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Wind Resistance Performance Evaluation of Cable-Type Curtain Wall System on Reinforced Concrete High-Rise Buildings

  • Hyun Soo Park
  • Jong Ho Won
  • Woong June Chung
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  1. Innovative Technologies of Structural System, Vibration Control, and Construction for Concrete High-rise Buildings

Abstract

In this research, a cable-type wall system that could replace the conventional aluminum curtain wall system for reinforced concrete high-rise buildings is proposed. The cable-type wall system is a newly developed system, which could be used as an existing exterior skin system, and can effectively support the wind load acting on the exterior of the high-rise buildings by the pre-induced initial tension force to the cable supporting the glass. The main advantages of the cable-type wall system are that the expense of construction could be reduced due to the simplicity of the construction. The experiment of structural analysis and air/water tightness was performed to evaluate its feasibility of industrialization. The structural performance of the cable-type wall system was evaluated through the structural analysis and the full-scale experiment to predict the initial pre-tension force and the design load displacement of the vertical one-way cable-type wall system that can be used for a typical floor of the high-rise building. The initial pre-tension force and structural behavior of the cable were analyzed by using the structural design program MIDAS-Gen. The maximum deformation value in the structural test was found to satisfy the AAMA condition, which is equal to the size of the facade skin system. The air/water tightness test was conducted to verify the performance. Test results show that the cable-type wall system satisfies the air/water tightness performance standards ASTM E283, E331 and AAMA 501.1-05 which are the most basic standards that the facade system must provide. As a result of this study, it is expected that the proposed cable-type wall system could be used for facade system, not only the structural performance but also air/water tightness performance are secured.

Keywords

curtain wall wind resistance initial pre-tension cable-type facade system structural performance air/water tightness performance 

1 Introduction

1.1 Research Background

Cable structures have been commonly used as structural systems in bridges such as suspension bridges and cable-stayed bridges to control the deflection of long-span structures, and recently they are used in building claddings. Cable structures, which are used for exterior materials of reinforced concrete structures, act on strong positive tension on cables instead of mullion and transom, and secure openness and ease of construction (Park 2002). A typical example is the cable network cladding system where the fixed hardware is installed at the edge points connected vertically and horizontally to fix square or rectangular glass in point shape (Park et al. 2014). This structure is similar to tennis rackets and the external force from the tennis ball causes deformation on the racket frame and tennis strings, which absorbs the energy and back again by the reaction force (Park 2018).

However, it is difficult to find a case in Korea as well as abroad that cable external systems are applied to the standard layer curtain wall of high-rise buildings, and is only applied to lobbies and large spaces of buildings (Park 2017). The reason why cable network systems are not being used as exterior materials for high rise buildings is the increased cost of establishing a fixed system of steel members supporting the cable connected vertically and horizontally (Georg et al. 2012). Therefore, to address these problems, this research suggests a cable system that is easy to achieve and build on behalf of aluminum or steel support members that are used as exterior materials for existing reinforced concrete buildings.

1.2 Research Objectives

Cable wall systems support glass by connecting cables in one direction only (Schlaich et al. 2005) offers the advantages of reducing the volume of frames than conventional aluminum enclosures, however the structural analysis of cable behavior is difficult and the construction method is not generally used (Feng et al. 1996). Also, due to the characteristics of the cable performing nonlinear behavior, it is difficult to predict initial tension and select members, and the design of an anchorage zone by strong tension is essential (Choi et al. 2018).

To make the cable system universally available in the curtain wall market, it is easy to predict the amount of variation of cables through the selection of point by point of design load and the accurate prediction of initial tension (Shi et al. 2010). Also, applying to the reference story of high-rise reinforced concrete structures requires a simple system that can complement the complex process of traditional aluminum curtain wall methods as shown in Fig. 1 (Choi et al. 2018). Therefore, to solve these problems, the initial tension and design of cables in vertical, one-way cable-type curtain wall system that can be applied repeatedly to the reference story of a high-rise reinforced concrete structure.
Fig. 1

Comparison of alum. C/wall system and cable C/wall system.

