Test Report of Metakaolin
At present, metakaolin, as the high active mineral additive of concrete, is widely used
in the production. The content of SiO2 and Al2O3 is very high. Besides the filling
reaction of metakaolin powder and hydration promotion for portland cement, SiO 2
and Al2O3 react with Ca(OH)2 , then form C-S-H polymer, hydrated calcium aluminate
and Calcium sulfoaluminate hydrates. As it has very high pozzolanic activity, so it’s
also named Super volcanic ash.
Inner Mongolia Super Kaolin Co.,Ltd is specially producing and distributing
superfine calcined kaolin industry. KAOPOZZ TM metakaolin is produced with high
quality raw material, with several purification process, calcined under certain
condition, then produced cream white metakaolin (Al2O3.2SiO2), with extremely high
volcanic activity. China Building Material Academy tested KAOPOZZ TM sample,
present the application and technical properties of KAOPOZZ TM used in mortar and
cement for the promotion and application in future’s project. The main test results are
as following:
I. KAOPOZZTM K1100 Physical and Chemical Analysis
1. Test material
Metakaolin: Inner Mongolia Super KAOPOZZTM K1100, Particle Size:1250mesh
Silica Fume: Produced in Gansu.
2. Test method
Test SiO2 content and specific area (BET nitrogen adsorption method) according to
Appendix A of GB/T18736-2002<High Strength And Activity Cement Additive>;
Test Cl- content according to JC/T420<Cl- Chemical Analysis In Cement Raw
Material>;Test Al2O3, Fe2O3, CaO, MgO and total amount of alkali according to
GB/T176<Cement Chemical Analysis>.
3. Analysis of test result
1
The physical and chemical test table 1 between KAOPOZZTMK1100 Metakaolin and silica
fume.
Table 1 Material Physical and Chemical Analysis
SiO2 Al2O3 Fe2O3 CaO MgO Cl- Total amount of Specific Area
Item
% % % % % % alkali,% m2/g
Metakaolin 54.66 40.19 0.84 0.12 0.084 0.0037 0.32 15.1
Silica fume 94.48 / / / / 0.013 / 18.7
TM
Analyse the Form 1 test result, in KAOPOZZ K1100 metakaolin, Al2O3 is 40.19%,
and SiO2 is 54.66%, the active components are very high, it’s benefit to accelerate
cement hydration, improve the early strength of mortar and concrete. The specific
area is 15.1m2/g, the particle size is fine, so it’s good for the filling efficiency of
material. It have very low content of Cl - and total amount of alkali, if added into
mortar and concrete, it won’t affect the function. The silica fume from Gansu has
94.48% SiO2 and 19.32m2/g specific area, it means the silica fume is with high quality.
II. Mortar Test
1. Tested raw material
Metakaolin: Inner Mongolia Super KAOPOZZTMK1100, particle size 1250mesh.
Silica fume: From Gansu，the content of SiO2 is 94.48%.
Standard Sand: Accord with GB/T17671-1999<Strength test method for cement
&mortar(ISO)>.
Cement: GB8076-2008 <Concrete Admixture>, Test with base cement.P.I Portland
cement.
2. Test Method
According to the test method with Silica Fume introduced in GB/T18736-2002<High
Strength and High Performance Concrete Mineral Admixture>, test the activity of
metakaolin( add 0, 5%, 10%, 15% ,20%), Silica Fume from Gansu( add 10%), make
2
comparison of water demand and active index (3d, 7d, 28d).
3. Test result and analysis
For test result of mortar, see Table 2 and 3.
Teable 2 Mortar Mixture Test
No Metakaolin, Silica Standard Water, Mobility Water demand
Cement,g
. g Fume ,g Sand ,g g ,mm ratio, %
1 450 0 0 1350 225 184 /
2 427.5 22.5 / 1350 227 183 101
3 405 45 / 1350 240 181 107
5 382.5 67.5 / 1350 255 186 113
6 360 90 / 1350 263 183 117
7 405 / 45 1350 279 184 124
Table 3 Activity Index Test Results（%）
No. 3d 7d 28d
1 100 100 100
2 114 113 116
3 105 112 125
5 87 107 122
6 82 106 121
7 77 79 106
Analyse the test result in Form 2, the the increase of metakaolin
(5%,10%,15%,20%), to get the same mobility like base mortar( No.1) ， the water
demand increased from 227g to 263g. The water demand ratio increased from101% to
117%. This means KAOPOZZTMK1100 metakaolin has bigger specific area, so the
bigger water demand, so if added into mortar or concrete, will increase the water
demand. The mortar with 10% silica fume(NO.7), to get the same mobility like base
mortar( No.1) ， the water demand is 279g, the water demand ratio is 124%.
