Effect of SiO₂ Aerogel-cement Mortar Coating on Strength of Self-Compacting Concrete after Simulated Tunnel Fire

Abstract

In order to facilitate self-compacting concrete to be better used in tunnel linings that can resist fires, a SiO₂ aerogel-cement mortar coating was prepared. Based on the HC curve, a self compacting concrete cube specimens coated and uncoated with SiO₂ aerogel-cement mortar (SiO₂-ACM) were heated to simulate tunnel fire for 0.5, 1, 1.5, 2, 2.5, 3 and 4 h, respectively.The residual compressive strength was tested after the specimens were cooled to room temperature by natural cooling and water cooling. The results show that, the damages of specimens become more serious as fire time goes on, but the residual strength of specimens coated with SiO₂-ACM is always higher than that of uncoated with SiO₂-ACM. In addition, the residual strength of specimens cooled by water cooling is lower than that of natural cooling. However, for the specimens coated with SiO₂-ACM, the adverse effects of water cooling are lessened. With the increase of fire time, the protective effect of SiO₂-ACM is still gradually improved. Finally, a formula was established to predict the residual 150 mm cube compressive strength of specimens protected by SiO₂-ACM after a simulated tunnel fire.

Keywords

self-compacting concrete / SiO₂ aerogel-cement mortar / simulated tunnel fire / residual compressive strength / natural cooling / water cooling

References

[1] Choi Y, Kim W C B. Flowability and Strength Properties of High Flowing Self-Compacting Concrete Using for Tunnel Lining[J]. International Journal of Concrete Structures and Materials, 2010, 2(2): 145-152.

[2] Okamura H, Ouchi M. Self-Compacting Concrete[J]. Journal of Advanced Concrete Technology, 2007, 1(1): 5-15.

[3] Ingason H, Li Y Z, Appel, et al. Large Scale Tunnel Fire Tests with Large Droplet Water-Based Fixed Fire Fighting System[J]. Fire Technology, 2016, 52(5): 1539-1558.

[4] Xargay H, Folino P, Sambataro, et al. Temperature Effects on Failure Behavior of Self-compacting High Strength Plain and Fiber Reinforced Concrete[J]. Construction and Building Materials, 2018, 165: 723-734.

[5] Abeyruwan H. Properties of Strength and Pore Structure of Reactive Powder Concrete Exposed to High Temperature[J]. ACI Mater., 2015, 112(2): 319-320.

[6] Memon S A, Shah S F A, Khushnood, et al. Durability of Sustainable Concrete Subjected to Elevated Temperature — A Review[J]. Construction and Building Materials, 2019, 199: 435-455.

[7] Sadrmomtazi A, Tahmouresi B. Effect of Fiber on Mechanical Properties and Toughness of Self-Compacting Concrete Exposed to High Temperatures[J]. AUT Journal of Civil Engineering, 2017, 2: 153-166.

[8] Zhang B, Cullen M, Kilpatrick, et al. Spalling of Heated High Performance Concrete Due to Thermal and Hygric Gradients[J]. Advances in Concrete Construction, 2016, 4(1): 1-14.

[9] Liu X, Ye G, De S, et al. On the Mechanism of Polypropylene Fibres in Preventing Fire Spalling in Self-compacting and High-performance Cement Paste[J]. Cement and Concrete Research, 2008, 38(4): 487-499.

[10] Persson B. Fire Resistance of Self-compacting Concrete, SCC[J]. Materials and Structures, 2004, 37(273): 575-584.

[11] Samson G, Phelipot-Mardelé A, Lanos, et al. A Review of Thermome-chanical Properties of Lightweight Concrete[J]. Magazine of Concrete Research, 2016, 69(4): 201-216.

[12] Liu Z H, Wang F, Deng Z P. Thermal Insulation Material Based on SiO2 Aerogel[J]. Construction and Building Materials, 2016, 122(2): 548-555.

[13] Noumowé A, Carré H, Daoud, et al. High-Strength Self-Compacting Concrete Exposed to Fire Test[J]. Journal of Materials in Civil Engineering, 2006, 18(6): 754-758.

[14] Serrano R, Cobo A, Prieto, et al. Analysis of Fire Resistance of Concrete with Polypropylene or Steel Fibers[J]. Construction and Building Materials, 2016, 122: 302-309.

[15] Sobia A Q, Hamidah M S, Azmi, et al. Elevated Temperature Resistance of Ultra-high-performance Fibre-reinforced Cementitious Composites[J]. Magazine of Concrete Research, 2016, 67(17): 923-937.

[16] Kim J H J, Mook Lim Y, Won, et al. Fire Resistant Behavior of Newly Developed Bottom-ash-based Cementitious Coating Applied Concrete Tunnel Lining under RABT Fire Loading[J]. Construction and Building Materials, 2010, 24(10): 1984-1994.

[17] Benk A, Coban A. Possibility of Producing Lightweight, Heat Insulating Bricks from Pumice and H₃PO₄- or NH₄NO₃-hardened Molasses Binder[J]. Ceramics International, 2012, 38(3): 2283-2293.

[18] Suvorov S A, Skurikhin V V. Vermiculite — A Promising Material for High-temperature Heat Insulators[J]. Refractories and Industrial Ceramics, 2003, 44(3): 186-193.