2 Experimental Plan

2.1 Structural Analysis Plan

In this study, the design wind pressure was calculated for the busiest areas, Seoul and Busan in Korea, based on the basic wind speed values for each region presented in the criteria of Korea Building Code (KBC) (2016) 0305.5.2. Design wind pressure Pc for external cladding over 20 m height was calculated by Eq. (1) for static pressure and Eq. (2) for negative pressure in (KBC 2016 0305.4.2, 4.3) as shown in Tables 1, 2.
$${{\text{P}}_{\text{c}}} = {{\text{k}}_{\text{z}}} {{\text{q}}_{\text{H}}} \left( {{{\text{GC}}_{\text{pe}}} -{{\text{GC}}_{\text{pi}}} }\right)\left( {{\text{N/m}}^{2} } \right) - \left( {{\text{KBC}}\;2016\;0305.4.2} \right).$$
(1)
$${{\text{P}}}{_{\text{c}}} = {{\text{q}}}_{{\text{H}}} \left( {{{\text{GC}}}_{{\text{pe}}} - {{\text{GC}}}_{{\text{pi}}} } \right)\left( {{\text{N/m}}^{2} } \right) - \left( {{\text{KBC}}\;2016\;0305.4.3} \right).$$
(2)
where Pc is a design wind pressure and GCpe is a peak pressure factor for external design.
Table 1

Comparison of design wind pressure between Seoul and Busan, (a) Seoul (importance factor 1.0/height of a building 199 m/height of a floor 4.5 m).

Span (m)

Exposure

A

B

1

Typical (+)

1.69 kPa

Typical (+)

2.07 kPa

Typical (−)

− 1.46 kPa

Typical (−)

− 1.74 kPa

Edge (−)

− 2.75 kPa

Edge (−)

− 3.26 kPa

Table 2

Comparison of design wind pressure between Seoul and Busan, (b) Busan (importance factor 1.0/height of a building 199 m/height of a floor 4.5 m).

Span (m)

Exposure

C

D

1

Typical (+)

4.41 kPa

Typical (+)

5.06 kPa

Typical (−)

− 3.70 kPa

Typical (−)

− 4.15 kPa

Edge (−)

− 6.95 kPa

Edge (−)

− 7.80 kPa

The criteria for calculating the reference load were set for the Busan area due to the higher design load. According to the Korean Building Code 0305.5.2., the design wind pressure of the exterior surface of approximately 200 m skyscraper is a static pressure of 5.06 kPa, negative pressure 1 (typical) of − 4.15 kPa and negative pressure 2 (edge) of − 7.80 kPa, corresponding to the surface roughness category D of the Busan area with a basic wind speed of 38 m/s. Since the design wind pressures may differ slightly depending on the effective projected area and location of the cladding, the reference wind pressure was set at 5.0 kPa, similar to the external static pressure of the design load above.

Through the case studies of a typical high-rise office building, the design conditions were determined by applying a layer height of 4.5 m, module 1.0 m to 1.25 m.

The structural analysis model implements a 20 mm diameter cable at 2 span with 4.5 m length and the curtain wall module for loading design wind pressures of 5.0 kPa is 1.0 m and 1.25 m. To check the deformations of cables according to the changes in tension of cables and the change in initial tension, the initial tensions were 20%, 25%, 30%, and 40% of the maximum tensile strength of cables (refer to Figs. 2 and 3).
Fig. 2

Structural analysis model.

Fig. 3

Structural analysis model (initial force 20%, 25%, 30%, 40%).

The loading position is designed to accommodate the lower spandrel part 1000 mm, view part 2900 mm, and upper spandrel part 600 mm from the floor level according to the typical window design conditions.

MIDAS GEN Program (MIDAS 2016) was used for the structural analysis. The nonlinear analysis ensures that the displacement of the cable at each point is within the allowable limit defined in American Architectural Manufacturers Association (AAMA) (2002).

2.2 Test Specimen Design

A cable tensile force device was constructed using a steel tube pipe to measure the tensile strength of the cable supporting the glass as shown in Fig. 4. Two spans in two stories with story height of 4.5 m specimen was tested, which is in equivalent condition as analytical model. Breaking load (Pbreak) of the 20 mm diameter spiral cable used in the test was 324 kN. Material properties of cable is shown in Table 3.
Fig. 4

Test of cable wall system.

Table 3

Material properties of cable.