3
Compared the mortar with 10% metakaolin(No.3) and with 10% silica fume(No.7),
the water demand ratio with 10% metakaolin is 107%, and that with 10% Silica fume
is 124%. This means the water demand of KAOPOZZTMK1100 metakaolin is smaller
than silica fume.
Analyse the active test result in form 3, different adding quantity of
metakaolin(5%,10%,15%,20%), the active index are all higher. For that in 7d and 28d,
the active index are all over 100%, this means if add certain KAOPOZZ TMK1100
metakaolin into mortar and concrete, it will increase the compressive strength of
mortar and concrete. Compared the mortar with 10% metakaolin(NO.3) and 10%
silica fume(NO.7), the active index in 3d, 7d, 28d with 10% metakaolin are all higher
than that with 10% silica fume. That means for mortar application,
KAOPOZZTMK1100 metakaolin has higher active index than silica fume.
KAOPOZZTMK1100 metakaolin has higher active Al2O3, In the early stage of cement hydration,
the activity of Al2O3 was provided, then formed sufficient Needle like Calcium Vanadium Ore Crystal
aggregate structure, shorten cement setting time, accelerated hydration, to have higher early activity and
volcanic ash effect. Meanwhile because of the bigger specific area, finer particles, it has better filling effect.
TM
The mortar test result shows KAOPOZZ K1100 metakaolin has very high active index, the
quality is very good.
4
III. Concrete Test
1. The mixture and hardened concrete test
(1) Raw material for test
Cement: GB8076-2008 <Concrete Admixture>, Test with base cement.P.I Portland
cement.
River sand: the fineness modulus is 2.8 in the medium sand, continuous gradation
Rubble: 5~20mm continuous gradation
Metakaolin: Inner Mongolia Super KAOPOZZTMK1100 metakaolin, particle size
1250mesh.
Silica Fume: from Gansu
Poly carboxylic acid high performance water reducer: Shanxi Huangteng Chemical
CO.,Ltd. produced the early - consolidation poly carboxylic acid high performance
water reducer.
(2) Test Method
Test the concrete mixture properties(Slump, slump-loss, expansion, bleeding rate and
change of gas content) according to GB/T 50080-2002< Standard Test Method for the
performance of ordinary concrete>
Make compression test with GB/T50081-2002<Standard for test method of
mechanical properties of ordinary concrete>
Make test of concrete resistance to chloride ion permeability( Electric flux method),
rapid freezing and thawing test, and drying shrinkage test by GB/T50082-2009
<Standard for test method for long - term performance and durability of ordinary
concrete>.
(3) Test result and analysis
5
Choose the water - binder than 0.40 a different mixture ratio,added with different
amount of metakaolin (10%, 15%) and 8% silica fume in concrete and adjust the
additive dosage, and matched with the reference concrete group of the same
workability, to test concrete slump and slump loss, expansion, bleeding rate,
containing gas mixture , and for the hardened concrete, test intensity, flux, rapid
freezing and thawing and drying shrinkage.
Choose the water - binder than 0.30 a different mixture ratio,added with different
amount of metakaolin (10%, 15%) and 8% silica fume in concrete and adjust the
additive dosage, and matched with the reference concrete group of the same
workability, to test concrete slump and slump loss, expansion, bleeding rate,
containing gas mixture , and for the hardened concrete, test intensity, flux, rapid
freezing and thawing and drying shrinkage.
The water cement ratio is 0.40, 0.30 of the proportion and the results are shown in Table 4, 5.