[19] Jia G, Li Z. Applications of Aerogel in Cement-based Thermal Insulation Materials: An Overview[J]. Magazine of Concrete Research, 2017, 70(16): 822-837.

[20] Lothenbach B, Winnefeld F, Alder, et al. Effect of Temperature on the Pore Solution, Microstructure and Hydration Products of Portland Cement Pastes[J]. Cement and Concrete Research, 2007, 37(4): 483-491.

[21] Ng S, Jelle B P, Stæhli T. Calcined Clays as Binder for Thermal Insulating and Structural Aerogel Incorporated Mortar[J]. Cement and Concrete Composites, 2016, 72: 213-221.

[22] Yao Y, Hu X X. Cooling Behavior and Residual Strength of Post-fire Concrete Filled Steel Tubular Columns[J]. Journal of Constructional Steel Research, 2015, 112: 282-292.

[23] Husem M. The Effects of High Temperature on Compressive and Flexural Strengths of Ordinary and High-performance Concrete[J]. Fire Safety Journal, 2006, 41(2): 155-163.

[24] AQSIQ, SAC. Fire Resistance Test for Elements of Buliding Construction—Alternative and Additional Procedures[S]. GB/T 26784-2011, 2001

[25] AQSIQ, SAC. Standard for Test Method of Concrete Physical and Mechanical Properties[S]. GB/T 50081-2016, 2019

[26] Huang D, Guo C, Zhang M, et al. Characteristics of Nanoporous Silica Aerogel under High Temperature from 950 °C to 1 200 °C[J]. Materials and Design, 2017, 129(1): 82-90.

[27] Heo Y, Lee G, Lee G. Effect of Elevated Temperatures on Chemical Properties, Microstructure and Carbonation of Cement Paste[J]. Journal of Ceramic Processing Research, 2016, 17(6): 648-652.

[28] Sahani A K, Samanta A K, Singha, et al. Influence of Mineral by-products on Compressive Strength and Microstructure of Concrete at High Temperature[J]. Advances in Concrete Construction, 2019, 4: 263-275.

[29] Bošnjak J, Sharma A, Grauf K. Mechanical Properties of Concrete with Steel and Polypropylene Fibres at Elevated Temperatures[J]. Fibers, 2019, 7(2): 1-13.

[30] Yan Z G, Shen Y Z. Experimental Investigation of Reinforced Concrete and Hybrid Fibre Reinforced Concrete Shield Tunnel Segments Subjected to Elevated Temperature[J]. Fire Safety Journal, 2015, 71(1): 86-99.

[31] Wang G, Zhang C. Study on the High-temperature Behavior and Rehydration Characteristics of Hardened Cement Paste[J]. Fire and Materials, 2015, 39(10): 741-750.

[32] Chung HW. Assessment and Classification of Damages in Reinforced Concrete Structures[J]. Concrete International, 1994, 16(3): 55-59.

[33] Botte W, Caspeele R. Post-cooling Properties of Concrete Exposed to Fire[J]. Fire Safety Journal, 2017, 92(5): 142-150.

[34] Tao J, Yuan Y, Taerwe, et al. Compressive Strength of Self-Compacting Concrete during High-Temperature Exposure[J]. Journal of Materials in Civil Engineering, 2010, 22(10): 1005-1011.

[35] Li Q, Yuan G, Shu Q. Effects of Heating/Cooling on Recovery of Strength and Carbonation Resistance of Fire-damaged Concrete[J]. Magazine of Concrete Research, 2014, 66(18): 925-936.

[36] Pietrak K, Winiewski T S. A Review of Models for Effective Thermal Conductivity of Composite Materials[J]. Journal of Power Technologies, 2015, 95(1): 14-24.

[37] Li Z, Cheng X. Aramid Fibers Reinforced Silica Aerogel Composites with Low Thermal Conductivity and Improved Mechanical Performance[J]. Composites Part A: Applied Science and Manufacturing, 2016, 84: 316-325.

[38] So H-S, Yi J-B, Khulgadai, et al. Properties of Strength and Pore Structure of Reactive Powder Concrete Exposed to High Temperature[J]. ACI Materials J., 2014, 111(3): 335-345.

[39] Yan X, Li H, Wong Y-L. Assessment and Repair of Fire-damaged High-strength Concrete: Strength and Durability[J]. Journal of Materials in Civil Engineering, 2007, 19(6): 462-469.

[40] Uysal M, Tanyildizi H. Estimation of Compressive Strength of Self Compacting Concrete Containing Polypropylene Fiber and Mineral Additives Exposed to High Temperature Using Artificial Neural Net-work[J]. Construction and Building Materials, 2012, 27(1): 404-414.

[41] De Fátima Júlio M, Soares A, Ilharco L M, et al. Aerogel-based Renders with Lightweight Aggregates: Correlation between Molecular/Pore Structure and Performance[J]. Construction and Building Materials, 2016, 124: 485-495.

[42] Ng S, Jelle B P, Sandberg L I C, et al. Experimental Investigations of Aerogel-incorporated Ultra-high Performance Concrete[J]. Construction and Building Materials, 2015, 77: 307-316.

[43] Real S, Bogas J A, Gomes, et al. Thermal Conductivity of Structural Lightweight Aggregate Concrete[J]. Magazine of Concrete Research, 2016, 68(15): 798-808.