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.