6
freezing-
compressive strength，MPa thawing 300
Poly 28d 28d
Sand Contain 次
cement Meta Silica Rubble Water carbo- Expansi 30min electri Shrink
No , Slump bleeding in-g gas Dynami
, kaolin, fume, ，kg/ , xylic -on, Slump -c age
. kg/m , mm rate,% mixture - mass
kg/m3 kg/m3 kg/m3 m3 kg/m3 acid , mm , mm flux， value
3
, % 1d 3d 7d 28d 60d cmodu- loss
kg/m 3
C ×10-4
lus， ，%
%
1 430 0 0 745 1060 173 4.3 230 600 180 5.5 3.0 15.8 35.4 46.2 54.4 59.8 579 73.1 3.3 2.56
2 387 43 0 713 1092 173 4.6 215 510 170 0 3.2 15.7 42.3 55.2 67.6 70.9 389 83.2 2.2 2.40
3 365.5 64.5 0 695 1110 173 5.0 220 480 160 0 3.3 17.1 43.6 57.2 69.3 72.7 376 84.7 2.1 2.60
4 395.6 0 34.4 713 1092 173 4.8 215 500 160 0 3.4 15.6 39.9 51.6 64.2 68.4 441 80.3 2.8 2.76
Table 4 The property test result for 0.40 the water cement ratio Concrete and mixture Table 5
The property test result for 0.30 the water cement ratio Concrete and mixture
7
Poly
Expa Contain compressive strength，MPa 28d
Meta Silica Rubble carbo- 30min
No cement, Sand, Water, Slump nsi- bleedin in-g gas Shrinkag
kaolin fume, ，kg/ xylic Slump,
. kg/m3
kg/m 3
kg/m 3
, mm on, g rate,% mixture e value
, kg/m3 kg/m3 m3 acid , mm 1d 3d 7d 28d 60d
mm , % ×10-
kg/m3
5 504 0 0 700 1104 150 7 225 590 230 4.0 1.2 25.3 50.8 62.6 69.8 72.9 1.96
6 453.6 50.4 0 668 1136 150 7.6 220 550 200 0 1.7 23.4 51.3 73.3 81.2 85.7 2.20
7 428.4 75.6 0 650 1154 150 8.0 210 520 170 0 2.0 20.5 49.7 72.8 79.9 84.2 2.28
8 463.7 0 40.3 668 1136 150 7.6 220 575 205 0 1.8 18.8 48.9 64.9 76.4 82.1 2.66
8
Analyse the test result in table 4 and 5, because the specific area of silica fume and
metakaolin is bigger, so it affects the flowability of concrete, if increase the water
reducer slightly,can adjust concrete flowability. Add silica fume and metakaolin, can
improve the concrete bleeding performance, prevent bleeding and segregation. There
is no effect on concrete gas content when add silica fume and metakaolin.
Analysis from Table 4 test result, when the concrete water binder ratio is 0.4, add 15%
KAOPOZZTMK1100 metakaolin, can improve the early strength and later strength,
and the effect is better than the concrete with 8% silica fume. With
KAOPOZZTMK1100, the electric flux of the concrete is reduced, freeze-thaw
resistance and durability improved. The drying shrinkage value of concrete with 10%
and 15% metakaolin concrete is smaller than that with 8% silica fume. Can reduce the
risk of concrete shrinkage cracking.
Analysis from Table 5 test result, when the concrete water binder ratio is 0.3, add 10-
15% KAOPOZZTMK1100 metakaolin, can improve the early strength and later
strength, and the effect is better than the concrete with 8% silica fume. With
KAOPOZZTMK1100, the electric flux of the concrete is reduced, freeze-thaw
resistance and durability improved. The drying shrinkage value of concrete with 10%
-15% metakaolin concrete is smaller than that with 8% silica fume. The test result is
similar to that of water binder ratio 0.4.
Analysis KAOPOZZTMK1100 metakaolin add in concrete test, if add 10-15%
KAOPOZZTMK1100 metakaolin, just add admixture slightly, can compensate the loss
of working performance, increase the early strength and later strength, and improve
9
concrete durability.
2. Inhibition of alkali aggregate reaction activity test
(1) Raw material for test
Cement: GB8076-2008 <Concrete Admixture>, Test with base cement.P.I Portland
cement.
Rubble: from Sanhe, Hebei
High efficiency water reducer:Shanxi Huang Teng Chemical Co.,Ltd. Produce
naphthalene series high efficiency water reducer.
Sodium hydroxide: Analysis of pure sodium hydroxide
Metakaolin: Inner Mongolia Super KAOPOZZ TMK1100 metakaolin, particle size
1250mesh.
(2) Test Method
Make rubble alkali silica reaction activity test by GB ／T 14685-2011<Construction
with pebbles, gravel>.
Make the test of inhibition of the activity of alkali - silica reaction by GB／T 50733-
2011< Specification for preventing concrete alkali aggregate reaction>.
(3) Test result analysis
Before test, crush rubble to graded sand by GB/T14685-2011 and GB/T50733-2011.
