EVOLUTION OF FRACTURE-BEHAVIOR OF SATURATED CONCRETE IN THE LOW-TEMPERATURE RANGE

Notched beams of saturated concrete were tested, according to RILEM procedure, at temperatures ranging from 20 to -170°C. A model recently proposed by the authors, the Perturbed Ligament Model, was used to obtain size-independent GF values. Results show that the pertur- bation lengths are temperature independent, supporting the idea that size dependence of Gf as determined by RILEM method is generated by damage during manufacture of specimens rather than during testing. The results show a strong increase in fracture energy with decreasing temperature. The characteristic length lch also increases, and relative structural brittleness, lch (20)/1ch(T), experiences a four-fold decrease from room temperature to -170°C. © 1990.