MECHANISM OF ACTION OF CAE SUPERPLASTICIZERS Francesco Surico, R&D Mapei SpA, Milano Technical...

MECHANISM OF ACTION OF CAEMECHANISM OF ACTION OF CAESUPERPLASTICIZERSSUPERPLASTICIZERS

Francesco Surico, R&D Mapei SpA, Francesco Surico, R&D Mapei SpA, MilanoMilano

Technical Briefing on Concrete Admixture – S. Petersburg, August 1 2007

HISTORY OF SUPERPLASTICIZERS

1936

SO3Na

CH2

Condensation polymer between naphthalenesulfonic acid and

formaldehyde

NAPHTALENESULFONATE

PNS BNS NS

NSFC NS

US Pat. N. 2,052,586 Sept. 1, 1936 G. Tucker (GRACE)

Negative Negative chargedchargedgroupgroup

-

SO3Na

CH2

SO3Na

CH2

SO3Na

CH2

SO3Na

CH2

SO3Na

CH2

--

-

-

-

1938


LIGNOSULFONATE LGS LS

US Pat. N. 2,141,570 Dec. 27, 1938 Jacob G. Mark

Chemical modification (sulfonation)

of natural lignine

C C CO

OH H OH

HO OCH3H HSO3Na

C C CO

OH H OH

HO OCH3H HSO3Na

C C CO

OH

H

OH

HO OCH3H H

SO3Na

-

-

-

-

C C CO

OH OH

HO OCH3H SO3Na

n


60’s


SO3Na

CH2

Condensation polymer between naphthalenesulfonic acid and

formaldehyde

NAPHTALENESULFONATE

PNS BNS NS

NSFC NS


-

SO3Na

CH2

SO3Na

CH2

SO3Na

CH2

SO3Na

CH2

SO3Na

CH2

--

-

-

-

n

GB Pat. N. 1391818 Kenichi Hattori (KAO Corp.)

Condensation polymers between melamine

sulfonate and formaldehyde

MELAMINE SULFONATE CONDENSATE

MS MSFC

German Patent # 1745441 Aignesberger (SKW)

N

N N

CH2 SO3 Na

NH CH2OCH2 HN

n-

N

N N

CH2 SO3 Na

NH CH2OCH2 HN

N

N

N

CH2 SO3 Na

NH CH2OCH2 HN

N N

N

CH2 SO3 Na

NH CH2OCH2 HN

N

N

N

CH2 SO3 Na

NH CH2OCH2 HN

-

-

-

-



Reasons of the success of Super’s in the 80’s

improvement of the quality and efficiency of the new improvement of the quality and efficiency of the new polymers with consequent enhancement of the polymers with consequent enhancement of the performance-cost factor;performance-cost factor;

1.1.

Evidence that superplasticizers do not create long Evidence that superplasticizers do not create long term problems in concrete;term problems in concrete;

2.2.

Establishment of technical requirements for higher Establishment of technical requirements for higher performance concrete with need of superplasticizers;performance concrete with need of superplasticizers;

3.3.

Rapid growth of the demand for either “flowing Rapid growth of the demand for either “flowing concrete” and/or high strength/high performance concrete” and/or high strength/high performance concrete by the construction industryconcrete by the construction industry

4.4.


1936 - 1993

1936 - 1993

FIRST

AND SEC

OND

FIRST

AND SEC

OND

SUPERPLA

STICIZ

ERS

SUPERPLA

STICIZ

ERS

GENER

ATION A

GE

GENER

ATION A

GE

1994

Copolymer of acrylic acids and acrylic ethoxylate esters

In 1994 MAPEI, first in Europe, starts the production of MAPEFLUID X404

Non ionic Non ionic groupgroup


C C CC C C

C CCO OO

OX

n

_

Third Third monomermonomer

with MAPEFLUID X404 starts the new

age of third generation

superplasticizers in Europe

CO

O

C C C C

C CO O

ONaO

C C C C

C CO O

ONaO

C C C C

C O

ONa

C C C C

C O

ONa

CO

O

-- - -

POLYCARBOXYLATES POLYETHERS

ACRYLICS CAE PCA PCE

Different technology may be used to produce this class of molecules.

