Upload
others
View
1
Download
0
Embed Size (px)
Citation preview
Center for By-Products Utilization
DURABLE CONCRETE THROUGH USE OF PULP AND PAPER MILL
RESIDUALS
by Yoon-moon Chun, Tarun R. Naik,
and Rudolph N. Kraus
Presented at the Presented at the Third International Conference on Composites in Construction, LyThird International Conference on Composites in Construction, Lyon, France, on, France, July 11July 11--13, 2005.13, 2005.
Center for By-Products Utilization
UWM Center for By-Products Utilization
Reduce, reuse, and recycle for sustainable developments.Minimize use of manufactured materials.
Maximize environmental benefits: clean air, clean water, and resource conservation.
Center for By-Products Utilization
Basic ApproachBasic ApproachWA$TE is wasted if you waste it, otherwise itWA$TE is wasted if you waste it, otherwise it
is a resource. Resource is wasted if you is a resource. Resource is wasted if you ignore it and do not conserve it with holistic ignore it and do not conserve it with holistic
best practices and reduce societal costs. best practices and reduce societal costs. Resource is for the transformation of people Resource is for the transformation of people
and society. and society.
Focus on turning brown fields into green Focus on turning brown fields into green fields of the 21fields of the 21stst Century. Century.
Center for By-Products Utilization
Basic ApproachBasic Approach
Recycle. Recycle as is.Recycle. Recycle as is.
Recycle without additional processing, Recycle without additional processing, (i. e., without adding any cost to it).(i. e., without adding any cost to it).
Center for By-Products Utilization
Center for By-Products Utilization
Pulp and Paper MillWastewater Treatment Residuals
• Solid residue removed from mill wastewater before the water is discharged or reused.
• Removed in two steps (primary and secondary).
• Usually, dewatered before disposal or beneficial use.
Center for By-Products Utilization
Mill Wastewater Primary
Clarifier
Dewatering
Primary Residual
Secondary Residual
Clarified WaterSecondary
Clarifier
Dewatered Residual
Recovered Water
Paper Mill Wastewater Treatment Process
Center for By-Products Utilization
0102030405060708090
100
Landfill Burn LandApply
Reuse Other
Res
idua
ls M
anag
ed(D
ry w
eigh
t %)
197919881995
Wastewater treatment residuals managementin the U.S. paper industry
Center for By-Products Utilization
Pulp and Paper Mill Residual Solids in Concrete
• Approximately half of the residual solids generated in the USA is sent to landfills.
• Because of cellulose fibers in the residual solids, the residual solids could become an economical source of fibers for use in concrete.
Center for By-Products Utilization
Scanning electron micrograph of Residual C1
Center for By-Products Utilization
Objectives • Establish technical, economical, and
performance benefits of using pulp and paper mill residual solids in ready-mixed concrete.
• Improve properties and durability of concrete.
• Determine effects on rheological properties of concrete due to chemicals in the residual solids.
Center for By-Products Utilization
Reasons for Fiber Reinforcement of Concrete
• Inherently, concrete is a brittle material.
• By incorporating fibers into concrete, its toughness and tensile strength can be improved; and, also, shrinkage cracking can be reduced, leading to durable concrete and sustainable concrete structures.
Center for By-Products Utilization
Residual Fiber Reinforcing a Micro-crack in Concrete
Center for By-Products Utilization
0100200300400500600700
Aspect RatioL/D
Tensile Strength(MPa)
Modulus ofElasticity (GPa)
SteelCarbonWood Cellulose
Properties of Micro-fibers
Center for By-Products Utilization
Pulp and Paper Mill Residual Solids in Structural Concrete
• There have been very few investigations.• Best performance of concrete seems to be
achieved if the residual solids were collected prior to chemical conditioning and solidification.
Center for By-Products Utilization
Characteristics of Residuals
65.9 (43.6-99.6)LOI at 590°C (%)*57 (35-94)Wood Fiber (%)*
1.27 (0.85-1.68)Avg. Fiber Length, LL (mm)1.83 (1.56-2.17)Specific Gravity
153 (84-230)Moisture Content (%)*5 Virgin, 1 Recycled, 1 MixedFiber Origin
6 Primary, 1 Fiber reclaimType of Residual
* % of oven-dry mass.
Center for By-Products Utilization
De-Flocculating Experiments• Residual solids need to be de-flocculated
before they can be used in concrete.
• Mechanical mixing with water using high-shear mixer was most effective.
• Hot water could be used to improve mechanical de-flocculation.
Center for By-Products Utilization
Center for By-Products Utilization
Concrete Laboratory Mixtures• Determined the pattern of strength
development of concrete containing residual solids.
• Determined effects of amounts of residuals and HRWRA on the strength of concrete.
• Developed concrete mixtures with comparable strength by adjusting water content.
Center for By-Products Utilization
Concrete Laboratory Mixtures (cont’d.)
• With the use of HRWRA, it was possible to obtain structural-grade concrete with up to a 0.65% as-received residual content.
• At the residual content of 0.65%, the strength of concrete was nearly uniform at all ages regardless of residual content.
