034_045ACACFoxStudios
10/21/04
7:24 PM
Page 37
Architectural Concrete
The Shaw and Sons Way
PHASE III CONCRETE PLACEMENT AND FINISHING
Without the proper execution of Phase I, II and III, architectural concrete
paving will be substandard. Shaw & Sons prides itself as a leader in
constructing high-quality architectural concrete paving. Some, but not all,
of the steps Shaw & Sons implements in this zone are as follows:
° Thorough understanding of the design intent by the Owner, Designer and
General Contractor before starting project.
° Joint creation of a concrete mix design for each paving type on the project.
° Verification of approved mix design for each truckload delivered to the job site.
• Adherence to “sole source” batch materials, i.e. sand, rock and cement,
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PHASE III
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throughout the duration of the project. Variations in batch material sources
will lead to unsightly “checkerboard” pours.
Strict adherence to quality concrete mix design principles by Shaw & Sons
which include, same-source batch plant materials, 6-7 sack cement content,
4” slump (+/- 1”), 2,500 min. PSI strength, a water cement (W/C) ratio
between .62 and .67, use of admixtures such as shrinkage reducers, integral
colors, and synthetic fibers.
When installing Lithocrete®, incorporate Lithocrete®’s three patented concrete
additives: Lithocrete® Conditioner, Lithocrete® Etch-Retarder and LithosealTM.
Placement, finishing and curing of concrete under strict adherence to ACI
standards, 2001 edition. Contraction and construction joints are precisely laid
out and saw cut straight and true to line and grade.
After Lithocrete® is installed, a final cleanup and a minimum of three coats of
clear, penetrating LithosealTM paving sealer is applied to the surface to reduce
surface staining and ASR (alkali-silica reaction).
PHASE II FORMWORK AND REINFORCEMENT
Without proper formwork and reinforcing, concrete will not achieve its full
architectural and structural properties which designers demand today. Some,
but not all, of the steps Shaw & Sons implements during construction of
Phase II – Formwork and Reinforcement are as follows:
• Layout, line and grades are checked and rechecked prior to beginning
construction.
PHASE II
• Layout is provided with digital equipment to an accuracy of ± 1/8
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th
of an inch.
Construction joints laid out to occur at predetermined locations placed
typically at 12-feet o.c.e.w. not to exceed 20-feet o.c.e.w.
Placement of polystyrene foam isolation joint material at vertical surfaces, i.e.
walls, columns, steps, utilities lids, etc.
Placement of steel rebar (not wire mesh) with proper clearances from
adjace nt formwork, subgrade, and paving finish surfaces. Rebar is typically
installed as #4’s at 18” o.c.e.w. Rebar minimizes slab cracking and
significantly reduces vertical displacement should a crack occur.
Adobe blocks are used to support rebar to the center of the slab.
Form lumber is new, Grade #2 S4S Douglas Fir or better.
Steel stakes are used in-lieu of wood.
Installation of ” Speed Dowel’sTM, spaced typically at 18” o.c. or match rebar
schedule.
PHASE I SUBGRADE PREPARATION
On every project, Shaw & Sons ensures that proper subgrade procedures
have been executed prior to beginning their work. Poor subgrade preparation
often leads to paving failure. Some, but not all, of the steps Shaw & Sons
implements during Phase I - Subgrade Preparation are as follows:
PHASE I
• Placement of a minimum of 2-inches of a washed concrete sand base over
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subgrade. Sand provides a “slip plane” for paving and allows for even
concrete hydration, which minimizes paving surface discoloration.
Verification of precise and complete subgrade elevations. Inaccurate or
incomplete elevations lead to paving “bird-baths” and awkward cross slopes
which may eventually lead to an unattractive paving product.
Verification that utilities, i.e. sleeves and pipes, have been placed below the
sand base and that the utilities have been backfilled to proper compaction
standards. Utilities encased in concrete paving lead to stress cracks on the
paving surface and should be avoided at all times.
Review of the Project Soils Report related to adequate compaction, base
materials and doweling/rebar requirements.
Placement of geotextile fabric or aggregate base, if required, in the Project
Soils Report.
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