Non ionic Non ionic groupgroup


4. Non ionic group molecular weight

2. Polymer molecular weight

3. Ratio Acid groups/Ester groups (A/E)

1. Type of monomers

C C CC C C

C CCO OO

OX

n

_

Third Third monomermonomer

POLYCARBOXYLATEPOLYETHERS

ACRYLICS CAE PCA PCE

-- -- -

-- -- - -- -- -

The key factors differentiating the polymers are:

-Length of the Main chain

- Length of the side chain

- Charge density on the main chain

STATE OF THE ART OF SUPERPLASTICIZERS

MAPEI Vs. MAIN COMPETITORS’ TECHNOLOGY

BASF SIKA MAPEI



BASF

- They started (1996) with Japanese technology because of Mapei Intl. Patent (pay royalties)

- Today, thanks to SKW and BASF move to different SKY technology. Same molecule design but different production method (new patent)

- To cut cost factor, SKY have maximum water reduction (risk of bleeding and segregation) and sugar based formulas to allow workability retention



BASF

- STRENGTH: Big company fully integrated with all the monomers, lower raw material costs

- WEAKNESS: Low flexibility. Two-three polymers and many blends with retardants and other chemicals



SIKA

- They started later with different technology of production

- Only one polymer ( suitable for ready mix) with limited possibility to vary the side chain length and the charge density

- For precast not available a own polymer higer cost to buy outside (from BASF too).



SIKA

- STRENGTH: Low cost of production and good compatibilty of polymer with some blended cements for ready mix concrete

- WEAKNESS: Not competitive in Precast on performance/cost ratio.Problems of degradation of their polymers with uncontrolled results in ready mix concrete



STRENGTH: Strong effort in R&D to develop new specialised polymers. Ready Mix – PrecastFlexibility of the production technology

MAPEIWEAKNESS: Higher raw material costs due to customised production technology

KEY FACTOR FOR SUCCESS

SELECT THE MOST SUITABLE PRODUCT FOR

EVERY APPLICATION

- Knowledge of the available product range

- Collection of as much technical information as

possible before to job site testing

- Choice of the most efficient cost/performance

ratio solution

CEMENT-SUPERPLASTICIZERINTERACTION

Cement HydrationRetention of workability

Cement dispersion

ETTRINGITE

ANHYDROUS CEMENT

C-S-H FIBERS

POLYMER ONTO THE CEMENT SURFACE (ADSORPTION)11

-- --- -- ----- ---

-- ----- ---

-- ---

-- ---

-- ----- ---

-- ---

22 POLYMER INTO ETTRINGITE (ORGANOMINERAL PHASE - OMP)

-- --- -- ---

-- ---

-- ---

-- ---

-- ---

-- ---

-- ----- ---

UNADSORBED POLYMER IN THE SOLUTION

33

-- ---

-- ---

-- ---

-- ---

-- ---

-- ---

-- ---

-- ----- ---

-- ---

-- ---

THE POLYMER FRACTIONS LEFT IN THE SOLUTION AND

THAT INCORPORATED INTO THE EARLY HYDRATION PHASE

HAVE BEEN ALWAYS CONSIDERED LOST AS

SUPERPLASTICIZERS BECAUSE NOT ACTIVE IN TERMS OF

FLUIDIFYING EFFECT

SINCE 1994 MAPEI STUDIED THE

INTERACTIONS OF THESE FRACTIONS

WITH CEMENT AND FOUND THAT THEY

CAN AFFECT MANY OTHER PROPERTIES

OF CEMENTITIOUS SYSTEMS

Polymer onto cement surface

Polymer in solution

Polymer incorporated in the hydration

products

ADSORPTION

EQUILIBRIUM

FLUIDIFYING EFFECT

RETENTION OF WORKABILITY

HYDRATION

MECHANICAL STRENGTH

MAPEI HOLISTIC APPROACH


Polymer in solution


products

ADSORPTION

EQUILIBRIUM

FLUIDIFYING EFFECT


HYDRATION

MECHANICAL STRENGTH

-+

+

+

++

-

-

--

-

RHEOLOGY OF CEMENT WITHOUT SUPERPLASTICIZERS

Pot

enti

al E

nerg

y

REPULSION

ATTRACTION

Distance

-+

+

+

++

-

-

--

-

-+

+

+

++

-

-

--

-

Pot

enti

al E

nerg

y

REPULSION

ATTRACTION

Distance

-+

+

+

++

-

-

--

-

FLOCCULATION

HIGH VISCOSITY

RHEOLOGY OF CEMENT WITHOUT SUPERPLASTICIZERS

DISPERSION OF CEMENT PARTICLES BY DISPERSION OF CEMENT PARTICLES BY ELECTROSTATIC REPULSIONELECTROSTATIC REPULSION

Main polymer chain

Sulfonic groups (negatively charged) “anchoring groups”

