Runway repair work at Rarotonga International Airport has picked up again following multiple delays.

Work resumed on Friday following a five-month break, with the replacement of one of 60 slabs that have been identified as in need of repair. 

So far 18 slabs have been replaced.

Repair work on the runway began last December, however an increase in flights after quarantine free-travel to New Zealand for residents was established and periods of heavy rainfall have limited progress.

Over 3000 concrete slabs make up the runway.

Of those, 12-20 slabs located in the main traffic area of the runway have been deemed most in need of repair.

Contractors will be using fast-setting cement along with specialised equipment at certain stage of the project in an effort to work alongside flight schedules.

Each concrete slab is roughly 6x6 metres and 350 mm in depth while another 200 mm is allowed for packing as diggers clear each square.

Each square is cleared of the original sand base – laid nearly 50 years ago –  compacted and refilled with an aggregate base.

It takes about ten hours to prepare and pour each slab.

The project is estimated to cost around $6.5 million with a scheduled completion date of March 2022.