Fracture Energy and Strain Softening ofConcrete under Seawater Environment
ZHANG Peng,SUN Zhi wei,ZHAO Tie jun and WITTMANN F H
DOI:10.11835/j.issn.1674-4764.2010.01.014
Received September 03, 2009,Revised , Accepted , Available online July 01, 2015
Volume ,2010,Pages 72-77
- Abstract
Both Three Points Bending (TPB) test on notched beams and Wedge Splitting Test (WST) were carried out on concrete specimens under six different conditions, under which they were totally dry, partially dry, water immersed, seawater immersed, 5% and 23.4% NaCl solution immersed, respectively. The fracture energy of each type of concrete and their strain softening curves were calculated according to the force displacement diagrams and inverse analysis method. It was indicated that with water, seawater or salt solution penetrating into concrete, the surface tension of pore liquids in concrete increased, which resulted in the decrease of the surface energy and load bearing capacity of concrete. After water immersed, the maximum bearing loads of specimens’ were reduced by 19.6% (TPB) and 14.5% (WST) compared with those of totally dry concrete. And for those of seawater immersed, 28.9% and 21.7% were reduced respectively. Furthermore, fracture energy of concrete was decreased more than 24% and fracture toughness was reduced significantly as well for concrete with high concentration salt solution, which made crack formation in concrete easier. The adverse influence of seawater on concrete materials had been investigated in detail from the aspects of surface energy, fracture energy and strain softening.