ADSORPTIONADSORPTION

Cement particle

MECHANISM OF WORKING OF FIRST AND SECOND GENERATION SUPERPLASTICIZERS

----

---

--

---------

---------

----- ----

----

---

--

- -- -

-- -

- -

- - - - -- - - -

- - - - -- - - -

- - - - -- - --

-----

----

----

---

--

---------

---------

----- ----

----

---

--

- -- -

-- -

- -

- - - - -- - - -

- - - - -- - - -

- - - - -- - --

-----

----

Pot

enti

al E

nerg

y

REPULSION

ATTRACTION

Distance

RHEOLOGY OF CEMENT WITH 1^ AND 2^ GENERATION SUPERPLASTICIZERS

___ __ _

_ __ _

_ __ _

_ __ _____

_ __ _

_ __ _

_ __ _

_ __ ___

___ __ _

_ __ _

_ __ _

_ __ ___

___ __ _

_ __ _

_ __ _

_ __ ___

MECHANISM OF WORKING OF FIRST AND SECOND GENERATION SUPERPLASTICIZERS

DEFLOCCULATION - LOW VISCOSITY MIXTURE DEFLOCCULATION - LOW VISCOSITY MIXTURE

___ __ _

_ __ _

_ __ _

_ __ ___

___ __ _

_ __ _

_ __ _

_ __ ___

___ __ _

_ __ _

_ __ _

_ __ ___

___ __ _

_ __ _

_ __ _

_ __ ___

ELECTROSTATIC ELECTROSTATIC REPULSIONREPULSION

----

---

--

---------

---------

----- ----

----

---

--

- -- -

-- -

- -

- - - - -- - - -

- - - - -- - - -

- - - - -- - --

-----

----

----

---

--

---------

---------

----- ----

----

---

--

- -- -

-- -

- -

- - - - -- - - -

- - - - -- - - -

- - - - -- - --

-----

----

Pot

enti

ual

En

erg y

REPULSION

ATTRACTION

Distance

ELECTROSTATIC REPULSION

RHEOLOGY OF CEMENT WITH 1^ AND 2^ GENERATION SUPERPLASTICIZERS

LOW VISCOSITY

Polymerbackbone chain

Carboxylate groups (negative charges)

“anchoring groups”

Neutral side chains “steric springs”

Cement grain

ADSORPTION

MECHANISM OF WORKING OF THIRD GENERATION SUPERPLASTICIZERS

DISPERSION OF CEMENT PARTICLES BY DISPERSION OF CEMENT PARTICLES BY ELECTRO-STERIC REPULSIONELECTRO-STERIC REPULSION

Pot

enti

al E

nerg

y

REPULSION

ATTRACTION

Distance

-----

- ----

----- -----

--- --

--- --

---- - -- -- ---

-- -

-----

- ----

----- -----

--- --

--- --

---- - -- -- ---

-- -

RHEOLOGY OF CEMENT WITH 3^ GENERATION SUPERPLASTICIZERS

ELECTROSTERIC REPULSION --

---

- ----

----- -----

--- --

--- --

---- - -- -- ---

-- ---

---

- ----

----- -----

--- --

--- --

---- - -- -- ---

-- -

Pot

enti

al E

nerg

y

REPULSION

ATTRACTION

Distance

RHEOLOGY OF CEMENT WITH 3^ GENERATION SUPERPLASTICIZERS

VERY LOW VISCOSITY

THE THE SIMULTANEOUS SIMULTANEOUS PRESENCE OF PRESENCE OF NEGATIVE NEGATIVE CHARGES AND CHARGES AND NON IONIC NON IONIC GROUPS IN THE GROUPS IN THE POLYMER POLYMER MOLECULE MOLECULE ENHANCE THE ENHANCE THE DISPERSING DISPERSING CAPABILITY OF CAPABILITY OF THE POLYMERTHE POLYMER



