Dr Andrew Dunster, Principal Consultant BRE/file/10.pdf · Dr Andrew Dunster, Principal Consultant...
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Certification of Glass for Use in Concrete II
Dr Andrew Dunster, Principal Consultant BRE
ConGlassCrete – High Value Use of Waste Glass in Concrete Products
Overview of Presentation
• Product certification/pre-certification• Glass as a pozzolan
Test results and limits
• Concrete products containing glassTest results and limits
• Getting full approval
ConGlassCrete – High Value Use of Waste Glass in Concrete Products
BRE Certification
BRE Certification - who are they?• a wholly owned subsidiary of the Foundation
for the Built Environment (FBE)• a sister company to BRE• specialists in certifying products and services
to the building and construction industries
ConGlassCrete – High Value Use of Waste Glass in Concrete Products
Certification
• Certification is third party confirmation that products, services, systems and personnel meet and continue to meet certain standards and specifications
• The technical requirements are peer reviewed by an independent panel of experts
ConGlassCrete – High Value Use of Waste Glass in Concrete Products
Pre-certification
• Certification normally covers a material or product that is being produced (includes production control etc)
• Alternative: pre-certification testing report stating that a material should be produced to particular parameters (chemical composition, strength fineness etc)
ConGlassCrete – High Value Use of Waste Glass in Concrete Products
Objectives
The performance of the pozzolana/products and the limits on properties assessed by BRE using UKAS facilities:• Validate test data from CCC (pozzolana)
• Generate new test data (concrete products)
• Assess limits for certification.
• Check data for conformity with limits
ConGlassCrete – High Value Use of Waste Glass in Concrete Products
Glass as a pozzolana
Validation tests
ConGlassCrete – High Value Use of Waste Glass in Concrete Products
Sources of glass pozzolana
1- glass from bottle banks 2- glass bottles from pubs and clubs 3- glass cullet-reject from manufacturers 4- flat glass 5- end of life vehicle glass 6- fluorescent tubes
ConGlassCrete – High Value Use of Waste Glass in Concrete Products
Key properties of glass pozzolana (1)
Key properties (based on PrEN450):
•Total SiO2 (min %)
•Chloride (max %)
•Loss on ignition (max %)
•Fineness based on surface area (min)
•Strength Activity index (min, % control)
•Soundness (max expansion)
ConGlassCrete – High Value Use of Waste Glass in Concrete Products
Key properties of glass pozzolana (2)
Key properties (based on PrEN450):
•Particle density (min kg.m-3)
•Moisture content (max, %)
•Water requirement (max, % control)
•Initial setting time
•Lead and other metals levels (max)
ConGlassCrete – High Value Use of Waste Glass in Concrete Products
Six samples of glass pozzolana selected for validation testing
•Fluorescent tubes (post consumer unwashed)
•Container (green, rejected)
•Container (amber rejected)
•Container (post consumer unwashed)
•Plate (rejected)
•Windscreens (post consumer, unwashed)
ConGlassCrete – High Value Use of Waste Glass in Concrete Products
Results: Soundness and setting time
170180165190180190160Initial setting time (min)
1.01.00.00.500.01.0Soundness,
max expansion
(mm)
Windscreens (unw)
PlateCont (unw)
Amber cont
Green cont
f/tubes (unw)
Ground glass sourcePC Control
ConGlassCrete – High Value Use of Waste Glass in Concrete Products
Results: Strength activity index 28 days
0
20
40
60
80
100
120
PC Control fluor tubesunwashed
Green container Amber container Containerunwashed
Plate Windscreensunwashed
Stre
ngth
act
ivity
inde
x (%
)
UoS 28 days
UKAS 28 days
ConGlassCrete – High Value Use of Waste Glass in Concrete Products
Results: Strength activity index 90 days
0
20
40
60
80
100
120
PC Control fluor tubesunwashed
Green container Amber container Containerunwashed
Plate Windscreensunwashed
Stre
ngth
act
ivity
inde
x (%
)
UoS 90 days
UKAS 90 days
ConGlassCrete – High Value Use of Waste Glass in Concrete Products
Results: Specific surface area of ground glass pozzolana (Blaine
method)
050
100150200250300350400450500550600650700750800850900950
fluor tubesunwashed
Green container Amber container Container unwashed Plate Windscreensunwashed
Spec
ific
surf
ace
area
(M2 /k
g)
ConGlassCrete – High Value Use of Waste Glass in Concrete Products
Key limits for ground glass as a pozzolana
(30% cement replacement)
10 mm[2]BS EN196-3Soundness, maximum
expansion
(25% cement replacement) at 28 days
75% -5%at 90 days 85%-5%[1]
BS EN 196-1Strength Activity index, minimum. percentage of control
300 m2/kg minimum BS EN 196-6Fineness based on surface area minimum
1.5%Loss on ignition, max %0.1%EN196-21Chloride, max %
68% minimumBS196-2Total SiO2, min %-EN197-1Reactive SiO2 min %
LimitsTest methodProperty
[1] Limit values for single results are 70% and 80% respectively[2] Current limit 50% in EN450. The limit has been reduced to 30% and this is out for comment at present
ConGlassCrete – High Value Use of Waste Glass in Concrete Products
Key limits for ground glass as a pozzolana
Maximum 0.1% PbOMaximum 1 ppm CdO
XRF or solution methods
Lead levels (and other metals) maximum
< 120 minutes more than cement (at 30% replacement) and not less
than cement aloneEN 196-3Initial setting time
Not more than cement + 3%BS 3892 EWater requirement, max. percentage of control
-BS 3892 CMoisture content, max, %-EN196-6Particle density, min kg.m-3
LimitsTest methodProperty
ConGlassCrete – High Value Use of Waste Glass in Concrete Products
Frequency of testing for ground glass pozzolana
• Difficult to be definitive about the level of factory production control required
• Most frequent tests likely to be required are: Fineness (at least once a day on a routine basis) Soundness Strength activity Index Setting time
• Tests for silica, chloride, lead and other metals are likely to be required less frequently than for the parameter listed above.
