Histogram testing for strength size effect in asphalt mixtures at low temperature

This paper presents a simple formulation to predict the size effect curve of mean structural strength of the asphalt mixture from the strength histogram obtained on single-size beam specimens under three-point bend tests. This method is based on the weakest link model (WLM), which relates the mean structural strength to the size dependence of the probability distribution of the material strength. The proposed formulation is verified by an extensive experimental work consisting of strength histogram and mean size effect tests on the asphalt mixture at low temperature. The mean strength size effect curve obtained from the WLM is found to be in very good agreement with the experimental mean strength results obtained on the asphalt mixture specimens of different sizes and geometries, providing evidence of the ductile to brittle transition (Type I size effect) of the asphalt mixture strength.