Title:
Effect of Strain Rate on the Compressive Strength Surface Cracking and Failure Mode of Mortar
Author(s):
Li Zhaoxia and Huang Yaoping
Publication:
Materials Journal
Volume:
95
Issue:
5
Appears on pages(s):
512-518
Keywords:
compressive strength; cracking process; failure mode; strain rate;
DOI:
10.14359/393
Date:
9/1/1998
Abstract:
This study aims to improve the knowledge on the strain rate sensitive behavior in compressive strength, cracking process and failure mode for brittle materials by testing concrete constituent, mortar, at different rates of straining. Cracks on the surface of specimen are observed with two Long Distance Microscopes (LDM) and recorded synchronously with loading and deformation response for the mortar at different rates of straining.. For the mortar in a range of strain rates from 0.2 to 20,000 microstrains/sec, the compressive strength increases with an increasing strain rate. As the strain rate increased, the failure shows comparatively more violence and faster time of crack propagation, with an increasing number of cracks and fragments. At a lower strain rate, cracking on the surface of specimens starts earlier and at a lower stress state than that at a higher strain rate. The strain rate effect on the failure mode and cracking process indicates the reason why compressive strength and other mechanical properties of mortar and concrete are sensitive to the strain rate.