Jeddah's giant port works

New machine four concrete pour, as foundation works are completed at Red Sea Gate

For its work enlarging the port in Jeddah, Saudi Arabia, the Al-Tawi Readymix Company did not use a truck-mounted concrete pump to convey concrete; instead, they use their new Telebelt TB 130 for 12 hours each day. The reason was that the installation of large quantities of concrete which, due to its composition, could only have been pumped with unjustifiably high wear costs. 

At the Jeddah Islamic Port, work is being carried out on a new container terminal which is situated close to the shore of the Red Sea. The contract for the US $230m “Red Sea Gate” project was awarded to the China Harbour Engineering Company (CHEC). The customer is the Saudi Trade and Export Development Company. Work began on the foundation excavations back in January 2008 and the planned construction period is 22 months.

Pier

Currently, CHEC’s main concern is the construction of the wharfage. The new pier consists of numerous large boxes made of concrete known as casions, which are poured into formworks on shore. After completion, a large gantry crane lifts the concrete elements onto a pontoon, from which they are placed into the water, at predetermined points.

Afterwards, the area of water between the artificial quay wall and the shore is filled in and fortified.

A total of 865 caissons are being built, in six different sizes. The dimensions vary between 9.5 x 9.5 x 4 m and 16 x 9.5 x1.8 m. On average, 180 m³ of concrete is needed for one underwater work chamber. When concreting first started, tests using regular concrete pumps from various manufacturers resulted in an extremely high level of wear on the machines. According to experts, the reason for this was that the smaller grain sizes were absent from some of the aggregates, and that the structural properties of the concrete could not be guaranteed.  



Concrete mix

The Al-Tawi Company brought their Putzmeister telescopic belt conveyor to the harbour as an alternative.

Like a truck-mounted concrete pump, it is mobile on the road and on a construction site.  The device transports the material to the placement site, first via a delivery conveyor and feed conveyor and then via a 4-stage telescopic conveyor belt.
 
Incidentally, this 45 cm wide main belt can be placed at an angle of up to 29° - this corresponds to a height of almost 21m.

The new machine conveys practically all bulk materials required for construction, such as top soil, sand, gravel, rubble and both pumpable and non-pumpable concrete. At the end of the conveyor belt, the material is transferred to a 4.5 m long flexible drop hose, from which it flows smoothly and evenly onto the placement site. As belt transport is particularly suitable for dry materials, it does not matter if the concrete consistency is only earth-moist, the water content value is particularly low, or the concrete grading curve is extremely unbalanced.

At the harbour construction site on the Red Sea, the Telebelt keeps having to be moved. This means that it achieves a concrete placing rate of ‘only’ 100 m³/h. On average, the 9 m³ and 11 m³ truck mixers are emptied after only five minutes and can drive back to the mixing plant. The concreting work is coordinated and supervised by Site Manager Hossam Abdel Aziz, a 27-year old civil engineer, who has worked for the Al-Tawi Group for a year and a half. 

Mixers

With mixing plants at seven locations, Al-Tawi Readymix is one of Saudi Arabia‘s main fresh concrete manufacturers.

The company uses more than 100 truck mixers throughout the country and also has a large fleet of truck-mounted concrete pumps, including 22 Putzmeister machines with a vertical reach of up to 63 m

Since last year’s Big 5, the company‘s fleet also includes a TB 130 truck-mounted belt conveyor made by the same company.

Interestingly, the seaport is one of the few where ships enter through a natural gap in the reef. The sea bed is reportedly littered with ships big and small that missed the gap and foundered on the coral.