Title:
Experimental Study on Dynamic Axial Tensile Mechanical Properties of Concrete and Its Components
Author(s):
Shengxing Wu, Yao Wang, Dejian Shen, and Jikai Zhou
Publication:
Materials Journal
Volume:
109
Issue:
5
Appears on pages(s):
517-528
Keywords:
component materials; cyclic load; dynamic axial tension; failure mechanism; initial static load; strain rate.
DOI:
10.14359/51684083
Date:
9/1/2012
Abstract:
A series of dynamic axial tensile tests were performed on concrete and its three components using a servo-hydraulic testing machine. The dynamic mechanical properties of approximately 200 specimens were tested under a dynamic load at strain rates that ranged from 10–6 to 10–2 s–1, different initial static loads, and cyclic variable-amplitude loads with different frequencies. The results indicated the following: 1) tensile strength is sensitive to strain rate in all these materials and the rate sensitivity of strength for concrete was close to the composite material with the lowest sensitivity factor k; 2) the elastic modulus is less sensitive to strain rate than strength in all the materials. The rate sensitivity of the modulus for concrete was close to its component material with the lowest sensitivity factor m. The interfacial transition zone (ITZ) had the highest m among the composites; 3) the stress-strain relation for mortar is almost completely linear before peak stress. In contrast, the stress-strain relations of the concrete, granite, and interface appear nonlinear when the stress is set at more than approximately 50% of the peak value, and the nonlinear section showed a linear trend with increasing strain rate; 4) an initial static load within certain limits increased the dynamic tensile strength. The critical initial static loads for the mortar, granite, interface, and concrete were 70%, 50%, 50%, and 30%, respectively; and 5) the cyclic loading history had the least influence on the mortar and the most influence on the interface. The influence of fatigue damage decreased when the loading frequency increased.