Suggested Grasscrete®
Specification
The
GRASSCRETE contractor is licensed and trained by Bomanite® Corporation, P.O. Box 599, Madera, CA 93639-0599.
The work is usually called out in a section of the specifications
separate from concrete and landscaping (Section 2-p Paving and Surfacing is
suggested).
SECTION
_____: GRASSCRETE
1.
Scope. All work
in this section shall be as designated GRASSCRETE in the plans. The work shall include all labor, materials,
equipment and transportation required to install GRASSCRETE.
2.
Contractor. The
Contractor for this work shall be licensed by Bomanite Corporation, P.O. Box
599, Madera, CA 93639-0599, (209)
673-2411. The licensee for this area is
BEYOND CONCRETE, 36 Industrial Dr., Keyport, N.J. 07735; Tel: (800) 972-0668;
Fax: (732) 441-3318; www.beyondconcrete.com; sales@beyondconcrete.com.
3.
Subgrade. The
subgrade for GRASSCRETE shall be prepared for expected loading and drainage
requirements. Subgrade for vehicle
traffic shall be in accordance with local concrete street specifications. (NOTE:
Because of the wide variety of soil types, weather and anticipated
loading, it is not possible to recommend one specific subgrade design. The specifier should keep in mind that
GRASSCRETE is porous, and much of the water which falls on the surface will
pass through to the subgrade. For most
applications except for very heavy loads, native soil having a minimum
"R" value of 30 and a compaction of 95% will provide a suitable
subgrade. In areas having poor soil
and/or very heavy anticipated loads, 4" or more of soil should be
excavated and replaced with compacted base rock.)
4. Concrete
Mix. The concrete shall have a
minimum compressive strength of 3,000 psi in 28 days (except in severe
freeze-thaw areas or for vehicles weighing 10 tons or more, in which case it
should be 4,000 psi). Portland Cement
shall conform to ASTM C 150, Type I, II, or V.
Aggregates shall conform to ASTM C 33 and be minus 3/8". Mixing water shall be fresh, clean and
potable. In freeze-thaw areas, air
entrainment of 6.5% to 8.5% shall be provided.
Water reducing admixtures and/or super-plasticizers are permitted and
shall conform to ASTM C 494.
5. Slab
Design. The
GRASSCRETE slab shall have a minimum thickness of 5 inches. Where used for emergency vehicle access
roads, all edges shall be solid concrete having a minimum width of 6 inches.
6.
Reinforcement. The
GRASSCRETE shall be continuously reinforced with _____ welded wire fabric
chaired between 2 and 3 inches above the subgrade. (Refer to the following section for guidelines on the selection of
reinforcement.)
Intended Use -- Welded Wire Mesh
a) Erosion control, parking lots, driveways,
access roads for vehicles weighing 10 tons or less -- 6" x 6"-10 ga.
x 10 ga. (6 x 6-W1.4 x W1.4)
b) Regular use by vehicles weighing more than
10 tons, and access roads for fire apparatus with outriggers -- 6" x
6"-6 ga. x 6 ga. (6 x 6-W2.9 x W2.9)
7.
Construction Process.
a) Subgrade
shall be leveled to a uniform plane 5-1/2 inches below the final grade of the
finished slab.
b) Welded
wire fabric shall be chaired.
c) GRASSCRETE
formers shall be placed on the subgrade.
d) Concrete
shall be placed and leveled to the tops of the GRASSCRETE formers. The concrete surface shall have a heavy rough
broom finish.
e) GRASSCRETE
formers shall be withdrawn after the concrete has hardened sufficiently.
f) Slab shall
be cured with suitable curing membrane.
(Do not use chemicals harmful to growth of grass.)
8.
Joints. Expansion
joints shall be provided wherever a GRASSCRETE slab abuts to other concrete or
structures. In traffic areas, steel dowels shall be used to transfer loads
between adjacent slabs.
9. Soil and
Seed. Holes
shall be filled with soil and grass seed or sod suitable for local conditions. (NOTE:
Typically done by landscape contractor rather than GRASSCRETE
Contractor.)
10.
Traffic. No traffic
of any kind shall be permitted on the GRASSCRETE slab until fourteen days after
placing of concrete, and only after soil is placed in holes. Thereafter, vehicles shall be permitted
providing they do not exceed the weight capacity for which the slab is
designed.
ADDITIONAL DATA:
1. Grass
Coverage. Surface
area is 47% concrete & 53% hole.
Grass usually covers much of the concrete in areas not subject to
regular vehicle traffic.
2.
Maintenance. GRASSCRETE
requires watering and mowing as would be normal for any lawn. Irrigation must be provided in dry climates
to keep the grass healthy. Mowing needs
are less in area of frequent traffic.
The grass roots are protected by concrete and are not damaged by vehicle
use.
3. Alternate
to planting grass. Holes may
be filled with crushed stone, seashells, etc., to provide drainage without
necessity to maintain grass.
4.
Drainage. GRASSCRETE
drains at about the same rate as would an ordinary lawn in the same
location. In other words, the presence
of the concrete has little effect on the drainage; the soil and the slope are
the controlling factors. A test report
by an independent laboratory on infiltration rates is available upon request.
Load Test Report.
A test report by an independent laboratory on a fire truck
load test is available upon request. A
33 ton Grumman fire apparatus with outriggers was tested with a horizontal
extension of 100 feet of its man-lift with 800 pounds of weight in the
man-lift. (Note that GRASSCRETE is a
continuously reinforced monolithic slab, and therefore has flexural strength,
unlike unit pavers.)
6. Alternate
Reinforcement. It is
acceptable to substitute steel reinforcing bar of equivalent reinforcement
value for the welded wire steel fabric; however, this will usually raise the
cost because of the additional labor required.
7. Concrete
Volume. GRASSCRETE
is 60% concrete by volume, and 40% void area, not including widened edges and
solid borders.
8. Slope
Paving. GRASSCRETE
can be readily installed on slopes as steep as 3:1. Steeper slopes are more difficult and costly, and 2:1 is the
steepest that could be possible.
9. Curved
Areas. GRASSCRETE
formers are square and are used most effectively in rectangular areas free of
obstruction. GRASSCRETE may be used in
curved areas and areas having obstructions, but there may be some design
limitations and increases in unit costs.
Copyright© Bomanite
Corporation 1995
®BOMANITE is registered trademark and servicemark with
the U.S. Patent Office and other countries.
®GRASSCRETE is a registered trademark with the U.S.
Patent Office. The trademark is owned
by Grass Concrete International, Ltd.
Bomanite Corporation is licensed in the United States by Grass Concrete
International, Ltd. to use its trademark.