r - The Hong Kong Polytechnic University

The 5th Cross-strait Conference on Structural and Geotechnical Engineering (SGE-5)
Hong Kong, China, 13-15 July 2011
RATE DEPENDENCE OF ULTRA HIGH TOUGHNESS CEMENTITIOUS
COMPOSITE IN TENSION
S. L. Xu and H. D. Li
Institute of Advanced Engineering Structures and Materials,
Zhejiang University, Mainland, China.
ABSTRACT
This paper examines the effect of strain rates on the tensile properties of ultra high toughness cementitious
composite (UHTCC) under direct tension tests with the rates varying in the range of 4×10 -6 s -1 ~ 1×10 -1 s -1 . The
experimental results showed that UHTCC possesses significant strain hardening and excellent multiple cracking
properties under both static and seismic loading rates. It showed that the ultimate tensile strain lies in the range
of 3.7%~4.1% and is almost immune to the change of strain rates; the ultimate tensile strength and energy
absorption capability tends to continuously increase when the rate exceeds 1×10 -4 s -1 ; energy absorption
capability of UHTCC is about 1000~3000 times that of concrete under seismic loading rate; the average
ultimate crack widths were all well controlled below 0.1mm under all strain rates. These results revealed that
UHTCC is an ideal construction material for earthquake resistant applications. Several fitting formulas on the
relations between different mechanical properties and strain rates were given according to the experimental
results.
KEYWORDS
Ultra high toughness cementitious composite, strain rate, direct tension, strain hardening, multiple cracking.
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