Patience is a Virtue - Testing Confirms Liquid Hardeners Realize Maximum Performance When Applied After 28 Days
A growing trend within the concrete flooring industry is to apply liquid hardeners on freshly-troweled concrete in what is referred to as a “pre-seal” or a “cure-coat.” Conversely, Nox-Crete has historically advised applicators to wait and apply liquid floor hardeners a minimum of 28 days after concrete placement to allow for maximum performance. The 28 day recommendation was based on intuition and a strong understanding of the chemistry behind liquid floor hardeners and the means by which they densify concrete surfaces. The lack of conclusive data led Nox-Crete to not only ask but to answer the question, does the timing of the application (Day One vs. Day 28) impact the liquid floor hardener’s ability to improve abrasion resistance? Continue reading →
Though appropriate for its time, the Standard Test Method for Water Loss Through Liquid Membrane-Forming Curing Compounds for Concrete – or ASTM C309 – was developed when finishing techniques had not yet progressed to the effectiveness of contemporary practices. Wood float finishes, as required by ASTM C309 in accordance with ASTM C156, create a more porous surface than steel-bladed power trowel techniques commonly used today. Steel troweled finishes result in a harder, tighter surface that reduces moisture loss, aiding cement hydration.