1 Introduction
Project title | Location of operation | Operation year | Operated track length (km) |
---|---|---|---|
Phase 1 | Japan (Tabata-Shinjuku-Tamachi) | 1998 | 35 |
Phase 2 | Japan (Tabata-Tokyo-Tamachi) | 2002 | 111 |
Phase 3 | Japan (Tokyo metro) | 2007 | 182 |
– | South Korea Urban Railway | 2003 | – |
– | South Korea (Seoul metro) | 2007 | – |
– | South Korea (Busan-Yangsan metro track 2) | 2009 | – |
2 Mortar Tests
2.1 Materials
2.1.1 Cement
Main chemical components (%) | ||||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
C3S | C2S | C3A | C4AF | CaSO4 | Al2O3 | Fe2O3 | MgO | L.O.I | I.R | |||||||||
51 | 25 | 12.2 | 7.2 | 2.6 | 5.6 | 3.7 | 2.6 | 1.2 | 0.3 |
Physical properties | ||||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Fineness (\(\mathrm{cm}^2/\mathrm{g}\)) | Retained on sieve #70 (%) | Autoclave expansion (%) | Normal consistency (%) | Setting time (min) | Compressive strength (MPa) | |||||||||||||
Initial | Total | 3 days | 7 days | 28 days | ||||||||||||||
2528 | 10.95 | 0.56 | 25.1 | 175 | 245 | 15.6 | 23.6 | 43.1 | ||||||||||
References | ASTM C204 (2016) | ASTM C136/C136M (2014) | ASTM C151/C151M (2016) | ASTM C187 (2016) | ASTM C191 ( 2013a) | ASTM C109/C109M (2013) |
2.1.2 Sand
Main chemical components (%) | ||||||
---|---|---|---|---|---|---|
SiO2 | Al2O3 | Fe2O3 | CaO | Na2O | K2O | L.O.I |
97.1 | 0.8 | 0.6 | 0.5 | 0.3 | 0.6 | 0.2 |
Sand type | Physical properties | |||||
---|---|---|---|---|---|---|
Specific density (ton/m3) | Humidity (%) | Mohs hardness | ||||
D11 | 2.62 | 0.21 | 7 | |||
NO. 161 | 2.68 | |||||
NO. 131 | 2.65 | |||||
NO. 181 | 2.73 |
2.1.3 Water
2.1.4 Superplasticizer
2.2 Mortar Test Plan
Parameters | Test type | |||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Compressive strength (ASTM C109/C109M, 2013) | Fluidity test (ACI304.1-R-92, 1997) | |||||||||||||||
Cement content (kg/m3) | 750 | 800 | 850 | 750 | 800 | 850 | ||||||||||
Age (day) | Number of constructed specimens | Number of tests on fresh mortar | ||||||||||||||
w/c | ||||||||||||||||
0.35 | 0.4 | 0.35 | 0.4 | 0.35 | 0.4 | 0.35 | 0.4 | 0.35 | 0.4 | 0.35 | 0.4 | |||||
1 | 3 | 3 | 2 | 3 | 4 | 3 | Impossible | 4 | Impossible | 3 | 3 | 4 | ||||
3 | 4 | 3 | 4 | 4 | 4 | 4 | ||||||||||
28 | 3 | 3 | 3 | 4 | 3 | 3 |
3 PAC Tests
Type | Specific weight (ton/m3) | Los Angles abrasion (%) | Micro-deval abrasion (%) | Water absorption (%) | Point load index (MPa) | Uniaxial compressive strength (MPa) | |
---|---|---|---|---|---|---|---|
Uncorrected | Corrected | ||||||
Andesite | 2.26 | 13 | 18.8 | 1.34 | 8.82 | 7.60 | 158.7 |
3.1 Developed Injection Apparatus
3.2 PAC Test Plan
Sand mix | Sand type | |||
---|---|---|---|---|
D11 | 131 | 161 | 181 | |
Sand mix 1 | 0% | 30% | 50% | 20% |
Sand mix 2 | 25% | 25% | 50% | 0% |
w/c | Ballast grade | Sand mix |
---|---|---|
0.4 | Ballast grade 1 | Sand mix 1 |
0.35 | ||
0.4 | Ballast grade 4 | |
0.35 | ||
0.4 | Ballast grade 1 | Sand mix 2 |
0.35 | ||
0.4 | Ballast grade 4 | |
0.35 |
3.2.1 SE and SPM Tests
3.2.2 SNM Test
3.2.3 SPR Test
3.2.4 SNR Test
3.3 PAC Beams Instrumentation
4 Results and Discussion
4.1 Mortar Test Results
4.1.1 Fluidity Time
4.1.2 Compressive Strength
4.1.3 Flexural Strength
4.2 PAC Test Results
4.3 PAC Beams Test Results
4.3.1 SE Results
4.3.2 SPM Results
4.3.3 SNM Results
4.3.4 SPR Results
4.3.5 SNR Results
5 Conclusion
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By changing the water-to-cement ratio in the mortar in the range of 0.3 to 0.5, the best-recommended fluidity time for the injectable mortar specimens was at least 70 s. The highest values of compressive and flexural strength of mortar at the water-to-cement ratio of 0.4 with 800 kg/m3 of cement content were obtained as 7.13 and 0 MPa for 1 day, 25.93 and 3.94 for 3 days, and 28.88 MPa and 6.57 MPa for 28 days, respectively.
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The highest compressive strength of the concrete specimen without the need for injection apparatus was obtained at the water-to-cement ratio of 0.4, sand composition of 2 (25% D11 sand, 25% sand 131, and 50% sand 161), and ballast grade 1, which possessed a 1-day compressive strength of 2.55 MPa, 3-day 7.32 MPa, and 28-day 16.4 MPa. According to the studies conducted on the 25MGT (million gross tons which annually pass through the track) axial load train, the minimum compressive strength required based on the numerical analysis performed by these authors was 13 MPa to satisfy the design requirements.
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The maximum bending force in the non-sleeper concrete beam midspan was 177.5 kN, which is higher than the breakdown achieved by ACI318, reported as 171.62 kN.
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In sleeper-included beams, the maximum force tolerated by PAC was 151.02 kN, while the sleeper tolerated 150.04 kN, and then complete failure occurred. This is less than the fracture force obtained by non-sleeper concrete beams, which is 177.5 kN, due to the use of sleepers in the construction of PAC beams and the decrease in the height of concrete beams. This force generated a moment of 55.25 kN m in the PAC beam, which is much larger than that generated by a 25-ton axle train. Moreover, the maximum force applied to the positive sleeper rail seat was 214.76 kN, which generated 32.5 kN m in the PAC beam, much larger than the moment suggested in the AREMA code.
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The maximum force applied at the negative bending center of the sleeper-included PAC beam and the maximum force applied at the vertical negative location of the PAC beam rail seat equaled 251.05 and 227.12 kN, which generated the moments of 91.84 kN m and 38.21 kN m, respectively. These values are much larger than the moment generated by the 25-tons axial freight train according to the relations in AREMA.