Concrete SlabQuality Requirements

Who Controls Concrete Quality• Polishing contractors have to perform

work on a concrete floor slab in which they had no control over design and placement quality

• Design professionals have to be proactive and see that certain requirements are included in concrete specification

Pre-Concreting Meeting

Polishing contractor should participate in the meeting

Flat Subgrade• Should be

uniformly graded flat and level

• Subgrade rises and depressions can cause variations in concrete slab thickness thus causing color differences because of differential curing and drying

Vapor Retarder• Product should comply with ASTM E 745

and have permeance of 0.01 perms after conditioning according to ASTM E 154 Section 7.1

• Installation should comply with ASTM E 1643

Concrete Mix Design• Consistent source for materials• W/C of 0.45• 3,500 psi• Normal weight aggregates• Not air-entrained• No replacements for portland

cement

Construction Joints and Patches• Strategically locate

construction joints to avoid mismatching segments

• Patch finish will not match surrounding surfaces

Steel Column BaseplatesBe aware of design of concrete at steel column baseplates

Placing• Comply with ACI standards• End of chute or tremie not

more than 6 ft above point of placement

• Monitor and control:- Concrete temperature- Water added at site

Flatness and LevelnessSpecified Overall

ValueMinimum Local

Value

FF Floor Flatness 50 35

FL Floor Levelness 30 20

Finishing• Specific procedures recommended• Steel trowel surface in three passes

without burning surface• Do not dust surface

with dry portland cement or sand to accelerate curing and drying

Curing and Drying• Evaporation control • Wet-curing method

EnvironmentalBenefits

Environmental Benefits• Polished concrete does

not have to be removed or replaced; it can be “forever”

• Light reflective• Durable• Flooring covering products not needed• Low maintenance requirements

WALTER SCARBOROUGHCSI CCS CCCA SCIP AIAwscarborough@hbig.us214.491.7385

D+D Specifiers Series

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