-457-4416 or the Iowa Department of Transportation affirmative action officer. If you need accommodations because of a disability to access the Iowa Department of Transportation' s services, contact the agency' s affirmative action officer at 800-262-0003. 16. Abstract Concrete setting behavior strongly influences scheduling of construction operations, such as surfacing, trowelling, jointing, and saw-cutting. To conduct pavement sawing activities effectively, it is useful for contractors to know when a concrete mixture is going to reach initial set, or when the sawing window will open. Monitoring the set time of a fresh mixture also provides a tool to assess the uniformity between material and concrete batches. The aim of this project was to confirm that initial set could be measured using an ultrasonic pulse velocity (UPV) approach, and to assess whether there was a relationship between initial set and sawing time for pavement concrete in the field. Eight construction sites were visited in Iowa over a single summer/fall period. At each site, initial set was determined using a p-wave propagation technique with a commercial device. It was also determined on mortar samples in accordance with ASTM C 403. Calorimetric data were collected using a commercial semi-adiabatic device on some of the sites. The data collected to date revealed the following:  UPV approaches appear to be able to report initial set …