ji GPey'

review of some of the properties of

Geoseal MQ-5 and silicate-Hardener
600B grouts ss
0
by Murat Mollamahmutoglu, Civil engineering
department, Gazi University, Ankara, Turkey; 4
and GS Littlejohn, Civil engineering m
18-
department, University of Bradford, UK.

Synopsis
The purpose of this paper is to provide data on some physico-
chemical characteristics such as initial viscosity, viscosity-time 20 40 60 80 100 120
Gel time (minutes)
development, syneresis and gel time for Geoseal MQ-5 and
silicate-Hardener 600B chemical grouts. The results of Figure 1. The effect of Geoseal MQ-5 solution
permeation tests are also described with particular reference to
groutability of Leighton Buzzard Sand and Thames Ballast
Sand using the two chemical grout systems. Unconfined % 15 solids solution
compressive strengths of the grouted sands are provided where
permeation has been achieved.

Characteristics of Geoseal MQ-5 grout

Geoseal MQ-5 is a water soluble tannin/formaldehyde resin
powder. The powder is blended with catalytic agents thus
eliminating the need for weighing and adding components
under difficult site conditions and only the addition of water is
necessary. Providing the pack remains unopened and is stored
in dry conditions, the resin will remain stable for at least one
year at 21'C'. It is dissolved in water before use and is generally iS 3'0 3'S 4'0 4'S S'0 SS
used at mix concentrations in the range of 13-22% by weight. Temperature ('C)
The resin powder is slowly added to the required amount of
water and stirred vigorously to ensure the complete dissolution Figure 2. Variation of gel time with temperature at
of the powder in water. The period of mixing in this research different solution concentration of Geoseal MQ-5.
programme was three minutes, employing a soil laboratory
mixer. be disposed of as normal solid industrial waste because Geoseal
The grout solution is alkaline and has a PH value of MQ-5 is based on a naturally occurring vegetable tannin which
approximately 9. The grout has a marked staining effect and is slowly biodegradable.
any splashes on the skin may cause discomfort due to the A rotational viscometer known as a Rotovisco or Haake
mildly alkaline nature of the grout. It is strongly recommended viscometer was used to determine the viscosities of Geoseal
therefore that gloves and goggles are worn by all personnel MQ-5 grouts. The sensor system and shear rate were MVl
involved in mixing operations. Additional skin protection may rotor and 54.3 (Vs) respectively.
also be provided by either water repellent barrier creams or The viscosity-time development curves of Geoseal MQ-5 for
petroleum jelly, eg Vaseline. Geoseal MQ-5
contains anti-dust additives but in wind swept or 1000
15 % solids solution
draughty environment air born dust may become Imtial viscosity: 22 cP
a nuisance and under such conditions, the use of
light dust mask is advised. 17 % solids solution
Initial vismsity: 2.4 cP
The gel time, the measured time interval
between the mixing of a grout system and the o 600 19 % solids solution
formation of a gel', of the grout is dependent Initial vismsity: 3.1cP
upon the solution concentrahon as well as
ambient temperature shown in Figures 1 and
The set gel which is the condition where a liquid
2..5 400
22 % solids solution
Initial viscosity: 4.2 cP

grout begins to exhibit measurable shear strength Tcsnpcrature: 22 'C

maintains a rubbery consistency in water. On the
other hand when the gel is exposed to air, eg
20'C the gel desiccates and decomposes with 0- ——
time. Any surplus grout should be poured into 0 20 40 60 &0 100 120
Time (minutes)
drums or other suitable containers and allowed to
44 gel. The set grout is insoluble in water and may Figure 3. Vi scosity-time relation of Geoseal MQ-5.

GROUND ENGINEERING ~ SEPTEMBER ~ 1995

 4.5
0.22
15% solids solstion
Temperature: 22 C 0.2 17%soMs solsdan
19%solds solution
0.18
22% salds solntian
~~ 0.16—
.I"
0.14—
~ 0.12-
0.1—

2 0.08
20 40 60 80
14 16 18 20 22 24 1une (days)
Solution concentration (%)

