Effects of polymer and bentonite support fluids on concrete-sand interface shear strength

Support fluids are widely used for the construction of deep bored piles and diaphragm walls. Specifications for the use of these fluids vary, and a thorough understanding of their effect on pile shaft resistance has not yet been developed. This paper presents the results of a set of concrete–sand interface shear tests carried out using both polymer and bentonite support fluids, with water as a reference fluid. It was found that polymer fluids had little effect on the interface shear strength when compared with water. Furthermore, in contrast to the results of earlier studies, concrete curing time was found to have little effect on the results. However, when bentonite slurry was used, the interface shear strength was found to decrease approximately linearly with the square root of the filtration time, until the strength of the pure filter cake was reached. This was due to the development of a bentonite filter cake at the interface so that only aggregate protruding through the filter cake made contact with ...

[1]  George M. Filz,et al.  Formation and Properties of Bentonite Filter Cakes , 1998 .

[2]  M. O'Neill,et al.  THE PHYSICOCHEMICAL INTERACTION BETWEEN PHPA POLYMER SLURRY AND CEMENT MORTAR , 2000 .

[3]  S. Jefferis,et al.  Polymer support fluids: use and misuse of innovative fluids in geotechnical works , 2013 .

[4]  Carlos Lam,et al.  Effect of support fluids on pile performance - a field trial in east London , 2010 .

[6]  M L Lings,et al.  The lateral pressure of wet concrete in diaphragm wall panels cast under bentonite , 1994 .

[7]  M. Duarte,et al.  Foam as a soil conditioner in tunnelling: physical and mechanical properties of conditioned sands , 2007 .

[8]  V. M. Troughton.  THE DESIGN AND PERFORMANCE OF FOUNDATIONS FOR THE CANARY WHARF DEVELOPMENT IN LONDON DOCKLANDS , 1992 .

[9]  R. R. Shakir,et al.  An examination of the mechanical interaction of drilling slurries at the soil-concrete contact , 2010 .

[10]  Mark Randolph,et al.  SCIENCE AND EMPIRICISM IN PILE FOUNDATION DESIGN , 2003 .

[11]  Dan A. Brown.  EFFECT OF CONSTRUCTION ON AXIAL CAPACITY OF DRILLED FOUNDATIONS IN PIEDMONT SOILS , 2002 .

[12]  L C Reese,et al.  DRILLED SHAFTS: CONSTRUCTION PROCEDURES AND DESIGN METHODS , 1999 .

[13]  Michael McVay,et al.  Influence of Torque on Lateral Capacity of Drilled Shafts in Sands , 2006 .

[14]  Stephan A. Jefferis,et al.  Reply to the discussion by Fellenius on 'Critical assessment of pile modulus determination methods' , 2012 .

[15]  Charles Wang Wai Ng,et al.  Performance of Long Rectangular Barrettes in Granitic Saprolites , 2003 .

[16]  M W O'Neill,et al.  PERIMETER LOAD TRANSFER IN MODEL DRILLED SHAFTS FORMED UNDER SLURRY , 1994 .

[17]  S. Jefferis,et al.  Observations on viscosity reduction of PHPA polymer support fluids , 2010 .

[18]  M. Coop,et al.  On the behaviour of Thanet Sand: an example of an uncemented natural sand , 2009 .

[19]  Diethard König,et al.  Zum Kontaktverhalten zwischen suspensionsgestützten Ortbetonwänden und dem anstehenden Boden , 2007 .

[20]  LamCarlos,et al.  Reply to the discussion by Fellenius on “Critical assessment of pile modulus determination methods”11Appears in the Canadian Geotechnical Journal, 49(5): 614–621 [doi: 10.1139/t2012-027]. , 2012 .

[21]  Kevin L. Nash,et al.  Stability of Trenches Filled with Fluids , 1974 .