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A study on the mixed properties of green controlled low strength cementitious

Sung-Ching Chen
Sung-Ching Chen
, 
Wei-Ting Lin
Wei-Ting Lin
, 
Kae-Long Lin
Kae-Long Lin
 et 
Po-Yu Huang
Po-Yu Huang
   | 06 juil. 2021
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Publié en ligne: 06 juil. 2021
Pages: 59 - 74
Reçu: 16 févr. 2021
Accepté: 21 févr. 2021
DOI: https://doi.org/10.2478/msp-2021-0004
Mots clés
© 2021 Sung-Ching Chen et al., published by Sciendo
This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Fig. 1

Results of the 2019 Global Carbon Budget Survey (by country) [3].
Results of the 2019 Global Carbon Budget Survey (by country) [3].

Fig. 2

2019 Global Carbon Budget Survey Results (by Industry) [3].
2019 Global Carbon Budget Survey Results (by Industry) [3].

Fig. 3

SEM image of the CFA (100×).
SEM image of the CFA (100×).

Fig. 4

XRD composition analysis of the CFA.
XRD composition analysis of the CFA.

Fig. 5

SEM observation of the GGBS (1000).
SEM observation of the GGBS (1000).

Fig. 6

Penetration Resistance vs. Time Curve.
Penetration Resistance vs. Time Curve.

Fig. 7

Paste specimens for various CFA inclusion.
Paste specimens for various CFA inclusion.

Fig. 8

F0 specimens demoulded at four days.
F0 specimens demoulded at four days.

Fig. 9

Compressive strength development curves.
Compressive strength development curves.

Fig. 10

SEM photo of the T10 specimens under atmospheric exposure at 7 days.
SEM photo of the T10 specimens under atmospheric exposure at 7 days.

Fig. 11

EDS analysis of the T10 specimens under atmospheric exposure at 7 days.
EDS analysis of the T10 specimens under atmospheric exposure at 7 days.

Fig. 12

SEM photo of the 5h3 T10 specimens under atmospheric exposure at 28 days (5000).
SEM photo of the 5h3 T10 specimens under atmospheric exposure at 28 days (5000).

Fig. 13

EDS analysis of the 5h3 T10 specimens under atmospheric exposure at 28 days.
EDS analysis of the 5h3 T10 specimens under atmospheric exposure at 28 days.

Fig. 14

SEM photo of the 5h3 T10 specimens for water curing and indoor dry curing at 28 days (5000 magnification).
SEM photo of the 5h3 T10 specimens for water curing and indoor dry curing at 28 days (5000 magnification).

Fig. 15

Cumulative intrusion vs. pore size curves (28 days).
Cumulative intrusion vs. pore size curves (28 days).

Fig. 16

Relationship between a gel pore and a capillary pore (28 days).
Relationship between a gel pore and a capillary pore (28 days).

ACI 229 recommended dosage for the CLSM.

Material Recommended dosage (kg/m3)
Cement 30–120
Class F fly ash (when used instead of fine particles) 0–1200
Class C fly ash 0–210
Fine aggregate 1500–1800
Water 193–344
Water (when using Class F fly ash) 590

Proportioning design of the CLSM pastes.

Numbering CFA (%) GGBS (%)
F100 100 0
F75 75 25
F50 50 50
F25 25 75
F0 0 100

Fresh properties for the mixing materials of the CLSM.

Material Advantage Disadvantage
CFA Improve the consistency of the V type Minimum slump
Reduce the possibility of a box-type passage
Reduce stress resistance
GGBS Improve fluidity and slump Increase compression value
Improve stress resistance
Methylcellulose Improve consistency Reduce the possibility of a box-type passage
Extend V-type test time Retard
Superplasticizers Increase fluidity Expensive
Accelerators Offset time Reduce slump

Compressive strength of the paste specimens at seven days (MPa).

Paste specimens Value F100 F75 F50 F25 F0
1 – 4.71 8.14 10.00 –
2 – 4.51 6.76 9.80 –
3 – 4.61 7.84 9.71 –
Average – 4.61 7.58 9.84 –

Fluidities for the strength activity index testing.

Type Flowability (cm) Water (g)
GGBS 16.0–21.0 230–260
CFA 11.5–22.4 230–270

SCC grading table.

