Company
home / Company
INTRODUCTION
- In the modern-day market, there is an ever-increasing demand from developers to design and construct using the most economical and environmentally sustainable building technology; the requirement for the most efficient structural form continues to grow. Driven by tighter programs and budgets, the expressions ‘value engineering’, ‘sustainable construction’ and ‘faster’, ‘lighter’, ‘stronger, are being used by Clients, Architects, and Design Consultants the world over. As a result, more and more developers are looking at the advantages offered by post tensioned solutions.
ABOUT AFORCE
- AFORCE has provided services to Project Managers, Architects, Engineers and Main Contractors globally earning an excellent reputation within the construction industry. The key to our success and growth is our ability to provide our clients with a full range of post tension services from the preliminary design phase to a project’s completion. We are often called upon at early stages of a project to consult on the design of special structures, bridges and buildings, where the project complexity could benefit with the introduction of post tensioning or other value engineering solution offered by Aforce’s Systems. Our advantage is the fact we also have extensive experience in similar projects both locally and internationally, complete with access to the latest design tools to provide our clients with the most practical and economical design solutions. Our in-house design and construction services provide our clients with a clear and direct line of communication that is essential for any team when executing a project.
ABOUT BONDED POST TENSIONED CONCRETE
- Bonded post-tensioned concrete is the descriptive term for a method of applying compression after pouring concrete and the curing process (in situ). The concrete is cast around a plastic, steel or aluminum curved duct, to follow the area where otherwise tension would occur in the concrete element. A set of tendons are fished through the housed duct and the concrete is poured. Once the concrete has hardened, the tendons are tensioned by hydraulic jacks that react (push) against the concrete member itself. When the tendons have stretched sufficiently, according to the design specifications, they are wedged in position and maintain tension after the jacks are removed, transferring pressure to the concrete. The duct is then grouted to protect the tendons from corrosion. This method is commonly used to create monolithic slabs for and can provide significant benefits to slabs on grade being constructed in locations where expansive soils create problems for the typical perimeter foundation. All stresses from seasonal expansion and contraction of the underlying soil are taken into the entire tensioned slab, which supports the building without significant flexure. The same methodology is practically applied to post tension slabs in a suspended slab structure which experiences similar benefits where upon completion of tensioning as detailed above the loads are predominantly distributed to the columns and the maximum support of the post tension tendon is provided mid span. Among the advantages of this system over un-bonded posttensioning are:
- Reduction in traditional reinforcement requirements as tendons cannot have gradual or immediate loss of force due to wedge failures.
- Tendons can be easily "woven" allowing a more efficient design approach.
- Higher ultimate strength due to bond generated between the strand and concrete.
- No long-term issues with maintaining the integrity of the anchor/dead end due to a fully bonded tendon.