A new testing method to investigate the compacting behavior of fresh concretes under impact loading

Stéphane Pattofatto (1) , Arnaud Poitou (2) , H. Tsitisiris (1) , Han Zhao (1)

1 LMT - Laboratoire de Mécanique et Technologie
2 GeM - Institut de Recherche en Génie Civil et Mécanique

This paper presents a new instrumented Proctor test using a Hopkinson bar which allows for the original measurement of forces and velocities during the impact loading on soft fresh concrete samples. For this purpose, the specific points of using low impedance Nylon bar as well as the two-point measurement method to recover coupled waves are discussed. The whole test consists of successive impacts of low velocity (less than 3 m/s) exerted on the compressible specimen of a fresh concrete. The proposed original measurement allows for a quantitative comparison of the behaviour of the fresh concrete submitted to quasi-static and impact compaction. It shows that impact compaction is more efficient than quasi-static case. However, the increase of the impact velocity seems to reduce the efficiency. There exists probably an optimal loading path. The further understanding of the behaviour of fresh concrete under low velocity impact should be an interesting way to improve the industrial compacting process.

Mots clés: Proctor test; Compaction; Fresh concrete; Hopkinson bars

Domaines: Mécanique [physics.med-ph]; Matériaux

Stéphane Pattofatto, Arnaud Poitou, H. Tsitisiris, Han Zhao. A new testing method to investigate the compacting behavior of fresh concretes under impact loading. Experimental Mechanics, 2006, 46 (3), pp.377-386. ⟨10.1007/s11340-006-6419-3⟩. ⟨hal-01004916⟩