What is driving post-tensioning demand in the GCC?
The GCC’s post-tensioning sector is confident about growth on the back of increased infrastructure and real estate development
Late in October 2015, Saudi Arabia’s minister of transport, Abdullah al-Muqbil, confirmed that the Kingdom’s public transport projects are not likely to be delayed despite the dip in global oil prices. Muqbil’s pronouncement of the significance of transport projects – which Saudi views as being critical to job creation and economic diversification away from energy dependence – ring a bell of hope for not only the country’s, but also the GCC’s post-tensioning sector.
Post-tensioning involves the strengthening of concrete by playing on its compression capacities, increasing its resistance to tension in the process. The technique is a significantly pertinent one while constructing roads and bridges, more so in a region known for its ambitiously-designed structures, such as the GCC.
According to a report titled What is post-tensioning by the US-based Post-Tensioning Institute (PTI), “post-tensioning allows bridges to be built to very demanding geometry requirements, including complex curves, variable super-elevation, and significant grade changes. Post-tensioning also allows extremely long span bridges to be constructed without the use of temporary intermediate supports. This minimises the impact on the environment and avoids disruption to water or road traffic below.”
John Habib, general manager for CCL Qatar, explains his firm’s experience of post-tensioning for bridges.
“CCL has been operating in Qatar for almost 12 years,” Habib says.
“The company has been commissioned to provide post tensioning services on several bridges. In addition, CCL carries support for precast industry units in terms of supply of pre-stressed accessories, equipment calibration, and design for precast post tensioned beams.
“CCL also supplies specialised spherical bearings and expansion joints for bridges,” he tells Construction Week.
Headquartered in the UK since 1935, CCL is actively involved in key construction markets in the Middle East region. In Qatar, the company has worked on varied projects, such as St Regis Hotel and Residential Towers, and the Qatar Primary Routes – North Road project. On the latter, CCL Qatar was commissioned to carry out post-tensioning works for three bridges on the Primary North Road.
The company installed multiple box girders with a span of 36m on the pedestrian bridges and a 35m span on the main bridge, which measured 90m in length.
Highlighting the benefits of post-tensioning to buildings, PTI’s report adds: “In building construction, post-tensioning allows longer clear spans, thinner slabs, fewer beams, and more slender and dramatic elements. Thinner slabs mean less concrete is required.
“Another advantage of post-tensioning is that beams and slabs can be continuous; a single beam can run continuously from one end of the building to the other. Structurally, this is much more efficient than having a beam that just goes from one column to the next.”
Dubai Civil Engineering (DCE), a part of the UAE-based Al Hamad Group, has worked predominantly in the building post-tensioning sector, and Ala’a Fawzat Sahawneh, specialist construction division manager at the firm, offers his insights on post-tensioning for high-rises.
Sahawneh says: “Most high-rise buildings use post-tensioning due to the advantages it provides over the traditional system, and the current level of demand for post-tensioned products and services is linked closely with high-rises.
“This is because the market of high-rise buildings has started to increase, and that demand is driving the use of more post-tensioning products.
“I feel the current demand for post-tensioning in the GCC can be rated as being between moderate and high.”
DCE has post-tensioned for high-rises in Bahrain and the UAE. This includes Villamar, a residential project comprising three towers at Bahrain Financial Harbour.
DCE’s scope of work at Villamar included the design, supply, and installation of the post-tensioning system for all project slabs, as well as the transfer beams supporting the villas located between the three towers.
The company has also installed post-tensioning systems in the UAE for the 23 Marina building in Dubai, and Ramada Hotel at Sharjah’s Buhaira Corniche.
“I expect the GCC’s post-tensioning sector to continue growing and developing, since it is one of the most used systems in this region for the construction of high-rise buildings, as well as horizontal structural elements, such as floors, beams, and transfer elements,” Sahawneh says.
DCE’s expert adds he expects this upward trajectory to sustain itself in the near future.
According to Habib, CCL also carries out engineering design for residential and industrial buildings, hotels, and office towers. The company was commissioned to design, manufacture, and install 49,000m2 of post-tensioned slabs at the Al Dana Tower development in Doha’s West Bay area.
As a result of the longer spans and thinner slabs, CCL was able to propose the addition of two extra floors to the project.
Commenting on working in Qatar, Habib says: “The government is heavily investing in the development of projects. Steady work is ongoing at the Doha Metro site, and the Orbital Highway project is also on track.”
Ask Habib if construction delays in Qatar are impacting firms such as his, and he is quick to point out the pace of work in the country.
“Delays are always found in construction projects, but there are controllable delays in Qatar. Typically, once the projects’ construction permits (DC 1 and DC 2) are issued, work on the structural elements will progress as scheduled.
“While there are no specific challenges to post-tensioning in terms of weather [in Qatar], general construction challenges include coping with over-demand of products when project work is accelerated, and changes in the design or purpose of a project under construction,” Habib concludes.