Frequently Asked Questions

How does Proofex Integral achieve self-sealing of cracks that develop after the concrete has hardened?

The self-sealing mechanism of Proofex Integral depends on the presence of residual unreacted reactive chemicals distributed throughout the concrete matrix from the initial admixture addition. When Proofex Integral is added to fresh concrete at the batch plant, the reactive chemicals dissolve in the mix water and begin reacting with the calcium compounds in the cement paste to form the initial crystalline infill of the capillary pores during the first days and weeks of curing. However, not all the reactive chemicals are consumed in this initial reaction — a significant portion remains as latent reactive compounds dispersed within the hardened concrete matrix, adsorbed onto the surfaces of cement hydration products and aggregate particles throughout the full depth of the section. When a fine crack develops in the concrete section — whether from shrinkage, thermal movement, structural loading, or settlement — and water enters the crack and contacts the crack faces, the moisture reactivates the latent reactive chemicals in the concrete adjacent to the crack faces. These reactivated chemicals dissolve into the water in the crack and react to produce new crystalline growth that extends across and progressively fills the crack aperture. The self-sealing is most effective for cracks below approximately 0.3 to 0.4 mm width — wider cracks require mechanical repair with Fosroc injection or repair mortar products to restore structural continuity before the crystalline self-sealing can be relied upon for waterproofing.

Does using Proofex Integral as the sole waterproofing measure eliminate the need for any surface waterproof membrane in a basement construction?

For many below-ground concrete structures, Proofex Integral added to the concrete mix provides sufficient waterproofing to eliminate the need for a separate external waterproof membrane — this is the primary advantage of the integral approach. British Standard BS 8102 (Code of practice for protection of below-ground structures) classifies integral waterproofing using crystalline admixtures as a Type B system (integrally protected concrete) and recognises that Type B alone is suitable for Grade 1 and Grade 2 usage (Grade 1: minor seepage tolerable; Grade 2: no damp patches or water ingress, ventilation acceptable). For Grade 3 (habitable basement space requiring Grade 3 dry environment — no moisture transmission through any part of the structure) and Grade 4 (archives, data centres, electronic equipment), a combination of Type B integral waterproofing and a Type A external membrane or Type C internal drained cavity system is typically specified to provide the redundancy required for the most demanding waterproofing performance level. In Indian construction practice, the decision whether to use Proofex Integral alone or in combination with an external membrane (such as Proofex Engage or a cementitious slurry) depends on the water table level, the aggressiveness of the groundwater, the criticality of the structure, and the drainage conditions at the site. A structural waterproofing engineer should confirm the appropriate system for the specific project conditions.

Can Proofex Integral be added to ready mix concrete at the batch plant or must it be added on site?

Proofex Integral is most reliably added at the ready mix concrete batch plant, where it can be accurately weighed and incorporated with the dry materials or dissolved in the mix water before batching — this ensures thorough distribution of the crystalline admixture throughout the concrete matrix. Adding Proofex Integral at the batch plant is the recommended procedure for infrastructure projects where consistency of the crystalline admixture dosage across all concrete pours is critical for reliable waterproofing performance. The admixture is typically batched in the dry form, added to the mixer with the fine aggregate or mixed with a portion of the mix water, before the remaining mix water and cement are added. For site batching operations where ready mix is not used, Proofex Integral can be added to the site mixer as a dry powder with the cement and fine aggregate at the start of the mix cycle. Secondary addition of Proofex Integral to concrete that has already been batched (adding to the truck drum at site after batching at the plant) is less ideal because the dry powder added to a wet mix in a revolving drum may not distribute as uniformly as plant batching — but it is an acceptable approach for urgent situations where plant batching of the admixture was not arranged in advance, provided the truck drum mixes for a sufficient additional revolution count after the Proofex Integral addition.