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WARNING
This information applies to Lock-Block® products only. Other blocks do not meet the
strict dimensional tolerances and do not lock together into a cohesive wall
as effectively as Lock-Block® units. Using other blocks with Lock-Block® engineering data
could result in wall failures.
About
Lock-Block:
A Lock-Block™ gravity wall consists of the following components.
Mechanical properties and engineering significance of these components are
discussed below.
A.
Prefabricated
Modular Units - LOCK BLOCK®: Dry-stacked column
of concrete units that create the mass of gravity wall structure.
LOCK-BLOCK™ units are generally made of "return concrete."
Therefore, the compressive strength of these blocks can vary. Based on
several years of manufacturing experience in the Western USA and Canada, it
is known that the compressive strength of these blocks is generally over 20
Mpa (3,000 psi). The
compressive strength requirements of these blocks are governed by
durability requirements of a particular application. The compressive
strength and water absorption properties of the block can be modified for
projects situated at high altitudes in order to provide adequate
freeze-thaw resistance (durability) and resistance to the impact of
de-icing salts on highways. In such cases, generally, modifying the
material properties of blocks at the bottom of wall can adequately address
the freeze-thaw issue.
In addition to blocks made from return concrete, United Lock-Block can
produce special-order blocks with compressive strength of 40 MPa or more.
Because of good internal and external
drainage around LOCK-BLOCK™ units, concrete durability is enhanced. The
chamfered corners of the block provide approximately 5161 mm˛ (8 in˛) of
drainage area per block. Clearance of roughly 12 mm (1/2") around keys
provides additional drainage. Drainage backfill and discharge pipe placed
immediately behind the wall also provide drainage.
LOCK-BLOCK™ units are placed in a column so that they interlock at shear
key locations to provide structural integrity and wall batter. Wall batter
can be achieved by placing all blocks at an inclination. The center of
gravity of wall and wall batter are sensitive physical dimensions of the
wall structure with respect to the wall stability.
Weight of LOCK-BLOCK™ and shearing resistance developed at the top and
bottom surface of each block provide resistance to all destabilizing forces
generated by retained soil mass and surcharge loading.
In addition, LOCK-BLOCK™ units provide formwork for compacting soils behind
the wall, facial stability including erosion protection, and architectural
appearance to the retained soil mass.
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