A-Jacks Armour Units

A-Jacks are high stability concrete armour units used in both open channel and coastal applications. They can be manufactured in sizes from 35 kg to 20 tonnes. Open channel applications include bank stabilization, flow and grade control, scour protection for bridge piers, and biostabilization and generally use smaller A-Jacks. In coastal applications A-Jacks are used as breakwaters, revetments, offshore reefs, and habitat development.

A-Jacks have a high degree of interlock and porosity, leading to high stability coefficients in waves and currents.

A-Jacks are designed to optimize fabrication efficiency. The geometry allows for the use of very simple forms. Smaller sized units can be manufactured in conventional block machines which significantly reduces fabrication costs.

Unlike stone and older types of concrete armour units which are placed in two layers, A-Jacks are placed in a single layer. Combined with the high stability values and efficient fabrication, A-Jacks provide a very cost effective armour unit.

A-Jacks are used in both river and coastal applications. Structural loads are significantly higher in coastal applicatons and thicker A-Jacks which are more structurally robust are used. These slender and thick A-Jacks are termed River units and Coastal units.

This web site provides basic information on the use of A-Jacks in river and coastal applications. If you have any questions regarding specifying A-Jacks, past projects, design aids, or fabrication and construction methods, please do not hesitate to contact us.