2023 Advanced Concrete Polishing Techniques with Bob Harris

Learn from Bob Harris in this five part interview series with Jim Peterson, the founder of Concrete Network. You'll learn advanced techniques for both before and after polishing to ensure your 2023 projects come out great. Harris shares years worth of knowledge and troubleshooting tips for polishers. See an overview of each episode below and watch them all on YouTube!

Polished Concrete - Considerations Before the Pour

Episode 1 - Watch on YouTube

Bob Harris discusses with Jim Peterson some of the common issues contractors face when they polish concrete floors. Learn some general information about the importance of the substrate and how you can take precautions to make sure your project is successful.

• Importance of quality of mix design
• Evaluating substrate before you polish
• Checking elevations throughout the process
• Benefits of being a good color matcher
• Place and finish tips and tricks
• Taking precautions before beginning work
• Curing issues
• Build knowledge and ask questions

The Biggest Problems Encountered When a Polisher Shows Up On Site

Episode 2 - Watch on YouTube

Polishers often face various hurdles when walking onto a jobsite. Here, Bob Harris shares suggestions for professionally and efficiently overcoming some of these common scenarios—all while doing your best work as a polisher.

• Dealing with other trades
• Evaluating the slab
• Identifying problem areas
• Resolving delamination
• Walking the site before polishing
• Identifying curling

Polished Concrete Testing Devices and Why Test?

Episode 3 - Watch on YouTube

Before polishing a concrete surface, performing a thorough evaluation of the surface is crucial. Here, Bob Harris discusses several tests to perform to ensure the best polishing results.

• Mohs hardness test
• Chain drag test to determine delamination
• Chain drag test for large areas
• Close-up view of delamination
• Testing after scarifying, shaving, or grinding the surface
• Using an RA Meter
• Former meter for checking gloss
• DOI (Distinctness of Image) Meter to test gloss, DOI, and haze
• Calibrating and reading the DOI Meter
• Cart to hold DOI Meter and RA Meter

Color Correction of Polished Concrete

Episode 4 - Watch on YouTube

Weather, finishing conditions, and other factors can all lead to undesirable color variations on polished concrete floors. In this video, Bob Harris shows three examples of color variation and how the issues were resolved. He also offers suggestions for polishers to efficiently and knowledgeably blend colors to create the desired look.

• Why color variation happens
• Case Study: Resolving color variation from a pourback
• Making the surface porous
• Pre-coloring cold joints and lightest areas
• Color testing
• Mitigating purple hue in solvent-based dyes
• Re-densify to maintain color matching
• Case Study: Resolving color variation from curing blanket lines
• Case Study: Resolving color variation from bad cold joints and finishing practices
• Create samples and write formulas for reference

Polished Concrete Repair Considerations

Episode 5 - Watch on YouTube

It’s challenging to make a solid, good-looking structural repair. Here, Bob Harris discusses how to make repairs blend homogeneously with the existing concrete surface.

• Use the app ColorSnap to match colors
• Case Study: Repair on broadcast glass aggregate surface
• Create samples to make color matching easier
• Case Study: Exterior pedestrian bridge with cracking
• Considerations to make when routing cracks
• Repair samples: Which looks the best?
• Repairing at joint intersections
• Patching glass aggregate
• More repair samples
• Tips and tricks

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