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BUILDING CONSULTANTS INC.
.
Brick Testing in CanadaBrick Testing in Canada
BUILDING CONSULTANTS INC.
.
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Test ProceduresTest Procedures
What are the Standards?What are the Standards?
What is Measured?What is Measured?
What Should be Measured?What Should be Measured?
How Should Results be Presented?How Should Results be Presented?
Recommendations for Modifying BrickRecommendations for Modifying Brick
Testing?Testing?
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What are the Standards?What are the Standards?
CSA Standards (A82 Series) were adopted from anASTM procedure developed decades ago when brickwere manufactured using a wet mud process and slow
firing. Today, most facilities have a finely ground, extruded
brick fired quickly.
Still, the basic pass/fail criteria is that brick do not failunder freeze-thaw conditions of the test developed over50 years ago for brick made using a manufacturingprocess no longer in use.
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Code Requirements - General
OBC 97 4.3.2 Plain and Reinforced Masonry(1) Buildings and their structural members made ofplain and reinforced masonry shall conform to
(a) CSA-S304, Masonry Design for Buildings
OBC 97 5.1.4.2 Resistance to Deterioration
(1) Except as provided in Sentence (2), materials that
comprise the building components and assemblies that
separate dissimilar environments shall be
(a) compatible with adjoining materials, and
(b) resistant to any mechanism of deterioration which would
be reasonably expected, given the nature function and
exposure of the materials.
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CSA Requirements
CSA S304.1 - 3.4.1 Materials used in construction shall conform tothe requirements of CSA Standard A371.
CSA A371 4.1.2 Clay or Shale Masonry UnitsClay or shale masonry units shall conform to one or more of thefollowing Standards:
CAN/CSA-A82.1 Burned Clay Brick
CAN/CSA-A82.1 Burned Clay Brick says: Originally published in 1935 as A36 Revised in 1944 as A82
Revised in 1954 to include facing brick Revised in 1977
Revised in 1987 to SI Units and added Weathering Index Map ofCanadaImportant changes to 1987 version under 5.1 for Durability
Technically identical to ASTM C216-1986
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Grade Requirements
CSA A82 - Table 1: Two Classes MW and SW depending on F/T cycle-
days/year and precipitation during F/T cycle days.
MW used if Weathering Index 1500 cycle-mm and< 15,000 cycle-mmSW used if Weathering Index > 15,000 cycle-mm
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Weathering Index
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Physical Requirements.for SW Brick
Do F/T test0.800.78SaturationCoefficient
(C/B) (0 h)
Do C/B test 20% 17%Boil Absorption
(BA) (5 h)
Do C/B test
N/A
Typically
>> 20 MPa
& if Failure
10%8%Cold Absorption
(CA) (24 h)
< 17 MPa> 20.7 MPaCompressive
Strength (24 h)
No IndividualAverage (5)Property/
Test Duration
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CSA Freeze-Thaw Test Requirements
Dont use.
& if Failure
< 0.5% mass lossNo breakage &CSA/ASTM
Freeze-Thaw
(
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Freeze-Thaw Test Procedure
CAN3-A82.2-M78 (reaffirmed in 1992)
Purchaser or his representative is to sample 10 whole brick fromeach lot of 250,000 (or part) production representing the full rangeof colours, size, and texture.Problem: Often the supplier provides results of test performed bytheir own agent as proof of compliance.
Five brick selected from separate brick for use in test usingfreeze-thaw chamber that can reduce air temperature to 9 deg Cwithin 1-h..Problem: Very few commercial freezers can perform to this levelunless surcharged with frozen materials. Andwhere is thetemperature measured?
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Freeze-Thaw Test Procedure (Contd)
One set of 5 cycles involves. Step 1- Bricks oven dried and weighed
Step 2- Initially soak/submerge for 4-h Step 3- Then freeze face-down in shallow tray in 10 mm water for
20 h Step 4- Remove from freezer and thaw submerged for 4 h Step 5- Steps 3) and 4) repeated 5 times = 5 days
Step 6- On 6th day air dry samples for 40 h Step 7- On 8th day inspect brick and weigh.
Repeat Steps 2) to 7) 10 times.
Problem 1: Ideally the test is started at 8:00 a.m on a Monday. This requireswork on Saturday until 12:00 noon. For 10 weeks.
Problem 2: The brick are allowed to dry for 40 hours every 5 cycle set. (Howdoes this relate to actual exposure conditions?
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Research Findings
1990 CBAC/IRC Industrial Fellowship reportfound:
(a)24h cold water absorption (CA) vs. saturationcoefficient (C/B) identifies a characteristicfingerprint for a particular brick (constituentmaterials and manufacturing process)
(b)Water content increases to the 10th cycle thendecreases with each drying cycle but increasesagain at end of every 5 cycles of freezing andthawing. Maximum water content achieved isapproximately that for 5 to 15 days submersion
and slightly above the 24h CA value.