Polymer in solution


products

ADSORPTION

EQUILIBRIUM

FLUIDIFYING EFFECT


HYDRATION

MECHANICAL STRENGTH

Cement is an hydraulic binder based on pulverized clinker and gypsum, that is added in the grinding stage to regulate set.After the thermal process (1400 °C) the main constituents of a portland clinker are:

Tricalcium Silicate (3CaO•SiO2) C3S

Dicalcium Silicate (2CaO•SiO2) C2S

Tricalcium Aluminate (3CaO•Al2O3) C3A

Ferrite Phase (4CaO•Al2O3•Fe2O3) C4AF

Hydration of the different phases of cement involves many complex chemical reactions that occur simultaneously when in contact with water.

Rate of the hydration reaction of the different phases:

C3A > C4AF C3S > C2S

Hydration of the faster C3A and C4AF leads to cement set.

Hydration of the slower C3S and C2S leads to cement hardening.

HYDRATION OF THE ALUMINA PHASES

These reactions are almost instantaneous and would lead to flash set of cement in

the absence of gypsum.

C3A + 3CSH2 + 26H = C3A•3CSH32 (ettringite)

C4AF undergoes to similar reactions

0

5

10

15

20

25CS (MPa)

CEMENT HYDRATION MECHANISM

21,5

22,5

23,5

24,5

25,5

0 5 10 15 20 25time (h)

Alumina Phase Hydration - Instantaneous - Produces the setting of cement

Hydration of Siliceous Phase - Slow - Produces the hardening of cement

92 % r.h.

OPC type I paste after 5 min

0 5 10 15 20 25

OPC type I paste after 1 hour

0 5 10 15 20 25

OPC type I paste after 5 hours

0 5 10 15 20 25

-- -- -

-- -- -

26

20

22

24

28

30

0 5 10 15 20 25

time (h)

T(°C)

ALUMINA PHASE HYDRATION - OMP FORMATION --

---

-----

-- -- ---- --

----- --

---

--- --

-- -- -

--- -- --- --

-----

--- --

-- -- -

-- -- --- -- -

-- -- -

-- -- -

-- -- -

DORMANT PERIOD

C3S, C2S

SILICEOUS PHASE HYDRATION C-S-H FORMATION - MECHANICAL

STRENGTH DEVELOPMENT

ALUMINA PHASE HYDRATION - OMP FORMATION

-----

-----

-- -- -

-- -- -

-- -- --- -- -

-- -- --- -- -

-----

-- -- --- -- - --

---

-----

-- -- -

-----

-- -- -

20

22

24

26

28

30

0 5 10 15 20 25

time (h)

T(°C)

-- -- -

-- -- - -- -- - -- -- - -- -- -

-- -- --- -- - -- -- -

DORMANT PERIOD

C3S, C2S

SILICEOUS PHASE HYDRATION C-S-H FORMATION - MECHANICAL STRENGTH DEVELOPMENT

20,00

22,00

24,00

26,00

28,00

30,00

0 5 10 15 20 25

time (h)

T(°C)

HYDRATION OF SILICEOUS PHASE CONTROLS HYDRATION OF SILICEOUS PHASE CONTROLS THE MECHANICAL STRENGTH DEVELOPMENTTHE MECHANICAL STRENGTH DEVELOPMENT

NO

RM

AL

NO

RM

AL

RETA

RD

ING

RETA

RD

I NG

AC

CELER

ATED

AC

CELER

ATED



Polymer in solution


products

ADSORPTION

EQUILIBRIUM

FLUIDIFYING EFFECT


HYDRATION

MECHANICAL STRENGTH

---- -

-----

-- -- -

-- -- -

-- -- -

-- -- -

-- -- --- -- -

---- -

-- -- -

---- -

---- -

---- -

---- -

-----

-----

---- -

-- -- - ---- -

---- -

---- -

HIGH ADSORPTION RATEHIGH ADSORPTION RATE


0 5 10 15 20 25

-- -- -

-----

----- ----- --------------- --------------- ----- --------------- ----- ---------------

