WRITTEN BY COLIN GIBSON

Licensed by two world renowned authorities in prestressing applications, Amsteele has a legacy of highly visible construction projects in southern Africa.

STRESS WITHOUT

SUFFERING

Quote

Amsteele’s core

business is the design,

supply and installation

of pre-stressing systems,

including both bonded and

un-bonded systems for building

and civil structures. The company

is active throughout Southern

Africa and has completed

projects in Namibia, Botswana,

Mozambique, Swaziland, Angola,

Tanzania, Zambia, Zimbabwe,

Kenya and Mauritius.

Amsteele was formed by

the merger of two former

leaders in the prestressing

sector in South Africa in 2000—

Amalgamated Prestressing and

Steeledale Systems—although

the company’s origins can be

traced back to 1969 in the

shape of CCL Stressing (South

Africa) the original forerunner to

Amalgamated Prestressing.

The company has built a

significant portfolio of completed

projects over the years, with

post-tensioned slab applications

including parking garages,

offices, residential complexes,

shopping centres, hotels,

hospitals, airport terminals and

sports stadiums. Civil projects

include bridges, reservoirs, silos

and general heavy structures.

Complementary to the pre-

stressing systems Amsteele also

offers products and services in

geotechnical, heavy lifting and

steel construction systems.

Post-tensioning is a method

of reinforcing concrete or other

materials with high-strength

steel strands or bars, typically

referred to as tendons. Post-

tensioning applications include

office and apartment buildings,

parking structures, slabs-

on-ground, bridges, sports

stadiums and water tanks.

AMSTEELE SYSTEMS

With operations in Johannesburg, Cape Town and Durban, Amsteele Systems has served the construction industry in Southern Africa and the Indian Ocean Islands with proven solutions to geotechnical, civil engineering and building projects.

Metals Centre’s unique claim to

fame: Being able to supply

various sections and extrusions of both ferrous

and non-ferrous metals in many different sizes and

formats, including cutting these to size, all under one roof.

Our main product items include:

Aluminum • Copper • Brass • Stainless Steel • Mild Steel •

Bronze • Fuel Rail Extrusion

Our laser and waterjet cutting service will make light work of

your precision cut components.

Everything “metal” that you may need we have, under one roof... ready to be cut-to-size and delivered to you.

011 493-4930www.metalscentre.com

18 John StUnit C1, John St WarehouseSelby ext. 11, 2001, Gauteng

In many cases, post-tensioning allows construction that would

otherwise be impossible due to either site constraints or architectural

requirements.

Steel reinforcing bars (rebar) are typically embedded in concrete

to limit cracking, but rebar is a “passive” reinforcement; it carries

no force until the concrete has already deflected enough to crack.

Post-tensioning tendons, on the other hand, are considered “active”

reinforcing. Because it is prestressed, the steel is effective as

reinforcement even though the concrete may not be cracked. Post-

tensioned structures can be designed to have minimal deflection and

cracking, even under full load.

Amsteele is licensed by two world renowned prestressing

companies, CCL Stressing Systems of Leeds in the United Kingdom

and DSI (Dywidag Systems International) of Munich, Germany. The

ability to offer the technology solutions of both of these licensing

authorities and component manufacturers gives Amsteel a distinct

advantage in the South African construction market.

To put this into context, CCL’s South African operations supplied

the prestressing solution to the Foreshore Freeway viaducts in Cape

Town in the mid-1970s – and the legacy of this operation now forms

part of Amsteele Systems.

CCL’s unbonded single strand tendon system is quick to install,

requires no grouting, and is able to cope with irregular slab shapes.

Single wire strands of 13mm or 15mm diameter are coated with

permanent corrosion inhibiting grease and encased in high density

polyethylene (HDPE) sheathing, continuously extruded over the

entire strand length to form a single strand tendon. Tendons are laid

in the slab according to specific profiles before pouring the concrete.

The grease reduces friction and allows (with the sheathing) for

free relative movement of the strand with respect to the surrounding

concrete during stressing. Both grease and sheathing provide long-

term corrosion protection to the steel. The strands are individually

attached at both ends to CCL unbonded mono strand anchorages

that are embedded in the concrete to transfer compression to the

slab after stressing.

CCL’s bonded systems incorporate groups of three, four, five or six

strands contained within a tendon in a flat duct anchored at each end

by CCL flat anchorages. The tendons are laid in the slab according to

specific profiles before pouring concrete. Ducts allow for free relative

movement of the strand with respect to the surrounding concrete

during stressing.

After stressing the strands individually with CCL hydraulic jacks

and attaching them to the anchorages, the ducts are filled with

cement-based grout that fully bonds the strands to the concrete

through the duct wall and all along the length of the tendon. The grout

creates an alkaline environment around the steel for permanent

corrosion protection.

DSI has been operating in Germany since 1927, and offers a

complete product line in strand post-tensioning as well as stay-cables.

The iconic Nelson Mandela

Bridge in Johannesburg features

DSI stay cables installed by

Amsteele Systems.

One of Amsteele’s recent

flagship projects is the central

terminal building at OR Tambo

International Airport in

Johannesburg. The multi-level

terminal building integrates

the international & domestic

terminals in line with the

airport flow, linking them to

a public transport centre and

the Gautrain Station, which

is directly connected to the

terminal. Departure activities

are primarily on the upper level

with Arrivals on the ground.

Another is the Cape Quarter

Extension in Cape Town, a

10-storey building with four

levels of underground parking,

three levels of retail shopping,

entertainment and restaurants,

and three levels of offices.

Amsteele offers a full range

of services from supply only or

equipment hire to full execution,

including planning, design and

specification of temporary

works and equipment, budgeting

and final quotations. It can

also manufacture and supply

temporary structures and

equipment where required. The

company has a network of in-

house and external engineers

and technicians throughout

southern Africa.

AMSTEELE SYSTEMS

0027 11 827 6721

WWW.AMSTEELE.COM

www.littlegatepublishing.com