Diameter (mm)

Modulus of elasticity (GPA)

Area (mm2)

Breaking load (kN)

Ultimate strength (MPa)

20

160

240

324

1470

The specimen was tested horizontally. A vertical force was applied to the specimen at the positions of 1000 mm and 2900 mm from the bottom where the transoms are located as shown in Fig. 5. To estimate the proper initial tension on the same cable, the positive tension of the cable changed to 20%, 25%, 30%, and 40% of the cable breaking tensile strength to check displacement and stress.
Fig. 5

Test setup and measurement.

Since the tension of cables varies greatly according to the temperature change after the positive tension is applied, the cables shall be tested at the room temperature so that no change in tension occurs after the positive tension was applied. It was required to reconfirm the change of tension through the force measuring device after the tensile force is applied to load the tensile force accurately.

2.3 Air/Water Tightness Mockup Test

The purpose of this study is to propose a cable wall system as a complete external cladding, which requires verification of the basic air/water tightness performance of the cladding. Therefore, three spans in two stories, which was the basic condition of the mock-up of the cladding, were implemented in the same way as the actual construction conditions including fixed glass, opened glass, and even structures for verification according to the American Society for Testing Materials (ASTM) E283-04 (2002) and ASTM E331-00 (2002).

The air tightness performance test was conducted to maintain a test standard pressure of 74.5 kN/m2 on the specimen for the test conditions of ASTM-E283, and then air flow from the specimen was measured as shown in Figs. 6 and 7.
Fig. 6

General arrangement of the air leakage test apparatus.

Fig. 7

Vent operation and air tightness performance test.

The water tightness test was conducted on the specimen to check for water leaks of 204 L/m2 spraying for 15 min while maintaining a static pressure 720 Pa specified in the specification ASTM-E331 to comply with the experimental conditions as shown in Figs. 8 and 9.
Fig. 8

Catch box for calibrating water-spray system.

Fig. 9

Air/water tightness performance test.

3 Structural Analysis and Experimental Results

3.1 Structural Analysis Results

Structural analysis is shown in Table 4 by performing a geometric nonlinear analysis using the MIDAS GEN program. In the case of Span 1.0 m for 5.0 kPa, the international allowable deflection L/50 (AAMA 1996) was satisfied for all four positive initial tensions which were 20%, 25%, 30%, and 40% of Pbreak. Also, the results demonstrates that the allowable deflection is satisfied for span 1.25 m with 5.0 kPa loads as shown in Table 5.
Table 4

W = 1.0 m structural analysis result.

Diameter (20 mm)

Pbreak (kN)

Span = 1.00 m

0.20Pbreak

0.25Pbreak

0.30Pbreak

0.40Pbreak

Pinitial (kN)

324

64.8

81.0

97.2

129.6

Δact (mm)

72.3

66.9

61.9

52.9

Δallow (mm)

90 (= L/50)

Δactallow

80.3

74.4

68.8

58.8

Pact (kN)

112.5

121.4

131.3

153.2

Pact/Pbreak

34.7%

37.5%

40.5%

47.3%

Pinitial: initial force.

Pbreak: breaking force.

Δact: actual deflection.

Δallow: allowable deflection.

Pact: actual tensile force.

Table 5

W = 1.25 m structural analysis result.

Diameter (20 mm)

Pbreak (kN)

Span = 1.25 m

0.20Pbreak

0.25Pbreak

0.30Pbreak

0.40Pbreak

Pinitial (kN)

324

64.8

81.0

97.2

129.6

Δact (mm)

81.1

76.0

71.1

62.1

Δallow (mm)

90 (= L/50)

Δactallow

90.2

84.5

79.0

69.0

Pact (kN)

125.2

133.6

142.8

163.2

Pact/Pbreak

38.6%

41.2%

44.1%

50.4%

The member stress of the cable was determined based on the cable design code KASS (2009), and the allowable load of the cable is equal to the breaking load divided by the safety factor 3 and the short-term stress coefficient multiplied by 1.33 for the wind load.

