Popular in Engineering

Electronic Engineering

Control of a Wheelchair-Mounted Robotic Arm System

University of South Florida Redwan Alqasemi

Engineering

Spatiotemporal evaporating droplet dynamics on fomites enhances long term bacterial pathogenesis

Indian Institute of Science Saptarshi Basu

Chemistry

Polyfluorene-Wrapped Carbon Nanotubes Decorated with Photocleavable Side-Chains

McMaster University Alex Adronov

Electronic Engineering

A Trusted and Privacy-Preserving Internet of Mobile Energy

Queensland University of Technology

Engineering

Water Security: Why We Need Global Solutions

Cardiff University

Engineering

Decision-Making Principles for Better Software Design Decisions

Swinburne University of Technology

Civil Engineering

Adaptive Traffic Signal Control With Deep Reinforcement Learning and High Dimensional Sensory Inputs

University of Toronto

Suitability of excavated London clay as a supplementary cementitious material

View more insights in Professional - Engineering - Civil Engineering

View more figures from ARUP

View the page of Fragkoulis Kanavaris

Read the Study

Next in Civil Engineering

Subjective vs. objective assessment of the economic impacts of light rail transit

Liton Kamruzzaman | Monash University

Optimum numbering and sizing of infiltration-based water sensitive urban design technologies in South Australia

Faisal Ahammed | University of South Australia

Fragkoulis Kanavaris discusses the potential of producing supplementary cementitious materials (SCMs) using London Clay excavated from construction activities of the High Speed 2 rail project. A trade-off between enhancing reactivity versus decomposition of impurities (e.g., pyrite, carbonates) present in different London Clay samples was considered in selecting the calcination temperature.

Image courtesy of interviewee. January 25, 2024

Log-in or Sign-up to Faculti
Currently viewing this subject insight as a guest. You have insight(s) remaining for this month. Login to view 8000+ figures on the platform.

Generating Workspace...

Export as PDF

The speaker discusses a major infrastructure project in London, focusing on the extensive excavation required due to tunneling that generates significant waste consisting mainly of London clay. Traditionally, this clay has been removed and used as landfill, leading to high costs and carbon emissions. The goal of the study was to explore innovative uses for this excavated London clay, particularly as a replacement for Portland cement in concrete, thereby reducing waste and embodied carbon.

The research involved detailed characterization of London clay and investigating its potential for transformation through calcination (heating) to create a reactive material usable in concrete. Despite the clay's low carbonate content, which poses a challenge for its reactivity, the study found that good quality concrete could be produced with 50-70% replacement of Portland cement using London clay, achieving strengths of 40-60 megapascals.

The most significant conclusion of the research indicates that waste clays, which are often discarded, can be effectively repurposed as supplementary cementitious materials, paving the way for further exploration of less reactive materials in concrete production. This video video offers a sustainable solution to using excavation waste while maintaining concrete quality.

Language:

Export as PDF

X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:90000

1
00:00:00.265 --> 00:00:04.345
The motivation behind it, behind this work,

2
00:00:05.125 --> 00:00:06.465
was the fact that we were working

3
00:00:06.645 --> 00:00:08.465
and we have been still working,

4
00:00:08.565 --> 00:00:11.985
on a major infrastructure project development in, in the UK

5
00:00:12.045 --> 00:00:14.145
and specifically in, in London.

6
00:00:14.525 --> 00:00:16.865
And that's part of that major infrastructure project.

7
00:00:17.235 --> 00:00:20.345
We're talking about several kilometers of, of,

8
00:00:20.495 --> 00:00:23.585
high speed railway lines and several kilometers of tunnels.

9
00:00:24.085 --> 00:00:26.985
Um, which as part of the construction

10
00:00:27.045 --> 00:00:30.265
of these infrastructure assets, there is a lot,

11
00:00:30.665 --> 00:00:34.225
a vast majority of excavated material that is going

12
00:00:34.225 --> 00:00:37.025
to be generated because we have tunnel boring machines,

13
00:00:37.025 --> 00:00:38.945
for example, operating as part of,

14
00:00:39.005 --> 00:00:40.905
of the tunneling construction process.

