Materials you will need: burlap, cardstock, ruler, X-Acto knife, computer, inkjet printer. 1  Measure out your piece of burlap to 8.5 by 11. Use the X-Acto knife to cut it. 2  Repeat with the card stock. 3  Use the masking tape to affix the burlap to the card stock. 4  Make sure your printer settings are set to Heavy Duty.
Ideally, concrete should be poured when the air temperature is between 50 and 90 degrees Fahrenheit. Cold temperatures slow the concrete-setting process, and when temperatures dip below freezing, the delay allows the water in the mix to freeze before the concrete hardens.
Effect of temperature conditions on the strengthdevelopment of concrete. Concrete for the lower curve wascast at 4Â°C (40Â°F) and placed immediately in a curing roomat -4Â°C (25Â°F). Both concretes received 100% relative-humidity curing for first 28 days followed by 50% relative-humidity curing (Klieger 1958).oncrete should not be placed onany surface that would lower the temperature of the as-placed concrete below the minimum values shown on Line4 in Table 14-1. ENCLOSURES Heated enclosures are very effective for protectingconcrete in cold weather, but are probably the most expen-sive too (Fig. 14-17).