Title:
Development of Modified Double-Punch Test for Quality-Control Testing of UHPC Tensile Performance
Author(s):
Megan S. Voss, Daniel Alabi, Raid S. Alrashidi, Taylor A. Rawlinson, Christopher C. Ferraro, H. R. Hamilton, Joel B. Harley, and Kyle A. Riding
Publication:
Symposium Paper
Volume:
363
Issue:
Appears on pages(s):
38-59
Keywords:
tensile testing, UHPC, double-punch, fiber-reinforced, toughness, quality control
DOI:
10.14359/51742106
Date:
7/1/2024
Abstract:
The movement of ultra-high-performance concrete (UHPC) toward wide scale acceptance within the concrete industry has generated interest in developing improved test methods to provide quality assurance for this material. Most test methods currently used to measure the tensile behavior of ultra-high-performance concrete require specialized testing equipment that is not typically owned by precast or ready-mix production facilities. These test methods provide reliable data for quality assurance of newly developed concrete mixes, but they are impractical as quality-control tests, which would need to be performed for every UHPC placement. This paper presents the development of a simple and inexpensive test to measure tensile strength and ductility for UHPC and serve as a quality-control test. This method was developed from the double-punch test, commonly referred to as the “Barcelona test,” but has been revised to incorporate substantial changes to the loading and data collection requirements to eliminate the need for expensive, specialized equipment. It was determined that the modified test method could produce reliable results using a load-controlled testing procedure with manually recorded data points taken every 0.635 mm (0.025 inches) of vertical displacement for ductile concrete specimens. It was also determined that specimen surface grinding, loading rate, and punch alignment did not significantly influence the test results. However, the fabrication of the specimens, specifically the rate and method at which the molds were filled, had a significant effect on the results. Accordingly, any recommended standardized test method based off of this procedure should have requirements on specimen fabrication.