Sika Sikadur-32 N

TRSC specifies Sikadur-32 N when the structural intent is a fully-bonded, monolithic-acting connection between new and existing concrete — particularly in section enlargement, new-to-old slab interfaces, and as the primer layer in CFRP plate bonding systems. The product's defining advantage is its moisture tolerance: it can be applied to substrates that are saturated surface dry (SSD), which makes it usable on freshly hydro-blasted concrete without an extended drying period. This matters in remediation because the time cost of waiting for substrates to reach 'dry' moisture state can dominate construction programmes on occupied buildings. The most common specification pitfalls TRSC encounters in the field are: (1) misjudging the pot life — Sikadur-32 N has a working time of approximately 40 minutes at 23°C and falls to under 20 minutes at 35°C, which is routinely the case on Queensland summer afternoons; (2) failing to mechanically prepare the substrate adequately — the product needs a sound, laitance-free, exposed-aggregate substrate, not just a clean one; (3) treating the application as a 'slop on with a brush' job — Sikadur-32 N must be worked into the substrate to fully wet the surface before the new concrete is placed, and the new concrete must be placed within the open time. We specify mechanical mixing for kits above 5 litres, hand-tool surface preparation by needle gun or hydro-blast (never wire brush only), and on-site moisture testing using calcium chloride or relative humidity probes where the substrate condition is not visually obvious. Site QA should include batch numbers, ambient temperature, and witness of substrate preparation before each pour.