15
00:00:41.405 --> 00:00:44.105
And that generates a significant volume of,

16
00:00:44.245 --> 00:00:45.505
of excavation waste.

17
00:00:46.085 --> 00:00:47.505
And that excavation waste

18
00:00:47.895 --> 00:00:49.985
because of the, the location

19
00:00:49.985 --> 00:00:53.785
that we are situated in London is predominantly London clay.

20
00:00:54.245 --> 00:00:58.275
And that brings us to the, question

21
00:00:58.455 --> 00:01:00.955
or answering the question of what London Clay is.

22
00:01:01.055 --> 00:01:03.955
And London Clay is a marine geological formation.

23
00:01:04.305 --> 00:01:06.475
Essentially, it's a soil, it's a clay.

24
00:01:06.945 --> 00:01:10.435
That whole lot of London is sitting on that clay.

25
00:01:10.855 --> 00:01:13.155
So nobody knows where bedrock is in London.

26
00:01:13.295 --> 00:01:15.795
And of course I'm saying this with,

27
00:01:16.095 --> 00:01:17.395
joking matter.

28
00:01:17.815 --> 00:01:20.795
Uh, but there's abundant

29
00:01:21.385 --> 00:01:25.275
clay present in London that normally during these kind

30
00:01:25.275 --> 00:01:26.555
of excavation operations,

31
00:01:27.065 --> 00:01:29.195
this clay is being extracted from the ground,

32
00:01:29.195 --> 00:01:31.035
removed from the ground, and,

33
00:01:31.165 --> 00:01:33.515
repurposed somewhere else as landfill.

34
00:01:33.775 --> 00:01:37.275
And we know that this operation of repurposing the clay,

35
00:01:37.365 --> 00:01:38.875
excavating the clay from London

36
00:01:39.415 --> 00:01:41.155
for infrastructure development

37
00:01:41.535 --> 00:01:45.235
and repurposing it somewhere else as landfill is associated

38
00:01:45.305 --> 00:01:47.655
with significant embodied carbon

39
00:01:47.995 --> 00:01:49.615
and significant, significant cost.

40
00:01:50.235 --> 00:01:53.935
Um, so what we are doing in, in this as part of this study,

41
00:01:54.475 --> 00:01:57.295
we thought, okay, we need to think out of the box

42
00:01:57.475 --> 00:02:01.695
and try to find ways to, repurpose that excavated clay,

43
00:02:01.755 --> 00:02:03.735
the excavation waste,

44
00:02:03.955 --> 00:02:06.695
in high value application rather than landfill it

45
00:02:06.695 --> 00:02:08.615
and transporting kilometers away from London.

46
00:02:08.915 --> 00:02:12.895
The focus of that study was London Clay itself.

47
00:02:13.895 --> 00:02:16.955
So we first thought, okay, what can we do with London Clay?

48
00:02:17.555 --> 00:02:19.855
London Clay is a, a clay.

49
00:02:20.635 --> 00:02:23.415
So that takes us a step back to consider

50
00:02:23.645 --> 00:02:24.975
what can we do with clays?

51
00:02:24.975 --> 00:02:26.335
And very important,

52
00:02:27.495 --> 00:02:30.855
research accomplishment over the past years, in, in,

53
00:02:30.875 --> 00:02:32.215
in the material science field

54
00:02:32.215 --> 00:02:35.575
or construction material science field was the utilization

55
00:02:35.595 --> 00:02:37.815
of clays for the replacement

56
00:02:37.815 --> 00:02:39.975
of Portland's men concrete in order

57
00:02:40.035 --> 00:02:41.895
to reduce concrete symboled carbon.

58
00:02:42.875 --> 00:02:45.015
So what we did in this case, we thought, okay,

59
00:02:45.015 --> 00:02:47.735
we can use other clays which are suitable

60
00:02:47.835 --> 00:02:49.855
for replacing Portland's main concrete.

61
00:02:50.395 --> 00:02:54.135
Why should we not try and use London clay for that purpose?

62
00:02:54.285 --> 00:02:57.615
That was never tried before, never tried before.

63
00:02:58.075 --> 00:03:01.165
Um, so it was a bit of uncharted territory for us.

