3D printing concrete:
Fresh Properties and
RheologyM. Sonebi, Queen’s University Belfast, UK
M. Rubio, Queen’s University Belfast, UK
S. Amziane, Polytech-Clermont Ferrand, France
A. Perrot, UBS Lorient, France
Increase of population, need more houses,
infrastructures, etc
World population on Sept 26, 2017 at 19:25 pm GMT 7,570,100,000
World population on Sept 26, 2017 at 19:30 pm GMT7,570,101,000
(+1000)
Conservative estimation of the amount of concrete
produced every year on the planet:
more 15,000,000,000 t
…over 2 ton/inhabitants; and there are good
reasons for this …. is cost (cheaper!)
Conventional Construction of buildings
Labour intensive and inefficient, time of construction, health and
safety insurance, society, ..
Wasteful and Climate Change : emission of CO2 (carbon foot print)
Modern slaves in some countries, Corruption prone (tender, during
construction, market, etc),
High cost
Solutions
• We used robotics now to produce our cars, appliances, mobiles, TV, computers, iphone,
Ipad, iwatch, clothes, shoes, foods, mails, etc
Digital – future with robots buildings
Race to build first 3D-printing building
The race to build the first 3D-printed building is already started.
Would you live in a house that came out of a printer? Would you prefer Concrete, or
Plastic? Biodegradable, or Weather resistant? Canal house or futuristic spider's nest?
The phrase "form follows function" was coined in 1896, just as it became clear that
concrete, glass and steel would free architects to design buildings in completely new ways
that had nothing to do with what came before. What's going to happen to the buildings we
erect with 3D printers?
A future with robots
It seems every week we hear a new doom-
laden prediction about the impact of robots
and other forms of automation on jobs. But
are we looking at this the wrong way - too
inclined to hang on to the world of work as it
is today, too unimaginative about how it
could be transformed for the better by
technology?
The robots, like other tools invented by
humans, can help us or harm us.
But they are not going away.Not all robots would be good to live with
Benefits of 3 D printings
We can enumerate the benefits of 3D printing in construction: “It is always worth reiterating, the main benefits of concrete-3D printing on a large scale are as follows:
1. Higher customisation potential (flexibility in design, and environmental impact)
2. Very low construction waste (Formwork represents 35-60% of the overall cost)
3. Reduced need of more labour (Health and safety)
4. Reduced time of the construction (Cost-effective)
University Loughborough (UK)
(Le et al. 2012)
(Free Construction Research Project – 2010)
First 3D bench
On 16 Feb - 2017
Objectives
The aim of this study is to characterize the effect of the fly
ash, silica fume, the dosage of SP, dosage of fibres, and the
type of viscosity modifying admixtures on the workability, the
rheological behavior and opening time of 3D printing mortar.
Experimental program
Parameter Values
W/CM 0.50
Fly ash 24%
Silica fume 8%
SP (0.55%, 0.28%)
SP – ½ SP
Polypropylene Fibres (6mm) (1.2kg/m3); PP-2PP-3PP
VMAs – Diutan gum(DG) & Nano-clay(nC) (by mass of
CM)
0.05% - 0.10%
Materials
Ordinary Portland cement : Class 42.5 N (BS ENV 197-1 CEMI)
Fly ash – BS EN 450
Silica fume (BS EN 13263-1)
Sand (1.18 mm)
SP - polycarboxylic ether (30% SC, 1.05)
VMAs - diutan gum (Polysaccharide gum), Nano-clay
Polypropylene fibres
Experimental Program
11
Tests
Fresh tests methods
1) Flow table test
Consistency
2) Penetrometer test
Consistency
3) Cylindrical slump flow
Semi-empirical yield stress
Mixes were too stiff to be characterised
by the viscometer
4) Gun test
