A pressure-sensitive membrane solution being applied at the Jeddah office project.
BMC tackles complex tasks
BMC will use pressure-sensitive membranes for the first time in Saudi Arabia, in addition to introducing the PVC and Carlisle SynTec EPDM systems for some very complex projects.
01 November 2010
BMC, the waterproofing division of Kabbani Construction Group, continues to introduce innovative solutions and systems to the regional market, while being involved in some of the most complex waterproofing projects under way in the kingdom.
Its portfolio of ongoing sheet membrane solution projects will see the company using pressure-sensitive membranes for the first time in the country. Other new systems that are being used by the company include a complex PVC (polyvinyl chloride) compartment waterproofing system at the King Abdullah Road Cross Makkah Street Tunnel project in Al Khobar and Carlisle SynTec’s EPDM comprehensive waterproofing system including pile-heads special treatment for the Lamar Tower project in Jeddah.
BMC is currently using the pressure-sensitive membrane solution below slabs and basement walls at the Jeddah office building project for the Saudi Commission for Health Specialties. Hashem Contracting and Trading is the main contractor for the project and Mohamed Harasani Architects is the consultant and designer.
The pressure-sensitive membrane solutions are composite sheets comprising a robust HDPE (high-density polyethylene) backing, a pressure-sensitive adhesive and a trafficable weather-resistant coating. The pre-applied membranes are designed for use below slabs and on basement walls.
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Pile-heads at the Lamar Tower ... undergoing special treatment. |
“The membrane uniquely develops a continuous adhesive bond to concrete poured against it. This prevents water migration between the structure and the membrane, substantially reducing the risk of leaks,” says Waleed Abou-Shaker, BMC technical manager in the Western Region.
The advantages of the membranes are many, he says. “The membranes are versatile and can be used beneath foundation slabs and with single or double-sided formwork systems. They also seal adhesively to concrete,” Abou-Shaker points out. “They exhibit excellent chemical resistance, protecting the structure from salts and sulphate attack. Furthermore, a total system is available as support, including a full range of hydrophilic and PVC (polyvinyl chloride) waterstops for construction joint protection.”
The membranes are also lightweight and flexible, making them easy to handle and install without special corner pieces. There are no butt joints, as all joints have bonded ‘selvedge’ or taped overlaps for increased leak protection. In addition, their inert characteristic renders them unaffected by groundwater contaminants, ponded water or wet/dry cycling.
PVC compartment system
BMC applied a new PVC waterproofing design at the King Abdullah Road Cross Makkah Street Tunnel project in Al Khobar. The project, which involves waterproofing an area of 85,000 sq m for the municipality of Al Khobar, will take two years to complete. The main contractor on the project is Al Derbas Company.
The new waterproofing system uses the PVC compartment system for basement waterproofing works which, according to Tajamul Hussein, BMC division manager in the Eastern Province, “is a reliable technical solution for underground structure waterproofing that involves complex detailing”.
The system uses:
• A homogenous sheet waterproofing membrane, based on polyvinyl chloride (PVC-P) in a single or double layer form. The membrane – which is highly resistant to ageing and mechanical impact – can be installed on damp and wet substrate and is suitable for contact with soft water (aggressive to concrete). It has high tensile strength and elongation, dimensional stability, water vapour transmission ability, and flexibility in cold temperatures and is hot air weldable. It is also resistant to root penetration and micro-organisms and all natural aggressive mediums in ground water and soil.
• Flexible PVC waterbars for construction and expansion joints in concrete structures. They are available in different sizes and types, depending on the application. The highly durable products are suitable for high water pressure and easy to weld on site.
• Injectable hose with unique integral ‘valves’ for sealing and possibly resealing construction joints in watertight structures against water and salt water ingress. It uses special valve techniques for injection; and is re-injectable with acrylic resins and microfine cement suspensions. The easy-to-install hose is tested in water pressures up to 10 bar (100 m) and is suitable for many different structures and construction methods.
Carlisle systems
The company is poised to use Carlisle SynTec’s newly-introduced AFX TPO membrane for a Saudi Aramco project in the Eastern Province. This new membrane from the leading US-based single-ply roofing solutions supplier comes in a choice of white 120-, 135- and 155-mil membranes that are UL (Underwriters Laboratories) Class A rated; and a choice of hot-mopped or cold-applied adhesive. It has 75 per cent fewer seams than modified bitumen, has a wide window of weldability, and offers the ability to design a multiple ply redundant system, says Hussein.
Meanwhile, BMC has used the EPDM SureSeal system (0.06 inch thickness) also from Carlisle SynTec for an area of approximately 40,000 sq m in one of the most complicated structures – to waterproof the Lamar Tower project in Jeddah. The project encompasses more than 1,500 pile-heads that require special waterproofing treatment that is totally submersed under sea water. Al Joudah Contracting is the main contractor, Turner is the designer and Saudi Diyar is the consultant.
BMC, considered today as the largest applicator of waterproofing systems in the Middle East and North Africa (Mena) region, and reputed as one of the leading contractors involved in all types of membrane applications for the past two decades, is an approved contractor for major clients such as Saudi Aramco, Saudi Basic Industries Corporation (Sabic), and ministries of water and electricity, and environment.
“We at KCG are always seeking the latest technologies so as to provide the most cost-effective and efficient solutions to our clients,” comments Abdel Kader Malak, assistant general manager at KCG. “BMC, which has always valued its relationship with the suppliers, has established several strategic alliances with the biggest names in the industry and it will continue to serve the regional market by selecting the best waterproofing solution for each project,” concludes Malak.