64
00:03:02.265 --> 00:03:05.685
And, we took, a very detailed approach

65
00:03:05.785 --> 00:03:08.325
to towards characterization of that material.

66
00:03:08.865 --> 00:03:11.805
Uh, so we started with collaboration with,

67
00:03:11.805 --> 00:03:14.445
different reputable, academic institutions

68
00:03:14.625 --> 00:03:18.605
and, also, consultancies.

69
00:03:19.065 --> 00:03:21.405
And, we derived a detailed plan,

70
00:03:21.575 --> 00:03:23.565
which involves material characterization,

71
00:03:23.855 --> 00:03:25.965
micro structural material characterization

72
00:03:26.025 --> 00:03:27.445
of the raw clay itself.

73
00:03:27.945 --> 00:03:31.725
And then we investigated methodologies to convert that clay

74
00:03:32.105 --> 00:03:33.925
to a usable material in concrete.

75
00:03:34.185 --> 00:03:37.165
And the way to do this is to heat up the clay

76
00:03:37.705 --> 00:03:40.405
or cal signate as we call it, in scientific terms.

77
00:03:41.265 --> 00:03:44.365
And, that material converts itself

78
00:03:44.365 --> 00:03:48.485
through calcination from, an inert material

79
00:03:48.785 --> 00:03:50.965
to a reactive material for using concrete.

80
00:03:51.385 --> 00:03:54.365
So we did this study of trying to identify

81
00:03:54.705 --> 00:03:59.045
or determine which are the suitable temperature ranges

82
00:03:59.225 --> 00:04:03.145
or, particle size distributions, grinding,

83
00:04:03.325 --> 00:04:06.985
and so on, which are optimum for converting the raw clay.

84
00:04:07.165 --> 00:04:10.585
The as excavated clay from the infrastructure construction

85
00:04:10.585 --> 00:04:12.745
works to a usable material

86
00:04:12.845 --> 00:04:15.785
and concrete with, some requirements

87
00:04:15.845 --> 00:04:17.145
for for performance.

88
00:04:17.445 --> 00:04:20.665
So at first when we started this investigation on the

89
00:04:21.025 --> 00:04:23.625
reactivity of lung and clay, I think it's worth mentioning

90
00:04:23.625 --> 00:04:25.785
that, a metric

91
00:04:25.885 --> 00:04:30.065
or a criterion for describing the reactivity of clays.

92
00:04:30.065 --> 00:04:32.265
And there's suitability for use as,

93
00:04:33.145 --> 00:04:36.305
Portland cement replacement in concrete is the carbonite

94
00:04:36.305 --> 00:04:38.825
content, which is a mineralogical,

95
00:04:38.825 --> 00:04:40.305
phase within, within clays.

96
00:04:40.645 --> 00:04:43.865
Uh, so carbonite is quite key in, in,

97
00:04:43.865 --> 00:04:45.265
in its presence in clays

98
00:04:45.265 --> 00:04:48.585
because it improves the reactivity of these clays.

99
00:04:49.415 --> 00:04:52.275
So the material characterization showed

100
00:04:52.305 --> 00:04:56.835
that London clays are low in carbonate content, let's say

101
00:04:56.835 --> 00:04:57.835
below 30%.

102
00:04:58.535 --> 00:05:02.675
And that could be somewhat problematic for achieving,

103
00:05:02.895 --> 00:05:04.795
for producing a very good, good quality

104
00:05:05.375 --> 00:05:08.475
cal sign clay material for using s for using instead

105
00:05:08.475 --> 00:05:09.835
of portal cementing concrete.

106
00:05:10.955 --> 00:05:14.615
Uh, but what we found through our trials

107
00:05:15.155 --> 00:05:18.255
and concrete development activities was

108
00:05:18.255 --> 00:05:21.895
that we could produce, good quality concrete

109
00:05:22.115 --> 00:05:25.895
by good quality, I mean, 40 to six megapascal strengths

110
00:05:25.915 --> 00:05:26.935
of, of concrete.

