Fine concrete pump for shotcrete in Oman
used for stabilising slopes during the construction of roads in Oman
The compact P 715 TD is demonstrating its outstanding versatility during the construction of a section of road between Bidbid and Sur.
The expansion of the infrastructure in the Sultanate of Oman has been a top priority for more than four decades. However, road construction is extremely difficult due to the rough terrain. The inland desert Dschiddat al-Harasis covers most of the central part of the country. Towards the coast in the northeast, the desert is hemmed in by a barren mountain range with peaks reaching up to 3,000 metres in height and this is precisely where the construction of the 35 km long road between Bidbid and Sur will take place. It forms part of the important road between Muscat, the capital of the sovereign state, and the southeast section of the coast. Where economically feasible, tunnels will be constructed to overcome the mountain range. In other places, the slopes will be blasted away and then stabilised to prevent landslides. The Omani Ministry for Transport commissioned the Turkish construction company
Slopes as high as 20 metres and outdoor temperatures of 40 °C provide a stern challenge.
Özkar Construction L.L.C. based in Muscat to construct the road. Following many positive experiences with the P 715 TD from Putzmeister, the Company decided to purchase another fine concrete pump of the same model to stabilise the slopes using shotcrete.
Careful preparations for a challenging task
On rugged sites like the one in Oman, the lightweight, hard-wearing plastic hood repels dust and stone impacts with ease. A stable shutter protects instruments and switches from damage.
Slopes as high as 20 metres and a rugged landscape provide a stern challenge for the robust piston pump from Putzmeister. The combination of outdoor temperatures of approx. 40 °C and 90 metres of hose between the pump and the shotcrete nozzle are equally as demanding. The concrete consistency had to be adapted precisely to the pump and ambient conditions to ensure that the material remains pumpable and does not harden. An engineer from Putzmeister was present on site to provide a supporting role. He conducted a series of delivery tests with and without fibre admixtures under real conditions to determine the right concrete formulas and make sure the concrete could be pumped over the long distances involved. It was also possible to adapt sections of the hose based on the results of the tests. Reductions at the end of the line usually caused the most problems. The transition from an inner diameter 65 mm to 50 mm, for example, poses a risk of blockages. The Putzmeister specialist also gave exact instructions on how to start pumping again following an interruption in operation using cement sludge with a
homogeneous, viscous consistence and a sponge ball.
Best prospects of success with the right equipment
The P 715 TD trailer-mounted fine concrete pump is extremely compact and lightweight, which makes it easy to transport and manoeuvre. These characteristics prove very advantageous on a construction site 35 km in length. The
powerful 2-cylinder piston pump also offers a host of advantages. It is driven hydraulically and generates a maximum pumping pressure of 68 bar, while Maximum delivery rate of 17.4 m3/h guarantees rapid construction progress.
Versatility is the main strength of this pump. Not is it only ideal for shotcreting, but also for pumping anhydrite, cement and cementrite self levelling floor screed, fine grained concrete with a grain size of 16 mm and pressure pointing
On rugged sites like the one in Oman, the lightweight, hard-wearing plastic hood repels dust and stone impacts with ease. A stable shutter protects instruments and switches from damage. The chassis and support feet are ideal for these conditions because they are robust and guarantee maximum stability at all times. The large hopper is also well equipped for this task. The low-wearing agitator can tackle heavy-duty mixes with ease, providing they are homogeneous. In addition to the Putzmeister fine concrete pump with matching hoses and a 50 mm shotcrete nozzle for a grain size of 8 mm, a compressor with air hose, a chemical tank with silicate metering pump for the binder and a truck mixer for delivering the fine grained concrete will be used to stabilise the slopes.