Guidance for the Placement of Concrete on Cold Surfaces

January 25, 2021
11:00 AM - 12:00 PM

Online Webinar: Call in details provided after registration completed.

Guest Speaker:
Ronald L. Kozikowski, PE, North Starr Concrete Consulting

Cold weather concreting strategies must protect the concrete from freezing and promote strength gain. Yet, the selected cold weather concreting strategy should also minimize the energy costs.  Heating formwork and rebar prior to placement is an example of an inefficient practice that has continued through the years due to a lack of information/understanding of what happens when fresh concrete is placed on cold surfaces.  This webinar provides a look into resent research that helped update ACI guidance on cold surfaces and redefine the size of massive metallic embedments.   

Research results confirm that: 

  • Cold formwork and steel surfaces cause negligible decreases in the as-placed temperature of concrete. 
  • Heating rebar prior to placement is an unnecessary time-consuming and costly process. 
  • Using proper insulating practices, heat from the concrete mass within formwork can be used to warm cold surfaces. 
  • Physical measurements of heat transferred between warm concrete (55°F (13°C)) and cold rebar (at least 10°F (?12°C)—will not freeze mixing water in concrete.  This was confirmed for rebar sizes up to a No. 18 bar. 

 

Ronald Kozikowski is a Professional Engineer, specializing in troubleshooting concrete construction issues. With 20 years of concrete construction industry experience, Ron has been the Vice President of North Starr Concrete Consulting since 2012. Throughout his career, he has developed extensive knowledge and expertise in a broad range of concrete materials related subject matter. Ron is a member and voting member of several industry organizations and is a well-respected and trusted educator having taught and given technical presentations numerous conventions and conferences. He has authored more than 30 technical articles and is co-author on a book focused on topping slab design for the American Society of Concrete Contractors. Ron is licensed in both Illinois and New Hampshire and holds a BS in Civil Engineering and a MS in Materials/Structural Engineering from the University of New Hampshire.

 

 

Tickets

$25.00 ACI Webinar: Member Registration

$30.00 ACI Webinar: Non-Member Registration

$5.00 Student Registration