With the development of steel bridge engineering science, PVA fiber cement-based composite materials are gradually being explored and applied. Because of its high ductility and toughness, it has received extensive attention from academia and industry. Cement-based composite materials are essentially made of cement-related raw materials, which are mixed with various other materials to form composite materials. Incorporating Nano-SiO2 into it can effectively improve the structural performance and durability of cement-based composite materials. Therefore, the purpose of this paper is to study the crack resistance and toughness mechanism of Nano-SiO2 reinforced PVA fiber cement-based composites in steel bridge engineering. This paper first determined the design plan of the mix ratio of the Nano-SiO2 PVA fiber cement-based composite material, and then used the composite beam composed of PVA fiber concrete and existing concrete as the experimental object.  The test data shows that when the amount of hydrophilic nanopowder SiO2 reaches 1%, the compressive strength of the mortar at the second and third day of age is increased. At this time, the higher the content of hydrophilic nanopowder SiO2, the higher its compressive and flexural strength. However, when the content is greater than 1.0%, the content of hydrophilic nano-powder SiO2 has no great influence on the improvement of its compressive strength.

Edrise Zeinalli. Crack Resistance and Toughening Mechanism of Nano-SiO2 Reinforced PVA Fiber Cement-based Composites in Steel Bridge Engineering. International Journal of Engineering Technology and Construction (2022), Vol. 3, Issue 3: 20-37. https://doi.org/10.38007/IJETC.2022.030302.

[1] Zhang Z , Zhang Q . Matrix Tailoring of Engineered Cementitious Composites (ECC) with non-oil-coated, low tensile strength PVA fiber. Construction & Building Materials, 2018, 161(FEB.10):420-431.

[2] Shaikh F , Patel A . Flexural behavior of hybrid PVA fiber and AR-Glass textile reinforced geopolymer composites. Fibers, 2018, 6(1):2-2. https://doi.org/10.3390/fib6010002

[3] Liu T Y , Zhang P , Wang J , et al. Compressive Strength Prediction of PVA Fiber- Reinforced Cementitious Composites Containing Nano-SiO2 Using BP Neural Network. Materials, 2020, 13(3):521. https://doi.org/10.3390/ma13030521

[4] Ito H , Watanabe K , Todoroki S , et al. Study on Performance of PVA Fiber Reinforced Concrete Exposed for 10 Years to Seawater Spray. Journal of Advanced Concrete Technology, 2018, 16(3):159-169. https://doi.org/10.3151/jact.16.159

[5] Yoon H K , Kim S W , Jang Y I , et al. Flexural Behavior Characteristics of Steel Tube Filled with PVA Fiber-reinforced Cement Composites (FRCCs) Incorporating Recycled Materials. Journal of the Korea Concrete Institute, 2020, 32(3):275-283. https://doi.org/10.4334/JKCI.2020.32.3.275

[6] Souza L D , Alavarse A C , Vinci M , et al. The Synergistic Effect of Polymer Composition, Solvent Volatility, and Collector Distance on Pullulan and PVA Fiber Production by Rotary Jet Spinning. Fibers and Polymers, 2021, 22(4):1-15. https://doi.org/10.1007/s12221-021-0392-4

[7] Chen C ,  Li W ,  D  Yang, et al. Study on Autoclave Expansion Deformation of MgO-Admixed Cement-Based Materials. Emerging Materials Research, 2017, 6(2):1-7. https://doi.org/10.1680/jemmr.16.00090

[8] Wang Y , Zhi Q T , Zhao C , et al. Reflection-Based Thin-Core Modal Interferometry Optical Fiber Functionalized With PAA-PBA/PVA for Glucose Detection Under Physiological pH. Journal of Lightwave Technology, 2018, PP(99):1-1.

