cyprus 16th concrete conference 2009
TRANSCRIPT
Crushed limestone aggregates for concrete and mortars: Tests according to ΕΝ 12620, EN 13043, EN 13242 και EN 13139 standards.
Dimitris Xirouchakis, GeoTerra Ltd – Geomechanics & Quality Control Laboratory
Alexis Theodoropoulos, Α. Theodoropoulos – P. Moskofogoglou Pty. – Q4U Consulting Engineers
Limestone Aggregates
• Chemistry / Mineralogy• Physical & Mechanical Characteristics• Observations - Correlations
Chemistry / Mineralogy
96,1% CaCO3 (90,8 – 99,0 %)
0,66% MgO (0,15 – 2,66 %)
1,22% SiO2 (0,22 – 6,03 %)
0,08% Al2O3 (0,02 – 0,19 %)
0,07% Fe2O3 (0,01 – 0,28 %)
0,05% Na2Oeq (0,03 – 0,06 %)
XRD: 95,7 – 99,5% Cc
0,8 – 3,3% Dol
<1% Qz, Fe-oxides
Average apparent density:
(2,66 ± 0,01 g/cm3)
CaCO3 (2,71 g/cm3)
CaMg(CO3)2 (2,85 g/cm3)
CaFe(CO3)2 (3,20 g/cm3)
Heavy metals
min max μ Global average Alarm values
Co mg/kg <0,5 3,8 0,4 0,1
Ni mg/kg <0,5 33,5 9,1 20 900
Cr mg/kg <0,5 22,0 8,4 11 1000
Cd mg/kg <0,1 0,6 0,0 0,035 60
Pb mg/kg <1,0 5,8 1,1 9
Sb mg/kg <0,02 0,8 0,1 0,2
As mg/kg <0,01 1,1 0,4 1 140
Hg mg/kg <0,005 0,0 0,04 80
# Turekian & Wedepohl 1961. * Industrial sites, Germany, EUR 22805 EN 2007 JRC Ispra
Alkali – silica reaction: Innocuous aggregates
0.0 0.1 1.0 10.0 100.0 1000.00
400
800
1200
Sc mmol/l
Rc
mm
ol/
l
Field of innocuous aggregates
Sand
0.0 0.1 1.0 10.00
20
40
60
80
100
mm
Pas
sin
g (
%)
min max μ
MB (0/2) g/kg 0,2 1,2 0,5SE (0/2) % 52 81 69Ecs (0/4) sec 14 20 21ρα Mg/m3 2,522 2,743 2,697WA24 % 0,5 1,1 0,9
MS % 0,2 7,4 3,4
LPC % 0,000 1,990 0,210WS % 0,000 0,570 0,084ρb Mg/m3 1,372 1,754 1,603
Fine gravel
min max μ
ρα Mg/m3 2,643 2,746 2,704
WA24 % 0,3 0,8 0,5
MS % 0,4 7,4 2,9
LA % 21,0 42,0 28,3
MDE % 8,5 32,6 17,5
SI % 5,1 29,5 13,5
FI % 7,7 24,2 14,6VLA % 1,0 4,6 2,3
ρb Mg/m3 1,328 1,505 1,393
0.0 0.1 1.0 10.0 100.00
20
40
60
80
100
mm
Pas
sin
g (
%)
Coarse gravelmin max μ
ρα Mg/m3 2,611 2,727 2,698
WA24 % 0,3 0,6 0,4
MS % 0,1 7,4 2,8
LA % 17,0 42,0 28,6
MDE % 9,9 32,6 18,9
SI % 6,0 22,2 13,4
FI % 4,8 23,6 12,1
VLA % 0,2 4,6 1,9
ρb Mg/m3 1,281 1,466 1,378
0.0 0.1 1.0 10.0 100.00
20
40
60
80
100
mm
Pas
sin
g (
%)
MB vs SE
0.0 0.3 0.5 0.8 1.0 1.3 1.5 1.8 2.00
10
20
30
40
50
60
70
80
90
f(x) = NaN x + NaNR² = 0
ΜΒ
SE
FI vs SI
0 10 20 30 40 500
10
20
30
40
50
60
f(x) = NaN x + NaN
FI (%)
SI
(%)
Basaltic aggregates: Pétursson 2000
LA vs MDE
0 10 20 30 40 500
10
20
30
40
50
f(x) = NaN x + NaNR² = 0
LA
MD
E
VLA vs MS
0 1 2 3 4 5 6 7 8 9 100
2
4
6
8
10
f(x) = NaN x + NaNR² = 0
MS (%)
VLA
Conclusions
1. Aggregates derive from poor (85,0 – 93,5% CaCO3) to high quality (>98,5% CaCO3) limestones
2. They consist of 95,7 – 99,5% calcite, 0,8 – 3,3% dolomite <1% quartz, Fe oxides.
3. Heavy metals concentration is typical for limestone and at non-toxic levels4. Alkali-silica reaction: Innocuous materials5. Statistically significant correlations (>|0,5|) are observed among MB – SE, FI
– SI, LA - MDE, VLA – MS. No correlation is observed between MDE and WA24, and SiO2 content and MDE reported in igneous aggregates.