Pile steam curing stage Instructions

PHC pipe production process, the primary steam curing is a very important part of the production process, GB "pre-tensioned prestressed concrete pipe pile" clearly states: put-tensioning tendons, the prestressed concrete pipe concrete compressive strength not less than 40MPa.In actual production, the compressive strength of the concrete pile ejection control 45MPa ~ 65MPa. Primary steam curing effect is good or bad,  not only directly affect  the pile of concrete stripping strength, but will affect the ultimate strength of the concrete piles. Here are pipe steam curing stage notes:
1. steaming pond before use to check valve leaks, the bottom is flat, if the condensate pump pumping clean and use.
2. pipe mold into the pool when the non-collision, and try to make the next big, small, tail pipe mold directly into the hole to avoid high velocity steam jet nozzles to avoid being washed out concrete wall.
3. the steam curing process generally divided static stops, heating, and cooling thermostat four stages, in strict accordance with technical specifications developed by the Ministry implementation need to be adjusted by the trial c

hamber issued a written notice.
4. autoclave heating speed is not too fast, usually about 35 ℃ / h, constant temperature stage to minimize the fluctuation range, check once every 15min temperature, adjust the feed rate.
5. the pool cover with water seal, the pool bottom temperature should be the same. Sealed tank may not have broken.
6. do the relevant records, heating stage temperature recorded once every 0.5h, 1h recorded once every stage thermostat temperature by the quality supervision and inspection, non-ahead to open the pool cover.
7. the thermometer should regularly check and found that excessive error must be promptly replaced.
8. the user can follow this steam curing regimes: Cancel static stops, 30min before heating stage heating 8 ~ 10 ℃, after every half an hour warming up 16 ~ 22 ℃, heated to 90 ~ 95 ℃, heating a total of 1.5 hours, thermostats 2 hours 45 minutes, the steam curing time 4 hours 45 minutes. (Time more conservative, not open pool advance)
Steam curing effect is good or bad, direct impact on the ultimate strength of the concrete piles. Therefore, the majority of users in the use of steam curing autoclave for pipe production according to standard operation, to ensure that pipe meet the national standards required.