During test, because of metakaolin, the mortar mobility is lowered, so add dosage of
high efficiency water reducer, to improve mortar mobility, meet the requirements of
mortar forming. The test result for the inhibition of the activity of the alkali - silica
reaction in the high efficiency are shown in table 6.
Table 6 Test results on the inhibition of the activity of alkali - silica reaction
10
High
Base Meta Graded efficiency 14d rate of
Water 10%Na2Oso Mobility
No Cement -kaolin gravel water expansion，
，g solution，g ，mm
，g ，g sand，g reducer， %
g
1 440 0 990 180.0 0 28.2 106 0.226
2 396 44 990 206.8 1.5 0 112 0.028
3 374 66 990 206.8 2 0 115 0.022
Analysis the test result of Table 6, The No.1 test result shows, the 14d expansion of
the rubble from Hebei Sanhe is 0.226%, is reactive aggregate for alkali silica reaction;
No.2 and 3 shows, after add 10%, 15% KAOPOZZ TMK1100 metakaolin, 14 d
expansion is 0.026% and 0.020%, all below 0.03%. According to the requirement of
GB/T 50733-2011, we can determine that add 10%,15% KAOPOZZ TMK1100
metakaolin can inhibit rubble Alkali - silica reaction activity. That means in the
construction if add KAOPOZZTMK1100, can inhibit alkali - silica reaction in concrete
aggregate.
3. 80℃ Steam curing test
（1）Raw material for test
Cement: Shaanxi conch P.O42.5R early strength portland cement
River sand: Jixian,Tianjin, the fineness modulus is 2.8 in the medium sand,
continuous gradation;
Rubble: Jixian, Tianjin, 5~20mm continuous graded crushed stone
Metakaolin: Inner Mongolia Super KAOPOZZ TMK1100 metakaolin, particle size
1250mesh.
11
Poly carboxylic acid high performance water reducer: Shanxi Huang Teng Chemical
Co.,Ltd produce early strength poly carboxylic acid high performance water reducer.
(2) Test Method
After the concrete is formed, steam-cured with below curing system: stop for 2 hours,
improve temperature ( 20℃ to 80℃) for 2 hours, keep 80℃ for 5 hours, then lower
the temperature, after 2 hours, make the concrete compressive strength test.
(3) Test result and analysis
Table 7 Concrete steam curing test
Poly Compressive
Meta Silica
Cement, Sand, Rubble，k Water, carboxylic Slump strength
No. kaolin, fume,
kg/m 3
kg/m 3
g/m3
kg/m 3
acid , , mm after steam-
kg/m3 kg/m3
kg/m 3
cured ，MPa
1 408 0 0 765 1157 112 7.8 50 69.6
2 367.2 40.8 0 735 1187 112 8.6 45 83.6
3 375.4 0 32.6 735 1187 112 8.9 50 79.5
Note: The temperature of the concrete into the mold is 23℃
Analyse the table 7 test result, after using 10% KAOPOZZTMK1100 metakaolin
replacing cement, the sand ratio of concrete can be lowered in a certain extent. If
slightly increase poly carboxylic acid high performance water reducer, adjust slump
constant to 30-50mm; after using 8% silica fume replacing cement, the sand ratio of
concrete can be lowered in a certain extent djust slump constant to 30-50mm.After
steam-cured, the compressive strength was 69.6MPa; With 10% metakaolin, the
compressive strength was 83.6MPa. With 8% silica fume, the compressive strength
was 79.5MPa. This means to replace cement with metakaolin and silica fume, both
can improve concrete steam curing strength, but 10% KAOPOZZ TMK1100 metakaolin
12
is better than 8% silica fume.
IV. Analysis of the test result
From the above test result with KAOPOZZTM metakaolin, the conclusion is:
1. KAOPOZZTM metakaolin has very high pozzolanic activity, the early and later
activity is higher. If add in mortar and concrete, it’s benefit for improving the early
strength and later strength.
2. Add 10-15% KAOPOZZTM , can improve concrete durability, improve concrete’s
resistance to chloride ion penetration, freezing thawing resistance and prevent
concrete alkali aggregate reaction.
3. With KAOPOZZTM, can improve concrete compressive strength, suitable for the
preparation of steam curing process of concrete, concrete products, such as pipe,
segment, track slab and bridge etc.
4. In concrete, the dry shrinkage of KAOPOZZTM metakaolin is smaller than silica
fume, can reduce the cracking risk of concrete.
13
14
