Title:
Evaluation of AASHTO T 397: Standard Method of Test for Uniaxial Tensile Response of Ultra-High-Performance Concrete
Author(s):
Sahith Gali and Sri Sritharan
Publication:
Materials Journal
Volume:
121
Issue:
1
Appears on pages(s):
105-118
Keywords:
AASHTO T 397; direct tensile test; fiber volume; multicracking; tensile behavior; ultra-high-performance concrete (UHPC)
DOI:
10.14359/51739204
Date:
1/1/2024
Abstract:
Ultra-high-performance concrete (UHPC) is a cementitious
concrete material known for its sustained post-cracking tensile
performance. Various specimen geometries and different test
approaches have been used to establish the tensile characteristics
of UHPC. Intending to standardize a direct tension test method,
this paper independently evaluates a procedure developed by the
Federal Highway Administration (FHWA), which has been adopted
into AASHTO T 397. To verify the reliability and repeatability of the
test method, 216 tensile specimens were cast from three different
UHPC types with fiber-volume fractions of 1, 2, and 3% and tested
at six laboratories. The measured responses were characterized
for different phases of the tensile behavior and analyzed to understand the scatter in the test data. It was found that testing can be executed with a 60 to 70% success rate with carefully prepared
samples and some modifications to the proposed test method. The
test results show an increase in both the tensile strength and multicracking phase with an increase in fiber-volume fraction, but the crack straining phase depends primarily on the type of UHPC.
Using the test data, average and characteristic tensile responses
were established, which are intended, respectively, for analysis and
design purposes.