DURABLE CONCRETE THROUGH USE OF PULP AND PAPER …DURABLE CONCRETE THROUGH USE OF PULP AND PAPER...

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.


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.


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.


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).


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.


Mill Wastewater Primary

Clarifier

Dewatering

Primary Residual

Secondary Residual

Clarified WaterSecondary

Clarifier

Dewatered Residual

Recovered Water

Paper Mill Wastewater Treatment Process


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


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.


Scanning electron micrograph of Residual C1


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.


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.


Residual Fiber Reinforcing a Micro-crack in Concrete


0100200300400500600700

Aspect RatioL/D

Tensile Strength(MPa)

Modulus ofElasticity (GPa)

SteelCarbonWood Cellulose

Properties of Micro-fibers


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.


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.


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.


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.


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.


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.


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.


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


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


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


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


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)


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


Construction Demonstration


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


Strength of Demonstration Concrete

2873

Age (Days)

6.251.84.941.44.432.5

Flexural Strength (MPa)

Compressive Strength (MPa)


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


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


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.


La Bella Terra


La bella terra


More information at<www.cbu.uwm.edu>.


Thank you very much for your

interest.


Merci BeaucoupAabhar Tamaro, Afcharisto Poly,Arigatou Gozaimasu, Dziekuje,

Maraming Salamat, Muchas GraciaGrazie Molte, Muito Obrigado,Salamat, Shukriya, Spasi Bo,

Thank you, Toda Raba.

DURABLE CONCRETE THROUGH USE OF PULP AND PAPER …DURABLE CONCRETE THROUGH USE OF PULP AND PAPER...

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