Problem Faced:

The Paint Discoloration Issue:

JUSCO encountered difficulties with paint discolouration and peeling on kerb stones, which were painted before the concrete could fully cure. The presence of curing compounds used to aid concrete curing contributed to the high alkalinity in uncured areas. This alkalinity caused a reaction with the paint pigments, leading to unsightly results.

Complication Detection Process:

Trial 1: Primer Application

Berger Paints India Limited's first attempt to resolve the issue involved applying a primer before painting. However, this did not provide the desired results, as the alkalinity of the uncured concrete continued to affect the paint pigments.

Trial 2: Organic Pigment-based Paint

In the second trial, Berger Paints India Limited tried using Golden Yellow Paint with an Organic Pigment. Unfortunately, this approach also failed to address the problem due to the persisting high alkalinity in the uncured concrete.

Root Cause Analysis:

 1. High Alkalinity: The uncured concrete's pH level was in the range of 12-14, indicating highly alkaline conditions. This alkalinity was mainly attributed to the presence of curing compounds applied to expedite the concrete curing process. These curing compounds often contain basic elements that raise the pH level of the concrete.

2. Lack of Full Cure: The rapid painting process, carried out shortly after the kerb stone installation, did not allow sufficient time for the concrete to complete its curing cycle. As a result, certain areas of the concrete remained uncured and retained high alkalinity due to unreacted curing compounds.

3. Chemical Reaction: The alkalinity in the uncured concrete, driven by the presence of unreacted curing compounds, caused a chemical reaction with the paint pigments. This reaction led to the dissolution of pigments, resulting in paint discoloration and peeling.

Solution Offered:

After extensive research and development, Berger Paints India Limited successfully resolved the issue. They applied a specialized primer designed for uncured surfaces, specifically considering the presence of curing compounds. This primer acted as a barrier, preventing the paint pigments from reacting with the high pH environment of the uncured concrete. Subsequently, they used Guideline RM 164 Paint, which adhered effectively to the prepared surface, providing satisfactory results with no discoloration or peeling observed.