Grade Type 1 2 3
Box test (mm) Over 300 (R1 disorder) Over 300 (R2 disorder) Over 300 (Accessibility)
Flowability (mm) 650~750 600~700 500~650
V type test (sec) 10~25 7~20 7~20

Mix design for the activity index test (kg/m3).

Specimen No. Cement Standard sand CFA GGBS Water
A-C 500 1375 242
A-F 400 1375 100 252
A-S 400 1375 100 240

Weather observation data.

Age Temperature (°C) Max. temperature (°C) Min. temperature (°C) Relative humidity (%) Precipitation (mm) Precipitation hours (hr) Maximum hourly precipitation (mm) Sunshine hours (hr) Sunshine rate (%)
1 28.4 32.8 24.4 84 T 0.3 T 8.9 65.4
2 28.5 33.6 25.5 83 0.7 3.1 0.5 8.7 63.9
3 27.8 32.5 25.0 85 13.6 4.7 6.2 1.6 11.7
4 28.3 32.5 25.0 88 0.0 0.0 0.0 6.7 49.2
5 25.9 28.6 23.8 93 28.6 12.8 5.5 0.0 0.0
6 23.4 24.7 22.6 94 31.0 22.5 6.5 0.0 0.0
7 24.9 28.7 22.9 92 6.5 8.1 2.5 0.7 5.1
8 24.6 27.4 23.5 94 20.9 16.0 5.6 0.0 0.0
9 24.9 27.5 23.2 94 11.0 21.2 4.0 0.0 0.0
10 26.2 29.8 24.1 89 T 1.9 T 0.1 0.7
11 27.3 31.2 24.2 80 0.0 0.0 0.0 0.8 5.9
12 28.1 32.2 25.5 81 0.5 2.0 0.5 0.3 2.2
13 28.7 33.3 24.1 79 0.0 0.0 0.0 7.4 54.3
14 28.7 33.6 25.5 84 0.8 1.7 0.8 8.1 59.4
15 28.9 33.8 25.6 85 0.0 0.0 0.0 8.5 62.4
16 29.6 34.1 26.2 82 0.0 0.0 0.0 8.6 63.1
17 29.7 33.2 26.3 81 0.0 0.0 0.0 6.7 49.2
18 28.7 33.4 25.8 89 26.5 3.5 26.0 4.7 34.5
19 29.0 33.0 25.1 87 T 1.0 T 9.5 69.8
20 29.6 33.0 26.1 82 0.0 0.0 0.0 10.2 74.9
21 29.6 33.2 27.1 83 0.0 0.0 0.0 6.9 50.7
22 29.3 34.5 26.1 82 9.1 2.1 7.5 8.3 61.0
23 29.1 33.0 25.1 84 0.1 0.2 0.1 11.4 83.8
24 29.1 33.7 26.2 83 0.4 0.8 0.3 5.6 41.2
25 28.9 32.6 25.9 82 0.0 0.0 0.0 5.7 41.9
26 29.7 34.4 26.0 76 0.0 0.0 0.0 8.0 58.9
27 29.7 33.5 26.5 80 0.0 0.0 0.0 10.3 75.8
28 28.4 33.3 24.7 83 34.4 3.0 31.5 0.5 3.7

Chemical compositions of CFA.

Composition Value (%) Composition Value (%)
Sample I Sample II Sample I Sample II
Na2O 0.75 0.00 Fe2O3 3.49 3.34
MgO 1.82 2.15 NiO 0.00 0.00
Al2O3 19.27 12.21 Co2O3 0.00 0.05
SiO2 29.47 26.21 CuO 0.00 0.04
P2O5 0.47 0.67 ZnO 0.08 3.11
SO3 7.36 10.35 As2O3 0.00 0.00
Cl 0.07 0.14 Br 0.01 0.04
K2O 1.02 0.90 Rb2O 0.00 0.00
CaO 35.54 40.24 SrO 0.05 0.04
TiO2 0.55 0.49 ZnO2 0.00 0.00
Cr2O3 0.00 0.00 Y2O3 0.00 0.00
MnO 0.05 0.05 ZrO2 0.02 0.03

Mix design of CLSM (kg/m3).