----------

--------------------

---------------

------------------------- ---------------

----------

--------------------

-----

--------------------

-----

-------------------------

----------

--------------- -----

-----


0 5 10 15 20 25

----- ----- --------------------

----------

----------

--------------- -----


0 5 10 15 20 25

----- ---------- ---------------

0

50

100

150

200

250

0 30 60 90 120 150

TIME (minutes)

SL

UM

P (

cm)

-----

-- -- -

-- -- -

-- -- -

-- -- -

-- -- -

---- -

---- -

---- -

---- -

-----

-----

-- -- -

-- -- ---

-- -

---- -

---- -

-- -- -

---- -

---- -

---- -

---- -

---- -

---- -

---- -

---- -

---- - --

-- -

CONTROLLED ADSORPTION RATECONTROLLED ADSORPTION RATE

CONTROLLED ADSORPTION RATECONTROLLED ADSORPTION RATE

--

--

-

--

--

-


0 5 10 15 20 25

----- ----- --------------- --------------- ----- --------------- ----- ---------------

----------

--------------------

---------------

------------------------- ---------------

----------

--------------------

-----

--------------------

-----

-------------------------

----------

--------------- -----

-----

0

50

100

150

200

250

0 30 60 90 120 150

TEMPO (minuti)

SL

UM

P (

cm)

SUPERPLASTICIZERS WITH THE DESIRED SUPERPLASTICIZERS WITH THE DESIRED

CHARACTERISTICS MAY BE OBTAINED BY CHARACTERISTICS MAY BE OBTAINED BY

PROPERLY SELECTING AND COMBINING THE PROPERLY SELECTING AND COMBINING THE

RAW MATERIALS IN ORDER TO MEET THE RAW MATERIALS IN ORDER TO MEET THE

REQUIREMENTS FOR THE SPECIFIC REQUIREMENTS FOR THE SPECIFIC

APPLICATIONAPPLICATION

MONOMERS MONOMERS AND RAW AND RAW

MATERIALSMATERIALSSYNTHESIS SYNTHESIS

INTERMEDIATES INTERMEDIATES PRODUCTIONPRODUCTION

SYNTHESIS SYNTHESIS INTERMEDIATES INTERMEDIATES

PRODUCTIONPRODUCTION

POLYMERPOLYMER


POLYMERPOLYMER


SELLSELLSELLSELL

R & DR & D

Pot

enti

al E

nerg

y

REPULSION

ATTRACTION

Distance

STUDY ON ADSORPTION

OPTIMISATION OF ELECTROSTERIC EFFECT

NEW POLYMERS WITH IMPROVED FLUIDIFYING EFFECTDynamon SP1Dynamon SP1

Dynamon SXDynamon SX

MODIFICATION OF ETTRINGITE NANO-STRUCTURE

STUDY ON HYDRATION

20,00

22,00

24,00

26,00

28,00

30,00

0 5 10 15 20 25

time (h)

T(°C)

NEW POLYMER WITH CONTROLLED DEVELOPMENT OF MECHANICAL STRENGTH

Dynamon SP3Dynamon SP3

Dynamon NRGDynamon NRG

CONTROL OF THE RATE OF ADSORPTION

NEW POLYMERS WITH HIGH RETENTION OF WORKABILITY

STUDY ON SOLUTION EQUILIBRIUM

-- ---

-- ---

-- ---

-- ---

-- ---

-- ---

-- ----- ---

-- ---

-- --- -- ---

-- ---

-- ----- ---

-- --- -- ---

Dynamon SR1Dynamon SR1 Dynamon SR3 Dynamon SR3

Dynamon SR2Dynamon SR2 Dynamon SR4Dynamon SR4

DPP DPP SUPERPLASTICIZERS SUPERPLASTICIZERS

FOR READY MIX CONCRETEFOR READY MIX CONCRETE

DPPDPP SUPERPLASTICIZERS SUPERPLASTICIZERS

FOR PRECAST CONCRETEFOR PRECAST CONCRETE

MECHANISM OF ACTION OF CAE SUPERPLASTICIZERS Francesco Surico, R&D Mapei SpA, Milano Technical...

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