Concrete shall be prepared according to the concrete construction mixture ratio provided by the site laboratory. Centralized preparation in mixing station is adopted, transported by concrete tanker or trolley, pumped by concrete pump truck or hoisted into the mould by crane to pour concrete. When the concrete mixture is transported to the pouring site, its slump should be checked. If it does not meet the requirements, it should be returned to the mixing station, and the test technician will decide whether to carry out the second mixing. If it still does not meet the requirements after the second stirring, it should not be used. When the concrete is transported by mixer truck, it should be mixed at a slow speed of 2 ~ 4r/min, and the concrete loading capacity is about 2/3 of the geometric capacity of the mixing drum.
Before concrete pouring, the sundries in the formwork and the soil on the surface of the poured concrete should be cleaned, and the supports, formwork, steel bars and embedded parts should be inspected and recorded, and the pouring can be carried out only after meeting the design requirements. Due to the high height of the capping beam, a special person must be appointed to direct the pouring.
When pouring concrete, it should be poured continuously. In order to ensure the workability and slump of concrete meet the specification requirements, concrete should be poured in layers, and each layer should be controlled at 250 ~ 300 mm When vibrating concrete, the internal vibrator should be used to vibrate in layers, and the spacing between vibrating points should be controlled at 150 ~ 250 mm, and the template should be carefully vibrated at150 ~ 250 mm.. When vibrating, the "fast insertion and slow pulling" shall prevail until the concrete surface no longer sinks, bubbles no longer overflow and the surface is completely submerged. When vibrating, special attention should be paid to stopping vibration and dense reinforcement. When considering the pouring scheme, attention should be paid to avoid concrete cracking that may be caused by uneven settlement and deformation of the bracket. After the completion of concrete pouring, the top surface of the capping beam should be leveled accurately according to the control elevation, and the top surface of the capping beam should be leveled and closed for the second time. The whole pouring should be covered and maintained quickly.
In the process of pouring (pouring), should assign personnel to check the template, bracket. Regularly check the stability of the template, and pay attention to whether there are phenomena such as mold running, mold expansion and slurry leakage. Find it in time and take timely measures to correct it, so as to plan ahead and nip in the bud.
When pouring (pouring) the capping beam, the rockfill concrete should generally be completed at the same time.