Figure 4. Effect of solution concentration of Geoseal Figure 6. Synersis of Geoseal MQ-5 grout geis versus
MQ-5 on the initial viscosity. time.
15%, 17%, 19% and 22% solution concentrations are shown in neutralisation. Thus, a dilute sodium silicate solution mixed
Figure 3. For each grout formulation viscosity increases slowly with certain acids or acid salts will form a gel after a time
with time after mixing, and initial viscosity increases with interval related to chemical concentrations and as well as the
increase in solution concentration (see Figure 4). Figure 5 specific kinetics of the alkali neutral isation reaction'.
shows that the viscosity of Geoseal MQ-5 grout is also Sodium silicate used in this research is grade M75 and
temperature dependent. manufactured by ICI. M75 silicate solution is clear or slightly
Geoseal MQ-5 suffers Rom syneneris as some other cloudy aqueous, odourless and non-toxic. It has a silica alkali
chemical grouts do. Syneresis is the exudation of liquid I'rom a ratio (molecular ratio) of 3 with a specific gravity of 1.375 and
set gel which is not stressed, due to the tightening of the grout viscosity of 100cP at 20'C.
material structure and quoted as the &action of volume loss per Hardener 600B is an open-chain compound diacid ester. It
unit volume (Av/v). Figure 6 illustrates the amount of syneresis is manufactured by Rhone Poulenc, France. It has very weak
for different solution concentrations at various time intervals. smell, low odour, dark brown colour, low fusion, high boiling
As can be seen Rom the figure the amount of syneresis point (220'C), a density of 1.09 and viscosity of 5cP at
increases with time and the grout nearly stabilises after 80 days. 20'C'.
In addition, increase in solution concentration of Geoseal Hardener 600B, when dispersed in a solution of sodium
MQ-5 decreases the magnitude of syneresis. silicate, neutralises the alkali in the sodium silicate and forms a
silica The gel softens in water and partially dissolves but
Characteristics of silicate-Hardener 600B gains gel. strength and becomes hard with time. As the gel dries out
grout in open air it shrinks and becomes very brittle material.
Sodium silicate, n-SiO, Na,O, is commercially available as an The gel time can be altered by varying the concentration of
aqueous solution. The silica/alkali ratio, n, is important in that the various components of the grout mix, i.e. the sodium
ranges of 3 to 4 yield gels with adhesive properties, particularly silicate, the water of dilution and Hardener 600B and the
suitable for grouting (beyond a ratio of 4, the silicate becomes ambient temperature (see Figures 7, 8, 9).
unstable). Silica is weak acid, and sodium silicate is therefore The viscosity-time development curves for grout mixes with
basic. Hydrated silica will be precipitated as a gel by 40%, 60%, and 80% silicate content plus 7% Hardener 600B
content are shown in Figure 10. As shown in the figure,
the viscosity increases with time Rom the start of mixing
until the grout gels for all grout formulations. The
viscosity measuring system and shear rate were the same

'~atop rstnre:
,
~
22%soridssointian as those of Geoseal MQ-5 grout. Figure 11 shows that
increase in ambient temperature increases the reaction
and so reduces the set time. It is also seen in the figure
Temperstnre: Isac that the data for the early part of the test do not show a
lower viscosity for the higher temperature tests. It is due
Ternperstna:: I«ye to the fact that the hardener and silicate were not
conditioned to the appropriate test temperature prior to
Inlxlllg.
The initial viscosity increases with the increase in
Hardener 600B and silicate contents as depicted in
0 50 100 150 200
Time (minutes)
Figure 12. Silicate-Hardener 600B grouts too are
subjected to syneresis, the amount of which is negligible
Figure 5. ESect of temperature on the viscos ity-time relation of for 70% and 80% silicate contents and the syneresis
Geoseal MQ-5. ceases after three days. However, the amount of syneresis 45
GROUND ENGINEERING 'EPTEMBER '995
 10

7 % Hardener 600B
80—

50—

60
@0

c - c 20—
I

DC
4 10—
20 30 40 50 60 70 80 90 100
Gel time (minutes)
40%silicate 50%silicate 60%silicate
0 0 0
0 20 40 60 80 100 0 20 40 60 80 100
70 % silicate 80 % silicate (cC)
Gel time (minutes) Temperature

Figure 7. Effect of silicate content on Figure S. Effect of Hardener 600B Figure 9. The effect of temperature on
gel time (after Mollamahmutoglu, content on gel time at 20 C (afte gel time of silicate-Hardener 600B
1992). Moltcc~ccbcciutoglu, 1992). grouts (affer Motla~~miutoglu, 1992).

