Assessment of Pick-Excavability of Controlled Low-Strength Materials for Trenches

This paper reports research concerning the excavatability assessment of controlled low-strength materials for trenches with a pick, thanks to the proposal of a laboratory and a field test. Attention is specially focused on air-entrained mortars and very lean concretes. The scientific approach is first presented. Then details and results on the production and characterization of materials are given. Next, numerical studies in 3D and 2D, using Finite Element Method, are presented in order to study the behaviour of the backfilled materials under an action caused by a pick, and to investigate the new laboratory test. Moreover, we present the development of a new in situ mechanized excavation test. Some trenches were specially made to excavate materials manually and mechanically with the new in situ excavation test in order to propose excavatability thresholds.