What are the rules for placing concrete in cold weather on Massachusetts DOT projects?

"Cold conditions concreting shall be defined as the procedures, operations, materials, and equipment required for the mixing, delivery, placement, finishing, curing, and protection of concrete during cold conditions, while exposed to air temperatures fallin g below, or expected to fall below 40 °F . All procedures, operations, materials, and equipment required for adequate protection and curing shall be present and ready for use prior to concrete production." [1] "Cold conditions concreting procedures, operations, materials, and equipment shall be developed and performed to prevent damage to concrete due to freezing at early ages, to ensure that the concrete develops the recommended strength for safe removal of form s, to maintain curing conditions that promote quality strength and durability development, to limit rapid temperature fluctuation, and to provide protection consistent with intended serviceability of the structure. The Contractor shall develop and submit to the Department for review and approval, cold conditions concreting procedures for the mixing, delivery, placement, finishing, curing, and protection of concrete during cold weather, including:" [1] "• Procedures for protecting the subgrade from frost and the accumulation of ice or snow on reinforcement or forms prior to placement" [1] "Massachusetts Department of Transportation – Highway Division Standard Specifications for Highways and Bridges II.502 202 6 Edition Supplementary heat shall be supplied to enclosures by hydronic heaters, live steam, hot forced air, or indirect fired combustion heaters. Icing along the perimeter of the enclosure shall be prevented when live steam is utilized. Heaters and ducts shall be positioned to prevent the hot, dry air from overheating or drying the concrete surface. Insulating materials meeting M4.12.3: Sheet Materials shall be applied as a vapor barrier to the concrete surface immediate after final set is attained." [2] "901.33.B.3: Protection Period The protection period shall be defined as the minimum duration required to prevent concrete from the negative effects of cold weather exposure. The protection period shall remain in place while cold weather conditions exist. The procedures, operations, materials, and equipment selected for cold conditions concreting shall adequately maintain specified temperature ranges by addressing all variables, including ambient weather conditions, geometry of the structure, and mix design proportions. Concrete temperatures during cold conditions shall meet the requirements specified in Table 901.33 -1. Table 901.33- 1: Concrete Temperature Requirements during Cold Conditions Phase Cold Conditions Temperature (°F) Thickness of Sections (ft.) ≤ 1 > 1 ; ≤ 3 > 3 ; ≤ 6 > 6 Concrete Temperature (°F) Mixing 30 -39 60 -75 55 -70 50 -65 45 -60 0- 30 65 -80 60 -75 55 -70 50 -65 < 0 70 -85 65 -80 60 -75 55 -70 Placement < 40 55 -75 50 -70 45 -65 40 -60 Protection Period < 40 55 -75 50 -70 45 -65 40 -60" [2] "Termination of the protection period shall be conducted only after 100% of f’ c is attained and all specified conditions are met. Immediately after the protection period has concluded, the ambient temperature change period shall meet Table 901.33 -2. Table 901.33- 2: Ambient Temperature Change Period Thickness of Sections (ft) Rate of Ambient Temperature Change in 24 Hours (°F) ≤ 1 ≤ 50 > 1; ≤ 3 ≤ 40 > 3; ≤ 6 ≤ 30 > 6 ≤ 20" [2] "Cold Conditions; Ambient Temperature ≤ 40°F; Apply Department Approved Cold Conditions Plan; Protection Period" [3]

Every answer carries its source — tap a citation to read the official document.