Page 5 - AM Retaining Wall -Magnumstone Extenders Technical Manual

MAGNUMSTONE EXTENDERS TECHNICAL MANUAL

MAGNUMSTONE EXTENDER VS NO FINES CONCRETE

A Simple Comparison

Based on the design shown on the opposite page, an estimation of costs based on quotes for materials and
installation in Sydney, New South Wales, has been provided to give a better understanding of the savings that can be
achieved when using the MagnumStone Extenders system instead of No Fines Concrete.

As the below identifies, the key savings achieved are captured primarily through substitution of no fines concrete,
an expensive material required in considerable volumes for this application, with MagnumStone extenders together
with aggregate and backfill materials which are considerably more affordable.

MagnumStone and No Fines Concrete MagnumStone and Extenders

Wall Height - 4 blocks 2.4 m Wall Height - 4 blocks 2.4 m

Length of Wall 50 m Length of Wall 50 m

m2 of wall 120 m 2 m2 of wall 120 m 2
no. of Blocks 162 units no. of Blocks 162 units

Depth of No Fines Concrete (from wall face) 1 m no. of Short Extenders (2nd Course) 81 units

Void per Block 0.18 m 3 Void per Block 0.18 m 3
Void behind Block wall 0.38 m 3 Additional void for drainage material 0.22 m 3

Depth of infill/backfill material 0.31 m 3

Volume of Aggregate 64.92 m 3
Volume of No Fines Concrete 91.25 m3 Volume of Backfill 37.02 m 3

Cost of Short Extender 79 each
Cost of Aggregate 64 $/m 3

Cost of No Fines Concrete 180 $/m 3 Cost of Backfill 45 $/m 3

Total Cost $16,424.75 Total Cost $12,220.24
Earth pressure vector
Gravity vector of wall
Reactive force vector
Saving = 25.60%

All figures noted above are based on a 1 metre high retaining installed in good soils and with supply of materials and
installation in Sydney, New South Wales. Pricing noted has been quoted by independant third parties.

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