111
00:05:26.955 --> 00:05:28.815
And this is been considered

112
00:05:29.035 --> 00:05:31.815
as a relatively good quality concrete in, in the world

113
00:05:31.815 --> 00:05:35.655
of civil engineering, with, 50%

114
00:05:35.715 --> 00:05:38.375
to 70% replacement of Portland cement

115
00:05:38.375 --> 00:05:39.415
with, with London clay.

116
00:05:39.715 --> 00:05:42.255
So that was extremely encouraging with respect

117
00:05:42.255 --> 00:05:45.795
to the suitability of using this excavation waste

118
00:05:46.455 --> 00:05:50.595
as a low cost, low carbon cement replacement in concrete.

119
00:05:50.955 --> 00:05:52.755
I think one of the most important conclusions,

120
00:05:52.935 --> 00:05:55.155
and at least the one that makes me feel the most excited

121
00:05:55.495 --> 00:05:56.555
is that we can

122
00:05:57.185 --> 00:06:01.365
Use, waste clays which are not

123
00:06:01.385 --> 00:06:03.005
so rich in called an A content.

124
00:06:03.385 --> 00:06:05.805
So waste clays, which would, nobody wants

125
00:06:05.825 --> 00:06:07.485
to use them essentially.

126
00:06:07.905 --> 00:06:11.285
Uh, we convert them in a usable supplementary cement tissue

127
00:06:11.525 --> 00:06:12.765
material for using concrete.

128
00:06:12.945 --> 00:06:15.725
And this is really, really a research breakthrough

129
00:06:15.725 --> 00:06:18.205
because over the past decade

130
00:06:18.385 --> 00:06:21.845
or even 15 years, we have seen several studies

131
00:06:22.195 --> 00:06:25.085
that are focusing on quite reactive clay.

132
00:06:25.625 --> 00:06:29.415
But I think our study really paved the way forward

133
00:06:29.915 --> 00:06:34.055
for looking into less reactive materials,

134
00:06:34.685 --> 00:06:36.135
more excavation wastes

135
00:06:36.555 --> 00:06:38.695
and their utilization in the

136
00:06:38.695 --> 00:06:40.055
production of structural concrete.

137
00:06:40.395 --> 00:06:43.015
So I think that this is the most important conclusion,

138
00:06:43.395 --> 00:06:46.935
and we can go down to more details in the conclusions of,

139
00:06:47.275 --> 00:06:48.895
the reactivity of material

140
00:06:49.475 --> 00:06:51.975
or the production of, of concrete strength.

141
00:06:52.235 --> 00:06:55.055
But as a key takeaway, I would like to say

142
00:06:55.405 --> 00:07:00.135
that we can produce good quality concrete, so up to,

143
00:07:00.275 --> 00:07:04.255
40 or six megapascal strengths on a consistent manner,

144
00:07:05.075 --> 00:07:07.735
achieving good radiology,

145
00:07:07.985 --> 00:07:10.855
using this excavation waste, material.

Repurposing London Clay in Infrastructure Projects

00:00:00 - The motivation behind it, behind this work, was the fact that we were working and we have been still working, on a major infrastructure project development in, in the UK and specifically in, in London. And that's part of that major infrastructure project. We're talking about several kilometers of, of, high speed railway lines and several kilometers of tunnels. which as part of the construction of these infrastructure assets, there is a lot,
00:00:34 - to be generated because we have tunnel boring machines, for example, operating as part of, of the tunneling construction process. And that generates a significant volume of, of excavation waste. And that excavation waste because of the, the location that we are situated in London is predominantly London clay. And that brings us to the, question or answering the question of what London Clay is.
00:01:04 - Essentially, it's a soil, it's a clay. That whole lot of London is sitting on that clay. So nobody knows where bedrock is in London. And of course I'm saying this with, joking matter. but there's abundant clay present in London that normally during these kind of excavation operations, this clay is being extracted from the ground, removed from the ground, and,
00:01:33 - And we know that this operation of repurposing the clay, excavating the clay from London for infrastructure development and repurposing it somewhere else as landfill is associated with significant embodied carbon and significant, significant cost. so what we are doing in, in this as part of this study, we thought, okay, we need to think out of the box and try to find ways to, repurpose that excavated clay,
00:02:03 - in high value application rather than landfill it and transporting kilometers away from London. The focus of that study was London Clay itself. So we first thought, okay, what can we do with London Clay? London Clay is a, a clay. So that takes us a step back to consider what can we do with clays? And very important, research accomplishment over the past years, in, in, in the material science field
00:02:35 - of clays for the replacement of Portland's men concrete in order to reduce concrete symboled carbon. So what we did in this case, we thought, okay, we can use other clays which are suitable for replacing Portland's main concrete. Why should we not try and use London clay for that purpose? That was never tried before, never tried before. so it was a bit of uncharted territory for us.