is high at low silicate contents and increases with time (see carried out to facilitate sand deposition. The gravel filter was
Figure 13). put at the top of the sand for the same purpose as mentioned
earlier, and the top cap was screwed onto the mould. The
Strength tests specimen was now ready to be connected to outlet and grout
Two different sands used in this experimental study are chamber to receive grout. After mixing the pro-measured
Leighton Buzzard and Thames Ballast. The particle size quantities of grout components the grout solution was poured
distribution-of both sand is shown in Figure 14. into the pressure chamber and the injection commenced. The
Both sand samples were injected with various solution detailed illustration of injection system used can be seen in
concentrations of Geoseal MQ-5 and silicate-Hardener 600B. Figure 15. The parameters shown below were kept constant
Sand specimens were prepared using steel moulds, 38mm in throughout the experimental study'.
diameter and 300mm in length, which were split into two
pieces longitudinally. After assembling the split mould it was Relative density of sands: 70%
clamped between the top and bottom plates and filled with Rate of grout advance: 0.013-0.017m/s
water. Fine gravel was placed at the bottom of the mould in Volume of excess grout: 120% of void ratio
order to stop sand blocking up the connecting lines and to Sample preparation: submerged condition
distribute grout uniformly to the bottom of the sand specimen.
The required amount of sand, around 480g, was poured into a While the grout injection was in progress, graduated cylinders
narrow-necked volumetric fiask through a funnel and the flask were used to collect pore water as well as excess grout solution.
was then topped up with water. The sand prepared in this way Having ensured that the correct quantity of excess grout had
was tipped into the mould through the opening in the top plate, been vented the injection procedure was terminated. The
and while tipping, light tamping of the sides of the mould was grouting cells were left standing for curing. Approximately 18
40
Temperature: 20 C
'
35 ~ Ocl ticcc
40%+7%+53% SiTicste + Hardener 600B + Water
Temperature: 10 C
30
Temperature: 7 C
o„, 25

> 15

10 /

0 70
0 10 20 30 40 50 60
Time (minutes)
0 20 40 60 100
SiTicate content: 40 % Hardener content: 7% Water content: 53 %
Time (minutes)

Figure 10. Viscosity-time behaviour of silicate-Hardener Figure 11.Effect of temperature on the viscosity-time
46 600B grouts. behaviour of silicate-Hardener 600B grout.

GROUND ENGINEERING 'EPTEMBER ~ 1995

 Hardener 600B content (%)
5 6 7 8 9 10
144

12

10

0.7
Sgicste couteau 20 %

0.6- SBIcste content: 30 %

Silicate couteau 40 %
05 Sgicste couteau 60 %

I 0.4 Silicate content 70%

Silicate couteau 80 %
o 03 Hardener content: 7 %

Temperature: 20 oc
0 0.1-
35 40 45 50 55 60 65 70 75
Sgicate content (%)
Figure 12. Effect of silicate content 0 20 40 60 &0
and Hardener 600B content on the Time (days)
initial velocity. Figure 13. Synersis of silicate-Hardener 600B grouts with thne.
to 20 hours after injection the grouting cells were dismantled
and samples were cut to the required length (38mm in
diameter and 76mm in length). Since three samples can be
obtained from each grouting mould they were identified with
appropriate marks to reference their position in the grouting
A
mould during the injection and the grout solution with which
they were injected'. oI,60-
The grouting pressure for Leighton Buzzard sand was very
low (2-4psi) in comparison with the Thames Ballast sand
(40-50psi) at 15% solution concentration of Geoseal MQ-5
due to the finer grained nature of the Thames Ballast sand.
j'-
Only the 15% MQ-5 solution permeated the Thames Ballast
sand satisfactorily. The 17% atld 19% solutions failed to
permeate more than '/, of the total height of sand column
(100mm out of 300mm) at a high grouting pressure of 40psi.
The Thames Ballast sand was also injected with 40% silicate 5.05 0.1 02 0.5 1 2 5
Partic)e size (mm)
plus 7% Hardener 600B grout but with no success (permeated
about 40mm out of 300mm sand column). Fine Medium Coarse Fine
Unconfined compression tests were conducted at a shear rate
I

Sand
I I

G ~i I

of 1.52mm/s on the Geoseal MQ-5 and silicate-Hardener 600B

permeated sands of one day cured wet samples and the results Figure 14. Particle size distribution curves for sand
are summarised in Tables 1 and 2. component of Thames Ballast (1) and Leighton Buzzard
sand.

Unconlined compressive strength UrconSned compressive strenglh

Geoseal MQ-5
mbr concentration (kPa) Type of sand (kPa)
Type of sand
Bsicate: Water: Ester Top Middle Bosom
(%) Top Middle Bottom
40:53:7 175 181 187
15 teighton Buzzard 120
343 342
17 Lsigtaon Buzzard 180
412 420

18 taighton Buzzard 210 188 188 1147 1183 1131

15 80:13:7 Leighton Buzzard 1111 1305, 1283

~ Grouted sample posiaon in the grout mould

Table1. Unconfined compression test results for Geoseal Table 2. Unconfined compression test results for silicate-
MQ-5 grouted sands. Hardener 600-B ester grouted Leighton Buzzard sand. 47
GROUND ENGINEERING ~ SEPTEMBER ~ 1995
 70-80% of the gel time for each grout mix.
0 The viscosity of the grouts for a period of 15 minutes seems
not to be increased by increase in ambient temperature. It is on
"valse 'ltgts l tires" 'I'lllll account of the fact that the hardener and silicate were not
conditioned to the test temperature before mixing.
20 . Furthermore, increase in the grout temperature increases the

