Abstract:The pavement model constructed in a small test pit and compacted by a vibratory roller was loaded by a one third scaled accelerated instrument, Model Mobile Load Simulator 3 (MMLS3). The strains of different positions in the structure were collected and analyzed to explore the effective size of small scaled structure model. At present, the asphalt pavement model with cement treated aggregates base was tested. The preliminary analysis of data showed that in the zone under loading affection, the transverse strain at the bottom of the asphalt layers was tension strain and much more than the longitudinal strain. The state of longitudinal strain varied from compression to tension with the loading’s approaching and returned to the compression state with the loading leaving. The lateral strain is always tension strain. Based on the strain distribution with the distance, the effective size of the model can be determined as 100~120 cm in longitudinal direction and 50~60 cm in transverse direction.