Cementation of Cementation of DustDust
Young Hun YoonPeter Brimblecombe
University of East AngliaSchool of Environmental
Sciences, Norwich, NR4 7TJ, UK
0
2
4
6
0 25,000 50,000 75,000 100,000 125,000
Visitors/exposure period
/Gs
IMPACT OF VISITOR IMPACT OF VISITOR NUMBERSNUMBERSon DUST DEPOSITon DUST DEPOSIT
HCP
AEH
OPH
PREVIOUS WORK
2
PROBLEPROBLEMM
- High Humidity
- Biological attack- Chemical attack
- Physical behaviour
CEMENTATIONACCUMULATION
Some large particles disappearing!BECOME DEEPLY BECOME DEEPLY
EMBEDDED INTO FIBREEMBEDDED INTO FIBRE
RH change
3
100
200
300
400
30 35 40 45 50 55 60 65
RH
Ope
ning
/mic
rons
MOVING DUST!MOVING DUST! RH changeRH change
Measured by Dr D Bowden & Created by Prof. Peter Brimblecombe
4
DUST SEPERATIONDUST SEPERATION COLOUR CHANGECOLOUR CHANGE
Dust from proper left upper outer valance,KNOLE
Fibre
ParticlesOriginal Dust
18% w/w
82% w/w
5
A single particles A single particles adhered to adhered to
fibre surfacefibre surface
Many fine particles- fibre becomes dark
colour
DARK
COLOUR
COLOUR CHANGE
6
(a)
(b)
Excrement or egg from Excrement or egg from insect…?insect…?
7
BACTERIAL EXOPOLYMERSBACTERIAL EXOPOLYMERS
Silk fibers and bacteria after three months
of growth in high humidity.
SEMs: A. Tarnowski & C. McNamara Appl.Bio. DEAS Harvard University 8
CEMENTATION OF DUSTCEMENTATION OF DUST
Humidity and pollutants
may bind dust to
underlying surfaces
so sets cleaning frequency (Curtain from Eating Room)
Cementation?
9
EXPERIMENTEXPERIMENT Soil fines (63microns) + single
fibre or
Mixed with traces of salt and sugar in small dish
Exposed for about 3 months in HCP, Knole, Dover Tunnel
Lab work - 4 weeks exposure (at RH 35, 70, 80, 98%)
Weighing
10
HIGH HUMIDITY EXPOSUREHIGH HUMIDITY EXPOSURE
Concreted at High Humidity Knole & Dover Tunnel
Dust + sugar Dust + salt
11
COTTON AFTER A HUMID COTTON AFTER A HUMID WINTERWINTER
HCP Knole
12
0
1
2
3
4
5
Fibr
e W
eigh
t I
ncre
ased
(m
g)
RH 35%
RH 70%
RH 80%
RH 98%
Lab work: FIBRE WEIGHING
Soil + NaCl
Soil + Sugar Soil
weight 13
0
0.1
0.2
0.3
0.4
0.5
0.6
0 20 40 60 80 100 120
Humidity
Fibr
e W
eigh
t In
crea
sed
(mg)
Cotton Fibre + soil finesCotton Fibre + soil fines
Lab work: FIBRE WEIGHING
weight 14
weight
0123456789
10
Knole HCP Dover Tunnel
NaCL
Sucrose
Control
Low humidity in HCP shows small activity on cementation!
Exposures: FIBRE WEIGHING
15
Exposures: FIBRE WEIGHING
0
0.2
0.4
0.6
0.8
1
Knole HCP Dover Tunnel
Fibre
wei
ght
incr
ease
d (
mg)
Control
Control : without salt and sugar
weight 16
CONCLUSIONCONCLUSION
- Cementation control
- Cleaning frequency
&
20
SALT ENCRUSTATIONS
J.R.N. Tower Curing Works, 1880, Great Yarmouthreat Yarmouth
Fish washing box near salt store
in the building.
17
SALT ENCRUSTATIONS –
WOODEN BEAM WITH SALTWOODEN BEAM WITH SALT
0
10
20
30
40
50
60
70
conce
ntr
ati
on (
g/k
g)
Floor dust Storage Salt adhered towooden ceiling
Chloride
Sulphate
Nitrate
Salt adhered onto the wooden ceiling
Fish washing box and Plaster degraded of the wall.
x4
Dionex
18
J.R.N. Tower Curing Works, 1880, Great Yarmouthreat Yarmouth
Fish washing box near salt store
in the building.
Plate 2. Traditional dust flaps at Nostell Priory Library
DUST FLAPSDUST FLAPS : case study and : case study and applicationapplication
Plate1. Leather dust flaps at Library in Ickworth
House
Dust flap
(Credit: Katy Lithgow, NT)
19
CONCLUSIONCONCLUSION
- Cementation control
- Cleaning frequency
&
20