Repurposing London Clay for Sustainable Concrete

00:03:05 - to towards characterization of that material. so we started with collaboration with, different reputable, academic institutions and, also, consultancies. And, we derived a detailed plan, which involves material characterization, micro structural material characterization of the raw clay itself. And then we investigated methodologies to convert that clay to a usable material in concrete.
00:03:37 - or cal signate as we call it, in scientific terms. And, that material converts itself through calcination from, an inert material to a reactive material for using concrete. So we did this study of trying to identify or determine which are the suitable temperature ranges or, particle size distributions, grinding, and so on, which are optimum for converting the raw clay.
00:04:10 - works to a usable material and concrete with, some requirements for for performance. So at first when we started this investigation on the reactivity of lung and clay, I think it's worth mentioning that, a metric or a criterion for describing the reactivity of clays. And there's suitability for use as, Portland cement replacement in concrete is the carbonite content, which is a mineralogical,
00:04:40 - so carbonite is quite key in, in, in its presence in clays because it improves the reactivity of these clays. So the material characterization showed that London clays are low in carbonate content, let's say below 30%. And that could be somewhat problematic for achieving, for producing a very good, good quality cal sign clay material for using s for using instead of portal cementing concrete.
00:05:15 - and concrete development activities was that we could produce, good quality concrete by good quality, I mean, 40 to six megapascal strengths of, of concrete. And this is been considered as a relatively good quality concrete in, in the world of civil engineering, with, 50% to 70% replacement of Portland cement with, with London clay. So that was extremely encouraging with respect
00:05:46 - as a low cost, low carbon cement replacement in concrete. I think one of the most important conclusions, and at least the one that makes me feel the most excited is that we can Use, waste clays which are not so rich in called an A content. So waste clays, which would, nobody wants to use them essentially. we convert them in a usable supplementary cement tissue material for using concrete.

Utilizing Excavation Waste for Quality Concrete

00:06:15 - because over the past decade or even 15 years, we have seen several studies that are focusing on quite reactive clay. But I think our study really paved the way forward for looking into less reactive materials, more excavation wastes and their utilization in the production of structural concrete. So I think that this is the most important conclusion,
00:07:07 - the reactivity of material or the production of, of concrete strength. But as a key takeaway, I would like to say that we can produce good quality concrete, so up to, 40 or six megapascal strengths on a consistent manner, achieving good radiology, using this excavation waste, material.

Faculti AI can make mistakes

Faculti

Popular in Engineering

Control of a Wheelchair-Mounted Robotic Arm System

Spatiotemporal evaporating droplet dynamics on fomites enhances long term bacterial pathogenesis

Polyfluorene-Wrapped Carbon Nanotubes Decorated with Photocleavable Side-Chains

A Trusted and Privacy-Preserving Internet of Mobile Energy

Water Security: Why We Need Global Solutions

Decision-Making Principles for Better Software Design Decisions

Adaptive Traffic Signal Control With Deep Reinforcement Learning and High Dimensional Sensory Inputs

Suitability of excavated London clay as a supplementary cementitious material

Next in Civil Engineering

Guide

Platform and Category Pages

Contact Us

FAQs

Guide

Interview Process

For in-depth insights:

For news and opinion commentaries:

Page Structure

Popular in Engineering

Guide

Platform and Category Pages

Contact Us

FAQs

Guide

Interview Process

For in-depth insights:

For news and opinion commentaries:

Accessibility Options

Contrast Adjustment

Text Size Adjustment

Text Spacing Adjustment

Line Height Adjustment

Cursor Size Adjustment

Page Structure Options

Page Structure