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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
HISTORY OF SUPERPLASTICIZERS
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
Negative Negative chargedchargedgroupgroup
60’s
HISTORY OF SUPERPLASTICIZERS
SO3Na
CH2
Condensation polymer between naphthalenesulfonic acid and
formaldehyde
NAPHTALENESULFONATE
PNS BNS NS
NSFC NS
Negative Negative chargedchargedgroupgroup
-
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
-
-
-
-
Negative Negative chargedchargedgroupgroup
HISTORY OF SUPERPLASTICIZERS
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.
HISTORY OF SUPERPLASTICIZERS
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
Negative Negative chargedchargedgroupgroup
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
Negative Negative chargedchargedgroupgroup
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
STATE OF THE ART OF SUPERPLASTICIZERS
MAPEI Vs. MAIN COMPETITORS’ TECHNOLOGY
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
STATE OF THE ART OF SUPERPLASTICIZERS
MAPEI Vs. MAIN COMPETITORS’ TECHNOLOGY
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
STATE OF THE ART OF SUPERPLASTICIZERS
MAPEI Vs. MAIN COMPETITORS’ TECHNOLOGY
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).
STATE OF THE ART OF SUPERPLASTICIZERS
MAPEI Vs. MAIN COMPETITORS’ TECHNOLOGY
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
STATE OF THE ART OF SUPERPLASTICIZERS
MAPEI Vs. MAIN COMPETITORS’ TECHNOLOGY
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 onto cement surface
Polymer in solution
Polymer incorporated in the hydration
products
ADSORPTION
EQUILIBRIUM
FLUIDIFYING EFFECT
RETENTION OF WORKABILITY
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
MAPEI HOLISTIC APPROACH
Polymer onto cement surface
Polymer in solution
Polymer incorporated in the hydration
products
ADSORPTION
EQUILIBRIUM
FLUIDIFYING EFFECT
RETENTION OF WORKABILITY
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
MAPEI HOLISTIC APPROACH
Polymer onto cement surface
Polymer in solution
Polymer incorporated in the hydration
products
ADSORPTION
EQUILIBRIUM
FLUIDIFYING EFFECT
RETENTION OF WORKABILITY
HYDRATION
MECHANICAL STRENGTH
---- -
-----
-- -- -
-- -- -
-- -- -
-- -- -
-- -- --- -- -
---- -
-- -- -
---- -
---- -
---- -
---- -
-----
-----
---- -
-- -- - ---- -
---- -
---- -
HIGH ADSORPTION RATEHIGH ADSORPTION RATE
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 2 hours
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
--
--
-
--
--
-
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 2 hours
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
PRODUCTIONPRODUCTION
POLYMERPOLYMER
PRODUCTIONPRODUCTION
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