Mix No. w/c Cement CFA GGBS Coarse Aggregates Fine Aggregates Water Superplasticizer Accelerator Adhesive
T1 31.5 94.7 155.5 1304.0 242.5 3.2 0.060
T2 47.3 142.0 233.3 806.8 376.4 3.2 0.060
T3 34.7 104.2 171.1 1204.5 269.3 3.2 0.090
T4 69.3 136.9 101.4 1204.3 269.3 3.2 0.320
T5 0.85 69.3 162.0 76.0 400.5 1204.2 268.9 22.1 3.2 0.410
T6 104.0 121.5 88.7 1204.2 267.4 5.0 0.473
T7 69.3 162.0 76.0 1204.2 262.0 10.0 0.473
T8 69.3 162.0 76.0 1204.2 262.0 10.0 0.410
T9 69.3 162.0 76.0 1204.2 268.0 4.0 0.410
T10 69.3 162.0 76.0 1204.2 268.4 3.6 0.410

Fresh properties of the CLSM.

Mix no. V type test (sec) Box test Flowability (cm) Tube fluidity (cm)
T1 6 Pass 59.5 20.0
T2 Severe bleeding
T3 4 Severe bleeding
T4 6 Did not pass 57.5 23.0
T5 7 Pass 64.0 21.5
T6 6 Did not pass 49.5 19.5
T7 17 Did not pass 38.0 15.0
T8 Rapid hardening
T9 11 Pass 46.5 18.5
T10 7 Pass 50.0 20.0

Designed compressive strength for various backfill materials [35, 36, 37].

Items Backfill material Compressive strength
1 Specification requirements 8.3 MPa (1200 psi)
2 Recommended strength 2.1 MPa (300 psi)
3 CLSM long-term compressive strength 0.3 MPa–2.1 MPa (50 psi–300 psi)
4 Equivalent to good compaction 0.35 MPa–0.7 MPa (50 psi–100 psi)
5 Foundation support 0.7 MPa–8.3 MPa (100 psi–1200 psi)
6 Subgrade 2.8 MPa–8.3 MPa (400 psi–1200 psi)
7 Can be manually mined 0.3 MPa (50 psi)
8 Reliable mechanical digging 0.7 MPa–1.4 MPa (100 psi–200 psi)
9 The strength that can be excavated only when using fine sand or fly ash as the granular material 2.1 MPa (300 psi)

Optimal mix design of the CLSM using a higher amount of cement replacement.

Material Value
Water–cement ratio 0.85
Cement 69.3 kg/m3
CFA 162.0 kg/m3
GGBS 76.0 kg/m3
Coarse aggregate 400.5 kg/m3
Fine aggregate 1204.2 kg/m3
water 268.4 kg/m3
Superplasticizers 22.5 kg/m3
Adhesives 0.410 kg/m3
Accelerators 3.6 kg/m3
Unit weight 2527 kg/m3

Chemical compositions of CFA and GGBS.

Composition CFA GGBS
Content, wt. (%)
Silicon dioxide (SiO2) 29.47 33.68
Aluminium oxide (Al2O3) 19.27 14.37
Ferric oxide (Fe2O3) 3.49 0.29
Calcium oxide (CaO) 35.54 40.24
Magnesium oxide (MgO) 1.82 7.83
Sulphur trioxide (SO3) 7.36 0.66
Others 3.05 2.93

Compressive strength (MPa).

Method 7-day 14-day 28-day
Atmospheric exposure (A) 2.84 5.20 5.78
Water curing (W) 2.94 4.51 5.39
Indoor dry curing (E) 3.43 4.31 5.59

Pozzolanic strength activity index results.

Mix no. Compressive Strength (MPa)
7 days 28 days
A-C 32.16 44.80
A-F 31.96 41.18
A-S 31.27 50.20
Material Strength Activity Index
7 days 28 days
CFA 99% 92%
GGBS 97% 112%

Chloride diffusion coefficient from the accelerated chloride migration test (10−12 m2/s).

Method 7-day 14-day 28-day
Atmospheric exposure (A) 2.62 2.21 0.51
Water curing (W) 3.02 1.43 0.14
Indoor dry curing (E) 3.90 1.89 1.75
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