One of the things I’ve always felt is a weakness of the concrete construction industry is how little research is done on the simple things that affect contractors. In the old days, Ward Malisch and Bruce Suprenant did some of that type of research for Concrete Construction and ASCC is funding some research today. But there just doesn’t seem to be the time or money for much of that these days.
So it’s to be celebrated when a concrete contractor like Dennis Purinton, owner of Purinton Builders in East Granby, Connecticut, did some basic cold weather concreting research last February. He placed 15 small slabs to determine the effect of cold subgrades and cold ambient temperatures on strength (you can read about it here http://www.forconstructionpros.com/article/11576734/cold-weather-slab-testing ). Purinton suffers from incurable curiosity—a condition that causes him to get very excited about things others might just accept as gospel. For example, in a recent conversation he wondered if critical saturation for concrete in cold weather is 91.7% as the books say, how would one know when concrete was at that percentage and how would one measure it in the field?
Purinton is proposing that we do a study to determine the usefulness of the current approach to cold-weather concrete work. For example, do contractors actually use ACI 306R-10, Guide to Cold Weather Concreting? Do they even have a copy? And if they do, do they understand how to use the tables and nomographs? I have a master’s degree in engineering and ACI 306 is not that easy for me to follow—pity the poor contractor! Would a more performance-based approach be better?
So, what we’re looking for right now isn’t so much the answers to the questions but the questions themselves. If we were to do a study to try to determine an alternative approach to protecting concrete in cold weather, what questions should we ask? What would you like to know?