Tarbela Dam is one of the most iconic structures in Pakistan and its 4th extension was commissioned in 2013 in order to enhance water management and electricity production capacity by 1410 MW.

Project Requirements

A hydropower dam is a complex structure with a number of functions, from the main dam to spillways & intake structures and the powerhouse. The total volume of concrete for this project was 600,000 cubic meters. A key requirement of this project was the prevention of cold joints due to hot weather concrete work. There were also small concrete pours requiring more than 10,000 psi strength.

The project also required a speciality solution for shotcreting, which required that the water be reduced for high strength to offset the effects of using an accelerator, all the while ensuring that the rebound was less than 10%.

Proposed Solution

Vertex Chemicals worked hand in hand with the contractor across the 4 year duration of the project. Firstly, the stringent requirements set by the client had to be met, over the course of several trials, to ensure that the chosen company can not only meet the technical requirements but also be able to deliver large amounts of material, consistently, over the entire duration of the project. After several months of on-site testing, complimented by client visits to our lab and production facility, the client was convinced that Vertex was the right partner for the project and decided to make us the preferred supplier.

In order to ensure that no cold joints are created in the prevailing hot weather conditions, our team leveraged our in-house lab and worked closely with the client to develop a novel product just for this project, called Naphthaplast F-707L. The product successfully tested for zero slump loss, after 45 minutes, with initial slump of 180mm, testament to Vertex Chemical’s R&D capabilities and the ability to adapt to the client’s needs in less time. The product was tested in the highest site temperatures, which reached up to 45 degree celsius and the product continued to perform.