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Fingerprinting Brick
(a) 24h cold water absorption (CA) vs.saturation coefficient (C/B) identifies acharacteristic fingerprint for a particularbrick (constituent materials and
manufacturing process)
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Sample Set B
Fingerprinting Brick
Sample Set A
0.50
0.55
0.60
0.65
0.70
0.75
0.80
0.85
0.90
5.0 6.0 7.0 8.0 9.0 10.0 11.0 12.0 13.0
% CA
C/BRatio
Sample Set C
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Fingerprinting Brick
0.50
0.55
0.60
0.65
0.70
0.75
0.80
0.85
0.90
5.0 6.0 7.0 8.0 9.0 10.0 11.0 12.0 13.0
CSA Pass
C/BRatio
CSA Fail
CSA Pass CSA Fail
% CA
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Freeze-Thaw Cycles
(b) Water content increases to the 10th cycle thendecreases with each drying cycle but increasesagain at end of every 5 cycles of freezing andthawing. Maximum water content achieved is
approximately that for 5 to 15 dayssubmersion and slightly above the 24h CAvalue.
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F-T Moisture Content CSA Test
%
Absorbed
Cycles
0
2
4
6
8
10
12
14
16
0 5 10 15 20 25 30 35 40 45 50
Cold Absorption = 10%
Boiling Absorption = 12%
C/B=0.83(fails CSA)
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%
Absorbed
Cycles
0
2
4
6
8
10
12
14
16
0 5 10 15 20 25 30 35 40 45 50
Cold Absorption = 10%
Boiling Absorption = 12%
C/B=0.83(fails CSA)
F-T Moisture Content No-Dry Test
%
Abs
.
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Weight Loss by F-T Test
0
1
2
8.0 8.5 9.0 9.5 10.0 10.5 11.0 11.5
% Cold Absorption
%LossinW
eight
50 Cycle No-Dry
100 Cycle CSA
50 Cycle CSA
0.5% MAXIMUM MASS LOSS
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Weight Loss by F-T Test
0
1
2
3
4
5
6
7
8
9
10
8.0 8.5 9.0 9.5 10.0 10.5 11.0 11.5
% Cold Absorption
%LossinW
eight
100 Cycle No-Dry
50 Cycle No-Dry
100 Cycle CSA
50 Cycle CSA0.5% MAXIMUM MASS LOSS
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Pore Size Distribution
0
10
20
30
40
50
60
70
80
90
100
0.0010.010.1110100
Equivalent Pore Diameter,
%
IntrudedVol
ume
2.8
More Durable
Brick (35% Pore
Volume from 1
to 0.1 um)
Non-Durable
Brick (Pore
Volume ~58%
from 1 to 0.1 um)
Desirable: Minimum of 18 %of Pore Volume > 2.8 um
ExposedPore
Mercuryunder
Pressure
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SummarySummary
CSA Standard Tests for Bricks were developeddecades ago and applied to processes largely out ofuse. Lessons can be learned from European testing of
brick which applies different methods more alignedwith exposure.
SW-Class brick based on +1500 cycle-mm should bereviewed and split to allow specifiers to call for:
More extreme building exposure conditions, e.g., parapets,
wing walls, high corners, etc. More extreme environments, e.g. south-central Ontario or
Eastern Canada.
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Summary (Contd)Summary (Contd)
Current F-T pass/fail criteria (0.5% mass loss) allows arather high (4-loonie to 1 mm) face spall rate andshould be reviewed.
A certification or other quality management processfor brick testing should be implemented to assurepurchasers that brick testing and equipment usedcomply with standards.
Testing agencies should consider providing graphical
output to better visualize the results and isolateanomalies.
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Summary (Contd)Summary (Contd)
The Fellowship report identified brick testprecision errors that should be incorporated intothe test method. These deal with:
24 h is insufficient time to dry some low absorptionbrick.
Cooling after the 5 h boiling test should bestandardized
Freezing chamber should not have thermalstratification and must cool sufficiently.Time/Temp records should be kept.
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Summary (Contd)Summary (Contd)
F-T Testing from Monday to Friday requiresSaturday morning work. Failure to meet preciselythe test cycle times can result in over-drying.
The orientation of the brick during drying (face-upor face-down) is not specified but will affectmoisture content at the exposed face.
The definition of F-T failure should be re-examined. Not only is a large area of spalling
allowed but micro-cracking and strength loss willhappen prior to actual spalling or weight loss.
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Summary (Contd)Summary (Contd)
The F-T test should be updated, perhaps to the No-
Dry procedure to better model Canadian wet-cold
conditions.
As an alternative to the CSA requirement that
Purchasers select brick for testing and to expedite brick
approval, brick manufacturers may consider a product
certification program employing parameters that relate
in-situ performance with material properties such aspore size, cold water absorption, and a modified
freeze-thaw test.
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GRG Building Consultants Inc.GRG Building Consultants Inc.
Need someone to
take a closer look?
Facility Audits and CapitalExpenditure Planning
Specifications and ProjectManagement
Investigations and Consulting
Litigation Support
Arbitration and Mediation
1(800) 838-8183, Fax 1 (905) 895-7568
A .pdf of this presentation is available @
www.grgbuilding.com