Sika answers permeability with hydrophobic and hydrophilic admixtures

Sources: Sika Corp., Lyndhurst, N.J.; CP staff  

The introduction of a powdered, concrete plant-dispensed agent positions Sika as the only admixture producer to offer the two core permeability reducing technologies: hydrophilic crystalline and hydrophobic pore blocking. The hydrostatic application-geared WT-240 P is in the former category and meets ASTM C-494 Type S requirements. Its moisture activated compounds produce insoluble crystalline deposits that form within the capillary system. The crystalline formulations have the ability to reduce capillary pore size and prevent water penetration in concrete slabs or structures.

Use of WT-240 P in watertight concrete applications, Sika notes, can result in up to 85 percent permeability reduction, per DIN 1048 testing; uniform waterproofing throughout the entire concrete volume; improved hydrostatic pressure resistance; and, sealing of up to 0.016-in. cracks. A companion agent, WT-240 P Red contains a color tracer making it visibility apparent that a concrete contains the crystalline based permeability admixture.

WT-240 P can be used with Sika’s hydrophobic pore blocking admixture, Watertight Concrete Powder, to lower permeability in hydraulic structures whereby they retain water or keep it from infiltrating conditioned spaces. Integral admixtures provide expedited slab or structure completion and reduced labor costs when compared to traditional concrete waterproofing methods involving loose-laid or adhered membranes, Sika contends.