MyMason's Case Studies
Chimneys and Brickwork Case Studies
Chimney Repair, Articulated Boom
Custom Scaffold, Chimney Repair
Lower-Chimney's Removal, Wall Restructuring
Chimney Flue Replacement
Concrete Chimney Cap as per Building Code
Chimney - Sloped Side, Repair
Chimney - Wobbly Chimney
Brick Garage Pillar Repair
Window's Lintel Installation
Brick Sill Creates Wall Damage
Brick-to-Stone Window Sill Replacement
Brick Retaining Wall Rebuild
Concrete Case Studies
Broken Concrete Step
Basement Window, Concrete Cut
Basement Window, Concrete cut-out
Concrete Walkway, Landing
Concrete Stairs and Landing
Concrete Stairs and Landing
Stone Work Case Studies
Stone Wall Rebuild
Granite Resurfacing of Concrete Stairs
Stone Step Rebuild
Stone Stair Rebuild - in Winter
Stone replaces Brick Door Sill
Stone Retaining Wall Rebuild
Dry-Stack Retaining Wall Rebuild
Dry-Stack Stone Retaining Wall
Flagstone Patio Rebuild, Expansion
FlagStone Step Repair
New Interlocking Stone Walkway
Re-setting Interlocking Walkway
Algonquin College/MyMason Case Studies
Cold Weather Masonry Rules
Salt and Concrete Testing
Concrete Curing Stress Tests
Concrete and Rebar Stress Tests
Parging Case Studies
Parging, Cement Board
Parging Examples & Techniques
Fireplace Case Studies
Fireplace Surround - Old Wood to New Wood Insert
Fireplace Fire Brick Replacement
Fireplace Surround - Natural Stone
Electric, Natural Stone Fireplace
Fireplace Hearth Replacement
Cultured Stone Fireplace & New Framing
Cultured Stone Fireplace Surround
TV Mounted on Stone Fireplace
Restructuring Fireplace: Wood to Gas
Drywall to Stone Fireplace
3-sided fireplace: Cultured Stone
Fireplace Removal, Damper Removal
De-Icers, Salt, Concrete and Cement Testing
Before and After
Working with Algonquin College
measure the effect of various salts
on different cements and concretes
The Testing Tools
These machines will test the compression strength of the cements.
The Masonry Lab is located within the Algonquin College School of Construction Excellence.
Three samples of each strength of cement will be created for each type of salt.
The cylinders hold concrete mixed to 32 and 20 MPA strengths (foundation and sidewalk strengths)
The cubes hold N type and S type, both used with brickwork, with S type twice as strong as N.
The water bath helps in the curing process. After the bath they are left indoors for more than 30 days.
Soaking in De-Icers|
A control set of cements will not be subject to salts, but will be wetted and kept outdoors.
Each bin contains a different de-icer, using: Potassium, Magnesium, Sodium and Calcium Chlorides.
A mixture of 2.5 quarts of de-icer with 11 quarts of water fill each bin, but can't prevent some freezing.
Rinsed with Water, Freezing
At frequent intervals the cements are removed from their solutions and rinsed.
They are then left wet to freeze outside of the solution. Always shielded from the wind.
The N type cement, weakest of our samples, is already cracking within the second week.
After only one exposure to the 4 different de-icers, cracks are forming in the N type cement.
Handling the Samples
The team is adding salt, fresh water, and moving the samples back into the solution.
L - R: Philip, Thomas, David, with Eric in foreground.
The materials are all kept in a locked dumpster on the grounds of Algonquin College.
The day started with windchill of -39, so it's warming up.
L - R: Philip, David, Eric, and MyMason's John Ernst
Early Concrete Degradation
The concrete in cylinder form, much stronger than the N and S cement cubes, is also flaking and cracking.
The 20 MPa concrete can handle about 3000 pounds per square inch, while the 32 MPa concrete handles almost 5000 psi using less water in the mix.
20 MPa is cited as normal for pathways, footings, driveways... What strength would you want?
A Warm Day
With temperatures above 10 degrees in late January, the solutions have no slush.
You can see evidence of the cubes breaking apart. Lifting them out, the N types do fail.
This is after just two weeks of rotation between salt baths and rinsing.
The S Type Begins to Fail
These cubes have been subjected to Rock Salt, which is least able to melt ice of the four de-icers we're using.
The Freeze Cycle
Here we lay the samples on top of their respective de-icer bins, pouring water on them to freeze them.
Usually two days later we will come to insert these frozen pieces into the de-icing solutions.
The N Type Fails
There won't be N type cubes to crush later on, except for our control pieces which haven't been subjected to de-icers, just freesing water.
The Tests Continued
The team of students and their Professors, with MyMason's John Ernst, continued the tests for nearly three weeks, due to the imminent failure of the samples. We had planned to test for three months.
Then all the samples were brought inside and crushed by the compression machines to measure their strength.
The Final Report
This PDF document, prepared by the Algonquin College team, shows how de-icers do cause damage to cement and concrete.
The take-home lessons are:
reduce the number of freeze-thaw cycles your concrete endures,
reduce the amount of water soaking into the concrete,
avoid using any type of de-icer, as it recrystalizes inside.
Use sand to increase the lifespan of your concrete.
Table of Results, 32 MPA Concrete
From the Report here is a table showing the break points of concrete normally used in sidewalks and patios, after being subjected to four kinds of salt on and off for 3 weeks.
The bottom line result isn't so much the difference between de-icers but how not using salt or any de-icer is good for your concrete.
De-icers cause freeze-thaw events and those are hard on cement and concrete.
Just 3 weeks of freeze-thaw cycles were required to cause this concrete to fail under-strength.
This page last modified: April 2013