CW Milestones Part-6 - Backfilling and top slab pouring

Once the proper curing of the foundation pad and columns has been achieved, backfilling of excavated area has to be started. At instances (as per project demand and mentioned in DEDs) the backfilling is also required for whole site up to a certain level. This is normally required, when EGL at site is lower than its surrounding. Or if there is risk of flooding during some part of year due to excessive rains etc.

In some rollout projects where BTS and Generator pads are under tower, the top slab or pad is supported by columns and is cast monolithically on beams connecting all the columns. And in some projects, there is separate pad for BTS/Equipment and Generator/Fuel Tank. In later case the, the supporting wall (either concrete or bricks) for pads, has to be raised before backfilling.

CW Milestones Part-5 – Concrete pouring of foundation pad and columns for tower (Greenfield Site)

Once the proper layout, excavation and lean concreting (CW Milestone Part -4) has been done, it comes now the time for steel fixing. The steel for pad/s and columns is then cut and bent according to bar bending schedule. In the meanwhile the size of foundation is marked over the lean layer. The steel for foundation is then fastened with the help of binding wires and placed over spacers to give specified cover in both horizontal and vertical directions. The main reinforcement for columns is also fastened which is extending from top right into the foundation re-bars. 

Workers tying steel ribs for foundation columns