The results of allowable tensile force calculated from the results of the structural analysis are shown in Table 6. Cable member stresses were within acceptable limits at a force ratio of about 90% to the tensile force of up to 30%. At 40% of the tensile strength, about 7% of the allowable stress was exceeded for span 1.0 m specimen, and approximately 14% of the allowable stress for span 1.25 m specimen. Typically, the cable positive tension should not exceed the allowable stress (breaking force/3) on the long-term load, which is consistent with the test results. However, the allowable load for short-term loads is about 44% of the breaking load, which is somewhat beyond stress at 40% full tension, but with margin up to the breaking load, further studies are required for economic design under the conditions of the applied load.
Table 6

Force ratio of the cable.

W (m)

Pinitial

Pact (kN)

Pbreak (kN)

Pallow (kN)

Force ratio

Remarks

1.0

0.20Pbreak

112.5

324

143.64

0.783

O.K

0.25Pbreak

121.4

0.845

O.K

0.30Pbreak

131.3

0.914

O.K

0.40Pbreak

153.2

1.067

N.G

1.25

0.20Pbreak

125.2

324

143.64

0.872

O.K

0.25Pbreak

133.6

0.930

O.K

0.30Pbreak

142.8

0.994

O.K

0.40Pbreak

163.2

1.136

N.G

Pallow: allowable tensile force = 1.33Pbreak/3 (KASS 2009).

3.2 Structural Test Results

In the experiment, the cables were subjected to tension in the range of 20%, 25%, 30%, and 40%. In the same condition, the cables were tested sequentially, and they were repeatedly applied under the same conditions. For the design load, the results were verified by applying the load to 1.0 m specimen and the final result was confirmed after the additional load applied to 1.25 m specimen.

For the span 1.0 m for 5.0 kPa, all four initial tensions (20%, 25%, 30%, and 40%) were found to satisfy the international acceptable deflection L/50 as shown in Table 7. In addition, span 1.25 m for 5.0 kPa loads met the allowable deflection L/50 as shown in Table 8.
Table 7

W = 1.0 m Test result.

Diameter (20 mm)

Pbreak (kN)

Span = 1.00 m

0.20Pbreak

0.25Pbreak

0.30Pbreak

0.40Pbreak

Pinitial (kN)

324

64.8

81.0

97.2

129.6

Δact (mm)

64.3

59.5

55.4

52.2

Δallow (mm)

90 (= L/50)

Δactallow

71.5

66.1

61.6

58.0

Pact (kN)

110.8

119.2

127.5

152.5

Pact/Pbreak

34.2%

36.8%

39.3%

47.1%

Table 8

W = 1.25 m test result.

Diameter (20 mm)

Pbreak (kN)

Span = 1.25 m

0.20Pbreak

0.25Pbreak

0.30Pbreak

0.40Pbreak

Pinitial (kN)

324

64.8

81.0

97.2

129.6

Δact (mm)

74.4

69.1

65.2

61.9

Δallow (mm)

90 (= L/50)

Δactallow

82.7

76.8

72.5

68.8

Pact (kN)

120.9

129.8

137.7

160.8

Pact/Pbreak

37.3%

40.1%

42.5%

49.6%

As shown in Table 9, cable tension showed similar results as the structural analysis results. Up to 30% of the positive tension, the result was within the allowable stress range, however at 40% of the positive tension, stress on width of 1.0 m and 1.25 m exceeded 6.1% and 11.9% of allowable stress range, accordingly. As initial tension increases, actual tension increased and displacement decreased. Comparison of the results of the experiment and the structural analysis are shown in Fig. 10.
Table 9

Force ratio of the cable.

W (m)

Pinitial

Pact (kN)

Pbreak (kN)

Pallow (kN)

Force ratio

Remarks

1.0

0.20Pbreak

110.8

324

143.6

0.771

O.K

0.25Pbreak

119.2

0.830

O.K

0.30Pbreak

127.5

0.887

O.K

0.40Pbreak

152.5

1.061

N.G

1.25

0.20Pbreak

120.9

324

143.6

0.842

O.K

0.25Pbreak

129.8

0.904

O.K

0.30Pbreak

137.7

0.959

O.K

0.40Pbreak

160.8

1.119

N.G

Fig. 10

Comparison of test and analysis for tensile force.

In Fig. 11, the change in displacement between the experiment and the structural analysis results showed 90% and 99% match at the initial tensile force 30% and 40%, accordingly.
Fig. 11

Comparison of test and analysis for deflection.

