Design requirements for post-pouring belt

The post-pouring zone construction drawings designed by the current design institute are not the same. The current specifications “Technical Specifications for High-rise Building Concrete Structures” (JGJ3-2002), “Technical Specifications for Underground Engineering Waterproofing Techniques” (GB50108-2001) and different versions of building structure construction drawings Concentrated, there are detailed regulations on the structural requirements of the post-cast belt. Since these specifications and standards are compiled by different expert groups, their content and requirements are different, each has its own bias, and there are inevitably some differences.

(1) The indwelling width of the post-cast belt is generally 700-1000mm, and there are three common ones: 800mm, 1000mm, and 1200mm.

(2) There are four types of seams for post-pouring belts: straight seams, step seams, notch seams and X-shaped seams.

(3) The steel bars in the post-pouring belt are completely disconnected and then lapped, and there are provisions for additional reinforcements if they are not disconnected.

(4) The supplementary pouring time of the post-pouring belt concrete is not less than 14 days, some are not less than 42 days, some are not less than 60 days, and some are 28 days after capping. High-rise building concrete structure technical regulations” (JGJ3-2002 stipulates that it is 14 days and 60 days.), the third edition of the manual of concrete structure construction, China Construction Industry Press stipulates that it is 28 days.

(5) For the concrete preparation and strength of the post-pouring zone, some require the original concrete to be upgraded to the first level of strength level, and some require the same level or level of non-shrinkage concrete to be poured.

(6) The maintenance time regulations are inconsistent, and there are several time requirements such as 7, 14 or 28 days.

The existence of the above-mentioned differences brings many inconveniences to the construction and has great scalability. Therefore, only by carefully understanding the differences in the specifications of each specialty and applying the specifications and regulations flexibly and reliably according to the characteristics and nature of the project can the project be effectively guaranteed. quality.