1
r
~~- 8
v~
t

7
v

~~J
chemical reaction and so reduces the set time.
9 The initial viscosity increases linearly with the increase in
Hardener 600B. The initial viscosity for a formulation with 9%
Hardener 600B content is about 1.3 greater than the
1 Moald 6 Air regalater 11 Gravel alter formulation with 7% Hardener 600B content. Grout
2 Gradaaaxl glass rabe 12 assess groat
3 Valve 13 Groat
formulations with higher silicate content give rise to higher
8 Valve
4 Plessme ga age 14 Warm mater sari groat increase in the initial viscosity. For example, 2.8cP at 40%,
3 Premare cbambef lp 8 d 15 Presmrised air
7.5cP at 60%, 12cP at 70% silicate contents with the 7%
Hardener 600B content.
Figure 15. Illustration of grout injection system (after 0 Silicate-Hardener 600B grouts sufFer &om syneresis. The
Mollamahmutoglu, 1992). amount of syneresis increases with time for 30%, 40% and
60% silicate contents but stabilises after three days for 70% and
Conclusions —Geoseal MQ-5 grout 80% silicate contents and at high silicate contents such as 70%
0 Increase in the solution concentration of Geoseal MQ-5 by and 80% the amount is much less compared to those of low
3% reduces the gel time &om 50 to 30 minutes. Variation of silicate contents of 30%, 40% and 60%. For instance, it is 0.25
temperature has initially a considerable efFect on the gel time of at three days for 40% silicate content while it is 0.02 at three
Geoseal MQ-5 grouts, which is less at the high solution days for 70% silicate content.
concentrations. For example, an increase about 10'C in The permeation of Leighton Buzzard sand was successful
temperature halves the gel time of 15% solution concentration with the silicate-Hardener 600B grout of 40% silicate content,
but has not that much efFect on the 22% solution 53% distilled water and 7% Hardener 600B. However, the
concentration. same grout formulation failed to permeate the Thames Ballast
8 Viscosity of Geoseal MQ-5 grout except 22% solid solution sand with Dip of 0.15. Increase in silicate content brings about
does not vary considerably until the onset of gelation ie the high unconfined compressire strength of
time when there is a sudden increase in viscosity. silicate-Hardener 600B grouted Leighton Buzzard sand. For
0 Up to 60 minutes, except 22% solid solution, viscosities of instance, 187kPa at 40% and 1293kPa at 80% silicate
Geoseal MQ-5 grouts are not affected by increase in ambient contents.
temperature until the grout temperature gets to that of ambient 9 As can be seen &om the Tables 1 and 2, the data suggest that
temperature. But, the gel time is shortened owning to the there is no trend of strength with position in the sample.
increased rate of reaction resulted &om'the rise in grout
temperature. The same trend is observed regarding the silicate- References
Hardener 600B grouts. 1. Borden. 'Geoseal MQ-5 technical information brochure', England, 1981, 3p.
2. Comminee on grouting of the Geotechnical Engineering Division. Preliminary
O The initial viscosity increases with the increase in solution Glossary of terms relating to grouting, ASCE Journal of the Geotechnical
concentration of Geeseal MQ-5 grout. For instance, while it is Engineering Division, July 1980, pp803-815.
2.1cP for 15% solid solution it is 3.1cP for 19% solid solution. 3. Karol RH. 'Chemical grouts and their properties'. Proceedings of the
0 Geoseal MQ-5 grouts too are subject to syneresis, the Conference on Grouting in Geotechnical Engineering, New Orleans, 1982,
pp359-377.
amount of which increases with time but tend to stabilise after 4. Mollamahmutoglu, M. 'Creep behaviour of silicate-ester grouted sand'. PhD
80 days. In addition, the higher the solution concentration the thesis, University of Bradford, Bradford, UK, 1992, pp251.
less the syneresis is, eg 0.11 at 15%, 0.09 at 22% solution 5. Rhone Progil. 'Hardener 600 series, Rhone Progil technical brochure', C10B,
concentrations at seven days. France, 1975, 49p.
I Even though 17% solution concentration of Geoseal MQ-5
grouts failed to permeate more than '/, of the total height
(100mm of 300mm sand column) of sand column at a high
grouting pressure of 40psi the 15% solution concentration
permeated the Thames Ballast sand producing an unconfined
compressive strength of around 90kPa.

Conclusions —Silicate-Hardener 600B

grout
0 The gel time increases linearly with the increase in silicate
content whereas it decreases linearly with the increase in
Hardener 600B. Increase in temperature by 10'C halves the gel
time initially but the efFect drops off suddenly after 40'C.
6 Viscosity of silicate-Hardener 600B grout increases with
time &om the start of mixing until the onset of gelation. The
48 onset of gelation for silicate-Hardener 600B grout is about

GROUND ENGINEERING ~ SEPTEMBER ~ 1995