3.3 Results of Air/Water Tightness Mock-up Experiments

For considering the various ambient conditions, air/water tightness tests according to ASTM were conducted. The results of the experiments in accordance with ASTM E283 air tightness performance test are shown in Table 10. The experiment measured the leakage by applying a test standard pressure of 75 Pa and compared it to the allowable values of 0.06 CFM/ft2 (fixed area) and 0.25 CFM/ft (opened area).
Table 10

Conversion of air flow rate during air tightness test.

Conversion of air flow under standard test conditions from measured air leakage

Measured air flow

Standard test conditions

W

Air flow under standard test conditions (CFM)

Location

Total (Qt)

Extraneous (Qe)

Net specimen (Qs)

Pressure

Temperature

Air density (Ws)

Fixed area

4.28

2.0

2.28

1013 (hpa)

20.8 (°C)

1.202 (kg/me)

1.212 (kg/me)

2.28

Vent (project window)

5.60

4.28

1.32

1.32

Atmospheric conditions at the location of air flow meter during the test: Atmospheric temperature (T): 21.2 °C, Atmospheric pressure (B): 1023.0 hpa, Relative humidity: 25.2%

Qst = Q (W/Ws)1/2, W = 3.485×10−3 (B/(T + 273)).

Q = airflow at non-standard conditions, Qs = Qt − Qe.

Qst = airflow corrected to standard conditions.

Ws = density of air at reference standard conditions − 1.202 kg/m3 (0.075 lb/ft3).

W = density of air at the test site, kg/m3 (lb/ft3).

B = barometric pressure at test site corrected for temperature, Pa (in.Hg), and

T  = temperature of air at flowmeter, °C.

The total size of the curtain wall is 4.18 m by 9.045 m, so it is 37.81 m2 (406.95 ft2) and the ventilation perimeter for window is 2 × [2 (1.03 + 0.53)] m, which is 6.24 m (20.47 ft). The volume of air (Qst) is calculated as 2.28 CFM and 1.32 CFM as shown in Table 10. Total leakages of air per unit under fixed and opened conditions were 0.006 CFM/ft2 and 0.064 CFM/ft, respectively. These values satisfies the allowable limit of 0.064 CFM/ft2 and 0.25 CFM/ft, respectively.

The water tightness performance test was conducted under the static and dynamic pressure. Experimental conditions under static pressure as per ASTM E331-00 were,
  1. Test pressure: + 73.2 kgf/m2 (+ 720 Pa, 15.0 psi)/AAMA 501-15 recommendation.

     
  2. Amount of spray water: 204 L/m2 h,

     
  3. Duration: 15 min,

     
  4. Tolerance: no uncontrolled water leakage.

     
Experiments under dynamic pressure was conducted in accordance with AAMA 501.1-05 using the aircraft engine to spray water while blowing the air. These conditions were,
  1. Test pressure: wind speed equal to static pressure + 73.2 kgf/m2 could be calculated as \({\text{q}}_{0} \, = \,\frac{1}{16}{\text{V}}_{0}\), q0: basic velocity pressure (kgf/m2), V0: wind speed (m/s), \(\therefore {\text{V}}_{0} \, = \,\sqrt {q_{0} \times 16} = \sqrt {73.2 \times 16} \, = \, 3 4.0 5\) m/s,

     
  2. Amount of spray water to live: 204 L/m2 h,

     
  3. Duration: 15 min,

     
  4. Tolerance: no uncontrolled water leakage.

     

Water leakage was not detected under both static and dynamic pressure, and excellent water tightness quality was verified.

4 Conclusions

In this study, a new curtain wall system was proposed that could replace the aluminum cladding system used as the exterior skin material of the reinforced concrete high-rise building and was evaluated the structural and air/water tightness performance. The final results from this study are as follows:
  1. 1.

    The newly proposed cable-type curtain wall system is expected to reduce construction costs as a result of the reduction of construction period compared to the existing method.

     
  2. 2.

    The structural performance of cables against the design wind pressure was verified through a nonlinear analysis of the cable system.

     
  3. 3.

    Comparing the results of a nonlinear structural analysis of the proposed cable wall structural system with the results of a full-scale structural experiment shows similar results to the maximum load and displacement values, demonstrating reliable results.

     
  4. 4.

    For the positive initial tension applied to cables in the proposed cable system, 30% of the breaking force was considered most appropriate.