Extrudability
5) Time gap test
Build up rate of cement based
material
Limit of stiffness for extrusion
Measurements every 15 min
1
2
3
4
Effect of fly ash on fresh properties of 3D printing
NO FA
FA35
36
37
38
39
40
230
240
250
260
270
280
290
NO FA SP PP SP PP
Pen
etr
om
ete
r (m
m)
Slu
mp
flo
w (m
m)
Slump f low Penetrometer
With FA
Effect of Silica fume on fresh properties of 3D printing
NO SF
SF20
25
30
35
40
0
50
100
150
200
250
300
SP PP SF SP PP
SP 2 PP
SF SP 2PP
Pe
ne
tro
mete
r (m
m)
Slu
mp
flo
w
(mm
)
Slump flow Penetrometer
S.FlowS.Flow
Pntr Pntr
Effect of SF on fresh properties of 3D printing
NO SF
SF0
200
400
600
800
1000
0
50
100
150
200
250
300
SP PP SF SP PP
SP 2 PP
SF SP 2PP
Es
tim
ate
d y
ield
str
es
s (
Pa
)
Slu
mp
flo
w
(mm
)
Slump flow Estimated yield stress
Est. z
Effect of PP fibre on fresh properties of 3D printing
10
20
30
40
50
210
220
230
240
250
260
SP PP SP 2 PP SP 3PP
Pe
ne
tro
mete
r (m
m)
Slu
mp
flo
w (m
m)
Slump flow Penetrometer
S.Flow
Pntr
PP
2PP
3PP
1PP
2PP
3PP
Effect of reduction of SP on fresh properties of 3D printing
15
20
25
30
35
40
0
50
100
150
200
250
300
SP PP 1/2SP PP SP 2 PP 1/2SP 2PP SP 3PP 1/2 SP 3 PP
Pe
ne
tro
me
ter
(mm
)
Slu
mp
flo
w (
mm
)
Slump flow Penetrometer
SP
PP 2PP 3PP
Effect of reduction of SP on fresh properties of 3D printing
0
200
400
600
800
1000
1200
0
50
100
150
200
250
300
SP PP 1/2SP PP SP 2 PP 1/2SP 2PP SP 3PP 1/2 SP 3 PP
Es
tma
ted
yie
ld s
tre
ss
(P
a)
Slu
mp
flo
w (
mm
)
Slump flow Estimated yield stress
PP 2PP 3PP
τ
τ
Effect of type of VMA on fresh properties of 3D printing
10
20
30
40
50
0
50
100
150
200
250
300
SP PP VMA1 SP PP
VMA2 SP PP
Pe
ne
tro
me
ter
(mm
)
Slu
mp
flo
w (
mm
)
Slump flow Penetrometer
VMA1-DG VMA2-nC
0
200
400
600
800
1000
0
50
100
150
200
250
300
SP PP VMA1 SP PP
VMA2 SP PP
Es
tim
ate
d y
ield
str
es
s (
Pa
)
Slu
mp
flo
w (
mm
)
Slump flow Estimated yield stress
Effect of type of VMA on fresh properties of 3D printing
VMA1-DG VMA2-nC
Correlation between slump flow vs.
penetration of 3D printing
R² = 0.86
100
120
140
160
180
200
220
240
260
280
17 22 27 32 37 42
Slu
mp
Flo
w (
mm
)
Penetration (mm)
R² = 0.89
140
150
160
170
180
190
200
19 24 29 34
Slu
mp
Flo
w (
mm
)
Penetration (mm)
(a) different PP and SP (b) with and without SF
Correlation between yield stress flow vs.
penetration of 3D printing
(a) different PP and SP (b) with and without SF
R² = 0.88
100
120
140
160
180
200
220
240
260
15 215 415 615 815 1015 1215
Slu
mp
Flo
w (
mm
)
Yield stress (Pa)
R² = 0.81
100
110
120
130
140
150
160
170
180
190
200
600 700 800 900 1000 1100
Slum
p Fl
ow
(mm
)
Yield stress (Pa)
Opening time – Effect of FA & SF on 3D printing
(a) FA (b) SF
Opening time – Effect of PP fibre & SP on 3D
printing
(a) PP fibre (b) SP
Opening time – Effect of type of VMA on 3D printing
DG
nC
Printability
0
200
400
600
800
1000
1200
1400
0 20 40 60 80 100 120 140 160
Es
tim
ate
d y
ield
str
ess
(P
a)
Time (min)
risk of none printability
Mix too fluid and risk of drainage
risk of none printability
surface defect, risk of drainage and
reduce of the rate due to the
stiffness of the mix
"Printable" mixes
Cold joints
If layers of concrete have
limited intermixing and if the
critical resting time value has
been exceeded, cold joints are
susceptible to appear.
Coloured layers-intermixing
3 D printing layers
2 printed layers 4 printed layers
13 mm
13 mm
11 mm
10 mm
13 mm
13 mm
Recommendations of 3D printing mortar
155 mm < spread diameter < 235 mm
open time <100 min
600 < τ0 <1050 Pa
20 < Penetration < 39 mm
3D polar bear at Copenhagen Airport – Aug. 2016
Visual illusion
(3D vs. 2D)
Thank you for your attention
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