CTRE is an Iowa State University center, administered by the Institute for Transportation.

Address: 2711 S. Loop Drive, Suite 4700, Ames, IA 50010-8664

Phone: 515-294-8103
FAX: 515-294-0467

Website: www.ctre.iastate.edu/

Iowa State University--Becoming the Best

Improving Variability and Precision of AVA Test Results and Developing Rational Specification Limits

Researcher(s)

Principal investigators:

Co-principal investigators:

Student researchers:

Project status

Completed

Start date: 10/26/06
End date: 06/30/08

Publications

Report: Improving Variability and Precision of AVA Test Results and Developing Rational Specification Limits (1.6 mb pdf) June 2008

Tech transfer summary: Improving Precision and Variability of Air-Void Analyzer Test Results (130 kb pdf) Dec 2008

Sponsor(s)/partner(s)

Sponsor(s): Federal Highway Administration

About the research

Abstract: Since air-void analyzer (AVA) was introduced in the 1990s, various studies have been conducted in the United States to apply this technology. Many concerns are raised on (a) the variation of the AVA tests, (b) the relationship between AVA and other standard measurements, and (c) AVA specification limits. The application of AVA tests in concrete practice is therefore very challenging. The goals of the present research project are to reduce variability and improve precision of AVA test results and to develop rational specification limits for controlling concrete freezing and thawing (F-T) damage using the AVA test parameters.

This project consists of three phases: Phase 1: Literature search and analysis of existing AVA data (June 2007--August 2008) Phase 2: AVA testing procedure and specification modification Phase 3: Field study of AVA and specification refinement

In the present research report, the major activities and findings of the Phase 1 study are presented, and the major tasks for the Phase 2 study are recommended.

The major activities of the Phase 1 study included the following: performing a literature search, collecting and reviewing available AVA data, completing a statistical analysis on collected AVA data, and carrying out some AVA trial tests in lab. The results indicate that AVA is a time- and cost-effective tool for concrete quality control. However, robustness of the AVA equipment, test procedures, and resulting interoperations need further improvement for a proper implementation of the AVA technology in concrete practice.