[9]Wakeel S A ,  J  Němeek,  Li L , et al. The effect of introducing nanoparticles on the fracture toughness of well cement paste. International Journal of Greenhouse Gas Control, 2020, 84(2019):147-153. https://doi.org/10.1016/j.ijggc.2019.03.009

[10] Selim A , Toth A J , Haaz E , et al. Comparison of Single and Double-Network PVA Pervaporation Performance: Effect of Operating Temperature. Periodica Polytechnica Chemical Engineering, 2020, 64(3):377–383. https://doi.org/10.3311/PPch.15214

[11] Laura, M, Sanchez, et al. Effect of PAA-coated magnetic nanoparticles on the performance of PVA-based hydrogels developed to be used as environmental remediation devices. Journal of Nanoparticle Research, 2019, 21(3):1-16.

[12] Pouran, Samimi, Sara, et al. Effect of Delayed Light-Curing Through a Zirconia Disc on Microhardness and Fracture Toughness of Two Types of Dual-Cure Cement.. Journal of dentistry (Tehran, Iran), 2018, 15(6):339-350. https://doi.org/10.18502/jdt.v15i6.326

[13] Xie T , Ali M , Visintin P , et al. Partial Interaction Model of Flexural Behavior of PVA Fiber-Reinforced Concrete Beams with GFRP Bars. Journal of Composites for Construction, 2018, 22(5):04018043.1-04018043.11.

[14] J Yu, Zhai T , Liang X , et al. Fluidity and Mechanical Properties of Steel-PVA Fiber Reinforced Concrete. Jianzhu Cailiao Xuebao/Journal of Building Materials, 2018, 21(3):402-407.

[15] Khanikar T , Singh V K . PANI-PVA composite film coated optical fiber probe as a stable and highly sensitive pH sensor. Optical Materials, 2019, 88(FEB.):244-251. https://doi.org/10.1016/j.optmat.2018.11.044

[16] Ahmad H , Aidit S N , Tiu Z C , et al. Application of MoWS_2-rGO/PVA thin film as all-fiber pulse and amplitude modulators in the O-band region. Optical fiber technology, 2019, 48(MAR.):1-6. https://doi.org/10.1016/j.yofte.2018.12.011

[17] Luming, Yang, Jinwei, et al. Influence of collagen hydrolysate components on fabrication of collagen/PVA composite fiber:. Textile Research Journal, 2019, 90(9-10):1141-1148. https://doi.org/10.1177/0040517519885020

[18] Li X ,  Lv X ,  Wang W , et al. Crack resistance of waste cooking oil modified cement stabilized macadam. Journal of Cleaner Production, 2020, 243(Jan.10):118525.1-118525.11.

[19] Zhao Y ,  Yang X ,  Zhang Q , et al. Crack Resistance and Mechanical Properties of Polyvinyl Alcohol Fiber-Reinforced Cement-Stabilized Macadam Base. Advances in Civil Engineering, 2020, 2020(1):1-15. https://doi.org/10.1155/2020/6564076

[20] Mouro C , Simes M , Gouveia I C . Emulsion Electrospun Fiber Mats of PCL/PVA/Chitosan and Eugenol for Wound Dressing Applications. Advances in Polymer Technology, 2019, 2019(1):1-11. https://doi.org/10.1155/2019/9859506

[21] Hu Q , Li M , Li P , et al. Dual-wavelength passively mode-locked Yb-doped fiber laser based on a $ext{SnSe}_2$-PVA saturable absorber. IEEE Photonics Journal, 2019, PP(99):1-1.

[22] Rui Z , Xu X , Bing C , et al. Fabrication of high-performance PVA/PAN composite pervaporation membranes crosslinked by PMDA for wastewater desalination. Petroleum Science, 2018, 15(01):1-11.

[23] Kostagiannakopoulou C ,  Tsilimigkra X ,  Sotiriadis G , et al. Synergy effect of carbon nano-fillers on the fracture toughness of structural composites. Composites Part B Engineering, 2017, 129(nov.):18-25.

[24] Zhang P , Li Q F , Wang J , et al. Effect of PVA fiber on durability of cementitious composite containing nano-SiO2. Nanotechnology Reviews, 2019, 8(1):116-127. https://doi.org/10.1515/ntrev-2019-0011

[25] Ling Y , Zhang P , Wang J , et al. Bending resistance of PVA fiber reinforced cementitious composites containing nano-SiO2. Nanotechnology Reviews, 2019, 8(1):690-698. https://doi.org/10.1515/ntrev-2019-0060