Pull-out behaviour of wood bolt fully grouted by PS-F slurry in rammed earth heritages

ABSTRACT

This article presents a laboratory and field investigation of pull-out resistance of wood bolts in rammed earth heritages. The laboratory testing involved axial tensile tests of four grout specimens prepared in specially designed moulds using PS-F (Potassium Silicate solution-Fly ash) slurry to investigate the performance of anchors. The field testing involved pull-out tests of three wood anchors installed in rammed earth heritages by gravity grouting. Experiments reveal that the failure mode is the pull-out of bolt from grout and average skin friction resistance of bolt–grout interface is approximately 0.34MPa. Load–displacement curves and elastic–residual displacement derived from cyclic loading indicate such anchor system has strong ductility with small elastic deformation and large residual deformation. Bond collapse firstly occurs at the loaded end and then propagates towards the full bonded length. Bond stress distribution is not uniform along the bonded length. Maximum bond stress distributes at the range from 0.3 m to 0.4 m. Emergence of compressive strain in the interface reveals such anchor system enjoys the advantages of both tensile and compressive anchor types, which significantly differs from results from other regular bolts. The research conclusion makes scientific senses to traditional material and craft in rammed earth heritages.

KEYWORDS:

• Wood bolt
• PS-F (Potassium Silicate solution-Fly ash) slurry
• rammed earth heritage
• pull-out resistance
• interfacial mechanical behaviour

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the National Natural Science Foundation of China 1 under grant number 51578272; Innovation group of basic research in Gansu Province 2 under grant number 2014GS03574 and National Twelfth-five Science and Technology Support Program 3 under grant number 2014BAK16B02.