If the precast concrete structure(pile, girder, culverts…ect) are to be cured with steam, the casting bed shall be completely enclosed by a canvas supported on framework or by some other type of housing, tightly constructed so as to prevent the ready escape of steam and exclude the outside air.
After the concrete has been allowed to take its initial set, from two to three hours after pouring, steam may be applied over a period of at least 36 hours. During this period the steam may be applied intermittently, but must be applied for a total of at least 24 hours and must not be turned off at any one time for more than 8 hours. The temperature within the enclosure shall be between 52°C and 65°C during the time the steam is being applied and shall not be allowed to drop below 27°C while the steam is turned off. Precast concrete structure cured with steam shall not be removed from the forms for at least 48 hours after the concrete has been poured.
Note:
Precast concrete piles, cured with steam, shall not be driven for at least 72 hours after being cast subject to satisfactory strength of the test cubes
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