The Waterproofing ChallengeDuring the design phase, technical discussions were held between SMR Projects and Morgan Sindall Underground Professional Services the JV designers. This was to explore how Xypex’s crystalline technology could assist in reducing the permeability of the concrete. This was especially important across the construction joints.Trials were undertaken in conjunction with a ready mix company to establish how the crystalline technology behaved within the very specific mix design. In addition, this was to prove its water tightness over standard tunnel construction methods. A number of trials were set up using with and without Xypex products for a clear comparison.