ConGlassCrete – High Value Use of Waste Glass in Concrete Products
Conclusion
• Ground glass pozzolana judged “fit for purpose” and suitable for use as a pozzolanic replacement to cement.
• Levels of replacement up to 25 % (by weight of cementitious material) likely to be achievable.
• Durability not covered by the pre-certification assessment. Further work needed to extend the range of claims made for the material
ConGlassCrete – High Value Use of Waste Glass in Concrete Products
Concrete Products
Pre-certification testing
ConGlassCrete – High Value Use of Waste Glass in Concrete Products
Concrete Products
Glass pozzolanaThree test mixes and a standard or control mixPaving blocks
WPC, blue glass aggregate, metakaolinOne test mixDecorative masonry
blocks
Green glass pozzolana, aggregate from post consumer cullet from pub and
pub collection
Three test mixes and one control mixMasonry blocks
Glass contentMixesProduct
ConGlassCrete – High Value Use of Waste Glass in Concrete Products
Grey Masonry Blocks(Stowell Concrete Ltd)
ConGlassCrete – High Value Use of Waste Glass in Concrete Products
Paving Blocks(Aggregate Industries UK)
ConGlassCrete – High Value Use of Waste Glass in Concrete Products
Masonry Units(CRH Forticrete)
ConGlassCrete – High Value Use of Waste Glass in Concrete Products
Essential characteristics for Grey Blocks: BS 6073-1:1981
≤ 0.09%Drying Shrinkage
a) ≥ 7.0 N/mm2
b) ≥ 0.9*7.0 + 0.62*S (N/mm2), S is the standard deviation for the sample
Compressive Strength
Maximum deviation:Length: +3mm -5mmHeight: +3mm -5mm
Thickness: +2mm -2mm average+4mm -4mm individual
Dimensional Check
CriteriaProperties
ConGlassCrete – High Value Use of Waste Glass in Concrete Products
Essential characteristics for Architectural Masonry Units: BS
6073-1:1981
?Freezing-thawing
≤ 0.09%Drying Shrinkage
≥ 0.65 N/mm2Transverse Strength
a) ≥ 7.0 N/mm2
b) ≥ 0.9*7.0 + 0.62*S (N/mm2), S is the standard deviation for the sample
Compressive Strength
Maximum deviation:Length: +3mm -5mmHeight: +3mm -5mm
Thickness: +2mm -2mm average+4mm -4mm individual
Dimensional Check
CriteriaProperties
ConGlassCrete – High Value Use of Waste Glass in Concrete Products
Essential characteristics for Paving Blocks: BS 6717:2001, BS
EN 1338:2003
Manufacturer’s declared valueS4≥45S3≥35S2
No performance determinedS1Mean valueClass
Slip/Skid Resistance
23mmA2No performance determinedA1
Degree of abrasionClassAbrasion
Resistance
≥ 3.9 N/mm2 average≥ 2.9 N/mm2 individual
≥ 250 N/m failure load, individual
Tensile Splitting Strength
Thickness <100mm: Length & width ± 2m, thickness ± 3mmThickness ≥100mm: Length & width ± 3m, thickness ± 4mm
Shape and Dimensions
CriteriaProperties
ConGlassCrete – High Value Use of Waste Glass in Concrete Products
Essential characteristics for Paving Blocks: BS 6717:2001, BS
EN 1338:2003 (continued)
No cracking, flaking or delaminatingAppearance Visual Aspects
Manufacturer’s declared valueW3≤1.0, no individual value >1.5W2No performance determinedW1
Mass loss after testmean value (kg/mm2)Class
Weathering Resistance
CriteriaProperties
ConGlassCrete – High Value Use of Waste Glass in Concrete Products
Conclusion
Concrete products tested complied with strength and drying shrinkage requirements of appropriate standards (BS 6073-1:1981, BS 6717:2001)
Concrete products containing glass had same performance classification as control mix (without glass)
ConGlassCrete – High Value Use of Waste Glass in Concrete Products
Full Approval: requirements include the following
• Manufacturers to independently submit formal application to BRE Certification. BRE Certification fees and timescale will be included in the proposal.
• Assessment of factory production control including initial visit to manufacturing location to check material sources, processing, traceability, compliance with limits etc
• Testing as required by relevant product standards/ Building Regulations
• Assessment of the product life expectancy (durability)
Preparation of draft certificate and circulation to BRE Certification Construction Board
ConGlassCrete – High Value Use of Waste Glass in Concrete Products
Thank you for your attention
• www.brecertification.co.uk
• www.bre.co.uk