     
  5. 5.

    The air/water tightness demand performance of the proposed cable-type curtain wall system as a cladding material has been found to be suitable for ASTM E283, E331 and AAMA 501.1-05, thus it could be maximize energy efficiency.

     

Notes

Authors’ contributions

HSP wrote the manuscript in consultation with JHW and WJC. All authors read and approved the final manuscript.

Acknowledgements

This research was supported by a Grant (18AUDP-B106327-04) from Architecture & Urban Development Research Program funded by Ministry of Land, Infrastructure and Transport of Korean Government.

Competing interests

The authors declare that they have no competing interests.

Availability of data and materials

The datasets used and/or analysed during the current study are available from the corresponding author on reasonable request.

Funding

Not applicable.

Publisher’s Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

References

  1. AAMA (1996). Aluminum curtain wall design guide manual. Schaumburg: American Architectural Manufacturers AssociationGoogle Scholar
  2. AAMA. (2002). Maximum allowable deflection of framing systems for building cladding components at design wind load (pp. 33–72). Schaumburg: American Architectural Manufacturers Association.Google Scholar
  3. Architectural Institute of Korea. (2016). Korean building code and commentary (pp. 108–170). Seoul: Architectural Institute of Korea.Google Scholar
  4. ASTM E283-04. (2002). Standard test method for determining rate of air leakage through exterior windows, curtain walls, and doors under specified pressure differences across the specimen (pp. 1–4). West Conshohocken: ASTM International.Google Scholar
  5. ASTM E331-00. (2002). Standard test method for water penetration of exterior windows, skylights, doors, and curtain walls by uniform static air pressure difference (pp. 1–4). Philadelphia: ASTM.Google Scholar
  6. Choi, S., Won, J., Park, H., & Ha, Y. (2018). Wind load performance evaluation of curtain wall system. WEIK, 22(1), 19–23.Google Scholar
  7. Feng, R.-Q., Ye, J.-H., Wu, Y., & Shen, S.-Z. (1996). Mechanical behavior of glass panels supported by clamping joints in cable net facades. Journal of Steel Structures, 12(1), 33–72.Google Scholar
  8. Georg, J., Jim, M., Jeff, D., Gord A., Dejan E. (2012). Design and construction of a 30-metre-high glazing wall supported by cable trusses. In Canadian Society for Civil Engineering, 3rd International Structural Specialty Conference, Edmonton, STR-1135 (pp. 1–10).Google Scholar
  9. Korea Association for Spatial Structures. (2009). Design code and commentary for cable structures (pp. 93–109). Seoul, Korea: Kimoondang.Google Scholar
  10. MIDAS Information Technology Co. Ltd. (2016). Analysis & design (pp. 14–81). Seoul: MIDAS Information Technology Co. Ltd.Google Scholar
  11. Park, H.-S. (2017). Study on the cable wall system applied to reinforced concrete exterior. Journal of the Korea Academia-Industrial Cooperation Society, 18(3), 579–585.Google Scholar
  12. Park, J. S., Lee, C. H., Woo, W. T., Chung, K. R. (2014). The loading test of Cablenet System. In Proceedings of AIOK Spring Conference (pp. 339–340).Google Scholar
  13. Park, S.-W. (2002). Structural glass-system in Roof and Facade. Journal of the Korean Association for Spatial Structures, 2(3), 1–28.Google Scholar
  14. Park, S.-W. (2018). Glass architecture (pp. 160–180). Seoul, Korea: Wooribook.Google Scholar
  15. Schlaich, J., Schober, H., & Moschner, T. (2005). Prestressed cable net facades. Structural Engineering International, 15(1), 36.CrossRefGoogle Scholar
  16. Shi, G., Zuo, Y., Shi, X., Shi, Y., Wang, Y., & Guo, Y. (2010). Influence of damages on static behavior of single-layer cable net research article. Frontiers of Architecture and Civil Engineering in China, 4(3), 382–395.CrossRefGoogle Scholar

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Authors and Affiliations

  1. 1.College of Design and ArtShinhan UniversityUijieongbuSouth Korea
  2. 2.Citywall ENG Co. Ltd.SeongnamSouth Korea
  3. 3.Department of Architecture and Civil EngineeringUniversity of BathBathUK

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