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Wagon Wheel-CS081120 Protection of Test Cylinders in Cold Weather Page 1 of 1 Carol Dye - Protection of Test Cylinders in Cold Weather From: Date: Subject: Attachments: "Donna Lange" <donna@gmeconsult.com> 11/2012008 10: 18 AM Protection of Test Cylinders in Cold Weather 2008 Cold Weather Cylinder Storage Memo.PDF Please see attached memo from GME Consulting Services regarding the Protection of Concrete and Masonry Test Specimens in Cold Weather. This memo is being sent to the superintendents on the jobsites where GME Consulting Services is performing concrete testing services. If you have any questions regarding this memo, please don't hesitate to call our office at 214.351.5633. <<2008 Cold Weather Cylinder Storage Memo.PDF>> Thank You, Donna Lange GME Consulting Services, Inc. Office Administrator 214-351-5633 file://C:\Documents and Settings\cdye\Local Settings\Temp\XPgrpwise\4925396BCity _ 0... 11/20/2008 DATE: November 20, 2008 SUBJECT: Protection of Test Cylinders in Cold Weather Winter is upon us and we may have several months with days and nights of cold and even sub-freezing weather. We at GME felt it appropriate to give everyone a reminder on some general concerns we have regarding the initial curing and field storage of your concrete test cylinders during this period of the year. Improper field curing of the test cylinders during cold weather can impact the initial and ultimate cylinder compressive strenhrths. We haven't experienced this as of yet on any of your sites, however, if care isn't exercised during the initial field curing of the test cylinders, then we should expect to see a reduction in the rate of strength gained from 0 to 7 and from 7 to 28 days. To reduce the potential for erratic strength results, we recommend that appropriate precautions be taken in the field to provide for the initial storage and curing of the test cylinders. It is important that some method be used which will allow for protection of heat loss from the cylinders during their initial 24 hours of curing. In this area of the country, we normally don't gct hard or prolonged Ireezing temperatures that require heated storage boxes. Normally, insulated plywood storage boxes with lids are adequate for the initial storage as the hydration heat of the concrete test cylinders tends to maintain the box temperature at a high enough temperature to reduce the potential for freezing or retardation of the curing process. Normally, a 4' x 8' box can hold 4 to 6 sets of cylinders. You can determine the number of boxes needed at the site by the average size oflarge pours (i.e. < 500 cy - 1 box) or the number of different locations at which you may be pouring concrete at the same time around the site. The box(es) will need to be pre-positioned near the concrete pours each time you have a pour in order to avoid unnecessary movement of the cylinders unless you are on a very small site.. The trades must be infonned not to remove these boxes or use them for scrap lumber. If we can implement this approach to protecting the cylinders during the initial curing process, we can likely avoid a lot of the unnecessary headaches, phone calls and delays, which otten result from low or questionable concrete strengths, which commonly occur during this period of the year. If you have any questions regarding this memo or our recommendations, please don't hesitate to call me at 2]4.35].s633,ow'~"~';". ~!~