00:01
Okay, for this question we're looking at what condition would linear elastic fracture mechanics be applicable to concrete? and what are the possible reasons and mechanisms for deviation of concrete fracture behaviour from predictions of lefm? so the conditions for this to be applicable would be small scale features.
00:24
So it's more applicable to concrete structures with small scale features such as thin sectors or elements with relatively small crack sizes compared to the structure.
00:33
Because this lefm assumes that the material behaves elastically up until the point of crack initiation.
00:41
So it's got low or no reinforcement.
00:50
It's commonly used for analysing plain or lightly reinforced concrete elements.
00:56
It's structures with significant reinforcement of the presence of steel can affect the crack behaviour, and other fractures.
01:02
Mechanics model may be more appropriate.
01:04
It needs low strain rates okay so lefm is suitable situations where low loading rates are low and the effect of dynamic or time dependent behavior is negligible okay so reasons now for mechanisms for deviation from lefm predictions so we have crack bridging so concrete is a heterogeneous generous material with aggregates and other components...