Center for By-Products Utilization
Concrete Laboratory Mixtures (cont’d.)
• Amount of residuals in concrete may be significantly increased above 0.65%; projected to 1.5%.
• The key to obtaining uniform concrete strength regardless of residual content was to maintain a consistent concrete density.
Center for By-Products Utilization
Durability of Concrete Containing Residual Fibers
–Residual content up to 0.65%.– Initial and final setting times evaluated.–Air-entraining admixture (AEA) was
NOT used.–HRWRA was used to adjust slump.
Center for By-Products Utilization
Mixture Proportions (per m3) and Fresh Properties
159156151158158162156149156Water (kg)
1.81.32.31.91.71.81.62.81.6Air Content (%)
75901257512518015090115Slump (mm)
0.440.420.410.430.440.450.430.410.43W/Cm
10301050104010501030102010301030105019-mm Crushed Stone (kg)
841855847852841836848837856Sand (kg)
2400
3592.215.6
WG
2410
3613.415.7
WV
2420
3670.80
Ref2
2410
3651.58.5
BR
24102440242023902430Density (kg/m3)
363368363360368Cement (kg)5.53.53.01.80.8HRWRA (L)
15.716.015.715.60Residuals (kg)
SIC2C1Ref1Mixture Name
Center for By-Products Utilization
Strength and Durability Testing• Compressive Strength
– Effect of residual solids on compressive strength of concrete• ASTM C 39
• Length Change– Effect of residual solids in concrete on drying
shrinkage• ASTM C 157
Center for By-Products Utilization
Strength and Durability Testing (cont’d)
• Resistance to De-icing Chemicals– Evaluation of concrete surface exposed to de-icing
solution while subjected to freezing and thawing cycling• ASTM C 672
• Resistance to Freezing and Thawing Cycling– Evaluation of internal cracking/microstructure
by measurement of dynamic modulus of elasticity• ASTM C 666 Procedure A
Center for By-Products Utilization
0
10
20
30
40
50
60
0 20 40 60 80 100
Age (days)
Com
pres
sive
Stre
ngth
(MPa
)Ref. 1C1C2WGWV
Compressive strength of concrete
Center for By-Products Utilization
0
10
20
30
40
50
60
0 20 40 60 80 100Age (days)
Com
pres
sive
Stre
ngth
(MPa
)
Ref. 2BRIS
Compressive strength of concrete (cont’d)
Center for By-Products Utilization
Length change of concrete due to curing in water and drying in air
-0.06-0.05-0.04-0.03-0.02-0.010.000.010.02
0 50 100 150 200 250
Age (days)
Len
gth
Cha
nge
(%)
Ref. 2BRIS
Center for By-Products Utilization
Construction Demonstration
Center for By-Products Utilization
Mixture Proportions (per m3) and Fresh Properties
119Water (kg)
3.0Air Content (%)210Slump (mm)0.36W/Cm
105019-mm Gravel (kg)860Sand (kg)
2370Density (kg/m3)
329Cement (kg)1.77HRWRA (L)11.6Residuals (kg)*
C1 FieldMixture Name
* 0.49% on the mass of concrete
Center for By-Products Utilization
Center for By-Products Utilization
Center for By-Products Utilization
Center for By-Products Utilization
Center for By-Products Utilization
Center for By-Products Utilization
Center for By-Products Utilization
Center for By-Products Utilization
Strength of Demonstration Concrete
2873
Age (Days)
6.251.84.941.44.432.5
Flexural Strength (MPa)
Compressive Strength (MPa)
Center for By-Products Utilization
95
96
97
98
99
100
0 60 120 180 240 300
Freezing-and-Thawing Cycles
Rel
ativ
e D
ynam
ic M
odul
us o
fEl
astic
ity (%
)
Freezing-and-thawing resistance of concrete used for non-air-entrained field demonstration
Center for By-Products Utilization
0
1
2
3
4
5
0 10 20 30 40 50
Salt-Scaling Cycles
Scal
ing
Rat
ing
No Scaling
Severe Scaling
Salt scaling of concrete used for non-air-entrainedfield demonstration
Center for By-Products Utilization
CONCLUSIONSIn general, addition of residual solids in concrete
•• did not affect dryingdid not affect drying--shrinkage,shrinkage,•• improved freezingimproved freezing--andand--thawing thawing
resistance, andresistance, and•• improved saltimproved salt--scaling resistance.scaling resistance.
Center for By-Products Utilization
La Bella Terra
Center for By-Products Utilization
La bella terra
Center for By-Products Utilization
Center for By-Products Utilization
More information at<www.cbu.uwm.edu>.
Center for By-Products Utilization
Thank you very much for your
interest.
Center for By-Products Utilization
Merci BeaucoupAabhar Tamaro, Afcharisto Poly,Arigatou Gozaimasu, Dziekuje,
Maraming Salamat, Muchas GraciaGrazie Molte, Muito Obrigado,Salamat, Shukriya, Spasi Bo,
Thank you, Toda Raba.