Why Does the Deep Curing of Sealant Slow Down?

The objective conditions of sealant application have a significant impact on the deep curing speed of the sealant. Factors such as the construction environment, temperature, and humidity can greatly affect the curing rate. For example, excessively low temperatures or high humidity can significantly delay deep curing. Additionally, the ventilation conditions at the construction site also influence deep curing; poor air circulation can further slow down the curing process. At the same time, the design of the joint also plays an important role in deep curing. When the width-to-depth ratio of the joint is inappropriate or the depth is too large, the deep curing speed will noticeably slow down.

In the majority of cases, slightly slower deep curing does not affect the practical use of the project, as long as there are no quality issues (such as bubbles or incomplete internal curing). According to national standards, the curing period for test specimens is 21 days, and the thickness of the sealant in the test specimens is comparable to that in actual projects. This means that the national standard recognizes a full curing time of 21 days. However, the "slow curing" we refer to typically falls far short of 21 days (usually exceeding 5-7 days is considered slow curing).

Furthermore, we believe that excessively fast curing of sealants is not beneficial for long-term use, as rapid curing can hinder the release of stress caused by temperature changes during the curing process, potentially leading to hidden risks. For example, the curing time of concrete is also strictly regulated; if it cures too quickly, stress concentration may occur, leading to cracking. Therefore, a moderate curing speed helps ensure the performance and durability of the sealant.