Neoprene joints seals (existing and new) trial, diamond grinding impact on seals: Findings and lessons learnt M1 K2S Project

Presentation by Antonn Russek from ASCP Online Forum 18 August 2020

Findings and lessons learnt from existing neoprene joints, new joint seal trial, diamond grinding impact on seals from M1 Kariong to Somersby Project

Neoprene joint seal trial –findings

  • The most critical element in the process for Neoprene joint sealing is the accuracy of the saw cutting.
  • Regularity of the joint width, cut depth and edge profile is necessary
  • Two cut process for joint cutting must be utilised, as
  • The Neoprene seal musthave a bench to sit on in the joint –created by the 2ndsawcutat 35mm deep.
  • Effectiveness of silicone anchoring of the neoprene seals remains unknown from this trial.
  • Performance of the new neoprene seals during and following a diamond grind process remains unknown.
  • Neoprene is quick and easy (i.e. cheap!) to install in new concrete with a consistent joint profile
  • Neoprene is much more difficult to install in old pavements and will carry residual risk of early failure if joint edges and widths are inconsistent.
  • Based upon performance of the old neoprene joints still in service at K2S, once installed properly, new neoprene seals shouldbe a more robust joint sealing material than silicone and perform better for the whole life for a newly constructed pavement. Further investigation is warranted here.
  • Cast in-situ silicone sealants certainly have advantages for use in re-sealing applications, and installation in older or existing pavements with inconsistent joint profiles compared to neoprene

Neoprene joint seal trial – recommendations

  • Another trial, with focus on shortcomings from this experience.
  • Consider changing the R83 Specification and RMS Model Drawings to allow for use of neoprene joint seals in transverse joints, with restrictions on use in recently placed ‘new’ PCP only.
  • Consider increasing the depth of recess for joint seals from 5+/-3mm to 9+/-2mm to account for future diamond grinding on the network.

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