Ward R. Malisch Concrete Construction Symposium (Part 1)-Large-Scale Testing of Cold Curing Water (Recorded presentation)

Large-Scale Testing of Cold Curing Water (Recorded presentation)

Video Transcription

Video Summary

Ron Kazakowski presents findings on the effects of cold curing water on concrete thermal contraction. He critiques the conservative 20-degree temperature difference guideline for curing water, tracing its origins to outdated recommendations only related to immersion curing. Through mock-up and field studies, Kazakowski examines temperature stresses in concrete, embedding thermistors to measure differentials. Initial studies showed no cracking despite a 50-degree differential. A larger scale study on a concrete slab revealed similar findings even with a 70-degree temperature difference. The results suggest that the concrete’s elastic behavior at early ages can handle higher temperature differentials than previously thought. Kazakowski recommends updating the 20-degree limit to 35 degrees, aligning with standards for mass concrete. This adjustment acknowledges extensive field experiences and scientific evidence, arguing that the current guideline may not be reasonable for preventing thermal cracking, given the common practice and behavior of concrete under thermal stress.

Keywords

concrete thermal contraction

cold curing water

temperature differential

thermal cracking

concrete standards update