Details of pile breaking after casting
The dissection of concrete piles is considered as a vital part of the construction process. The selection of a proper pile breaking method can lead to financial and programme savings as well as approach and minimize probable health and safety issues in regard to this stage of the works.
It is always recommended that bored cast in place concrete piles should have been cast to a level over the certain cut-off with the intention that as soon as the trimming is completed, a strong concrete connection with the pile is formed.
While developing the concrete pile foundations, it is necessary to build up or crop the piles to the perfect level to facilitate the sequential construction of pile caps or capping beams.
Pile Construction Method
Concrete comes under two prime categories - Cast insitu (e.g. traditional augered piles, continuous flight augered piles, secant piled walls and diaphragm walls) and Precast driven piles.
Cast insitu piles are cast to the exact level. The piles should be pushed or cast up to a piling platform level much greater than the formation level for the pile caps or ground beams. Once excavation is completed, it allows piles to be cropped to formation level.
Technically, it is essential to cast piles greater than the final level as laitance (filths amassed to the top of the pile) and defectively compacted concrete can then be separated to make it well compacted as well as produce superior quality concrete over the full length of the pile.
Precast piles are induced to a ‘set’. The level of foots of the pile necessary to attain the design set is inconstant. The final levels of the tops of the induced piles will differ and will not inevitably remain at the exact level for the construction of pile caps or ground beams. So, the cropping of these piles to the exact level is very essential.
Pile Cropping Method
The pile cropping method is vital to separate all concrete to the defined level, whilst parting reinforcing bars protruding to the plotted length to facilitate sufficient lap and/or anchorage into sequential construction.
Precaution should be taken while extraction of concrete to the exact level so that there is no damage to the pile concrete underneath the cut off level since it can impact the load bearing strength of the pile. The method should eliminate all damaged or poorly compacted concrete and laitance. The subsequent surface should be properly level to facilitate settling of reinforcing bar in the pile caps and leave an exposed aggregate finish to develop a proper construction joint.