Frost Resistance of Magnesium Oxychloride Cement Mortar Added with Highland Barley Straw Ash

Abstract

In order to study the influence of highland barley straw ash (HBSA) prepared under certain conditions on the durability of magnesium oxychloride cement mortar (MOCM) under freeze-thaw damage, rapid freeze-thaw cycle tests were carried out firstly. The relative mass evaluation parameters and the relative compressive strength evaluation parameters, which represent the degradation of freeze-thaw resistance, were used as the indices to study the degradation rule of MOCM. Secondly, nuclear magnetic resonance (NMR) tests were carried out on MOCM under different freeze-thaw cycles to analyze the pore diameter changes in the freeze-thaw process. The microstructure of MOCM was tested by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and scanning electron microscopy (SEM), and then the effect mechanism of HBSA on the anti-freezing performance of MOCM was revealed. Finally, the two-parameter Weibull distribution function was used to analyze the reliability of durability degradation of MOCM added with HBSA under freeze-thaw cycles. The specific conclusions are as follows: With the increase of HBSA’s addition, the freeze-thaw resistance of MOCM increase firstly and then decrease. When the addition of HBSA is 10%, the decay rate of relative mass evaluation parameters and relative compressive strength evaluation parameters is the slowest, and the frost resistance is the best. The proportion of harmful pores and more harmful pores in MOCM added with 10% HBSA decreases by 25.11% and 21.34%, compared with that without HBSA before and after freeze-thaw cycles. A lot of magnesium silicate hydrate (M-S-H) gels are generated in MOCM with HBSA content of 10%, which fills part of the pores, so that the proportion of harmful pores and more harmful pores is the lowest. The Weibull function can be effectively applied to the reliability analysis of the freeze-thaw cycle of MOCM added with HBSA, and the theoretical results are in good agreement with the experimental results.

Keywords

magnesium oxychloride cement / highland barley straw ash / freeze-thaw resistance / pore diameter distribution / microstructure / reliability

References

[1] Wasim M, Ngo T D, Abid M. Investigation of Long-term Corrosion Resistance of Reinforced Concrete Structures Constructed with Various Types of Concretes in Marine and Various Climate Environments[J]. Constr. Build. Mater., 2020, 237: 117 701.

[2] Huang Q, Li Y, Chang C G, et al. The Salt Attack Performance of Magnesium Oxychloride Cement Exposure to Three Kinds of Brines[J]. J. Wuhan Univ. Technol.-Mater. Sci. Ed., 2020, 35(20): 155-166.

[3] Chong L L, Yang J M, Xu Z Z, et al. Freezing and Thawing Resistance of MKPC Paste under Different Corrosion Solutions[J]. Constr. Build. Mater., 2019, 212: 663-674.

[4] Gong W, Wang N, Zhang N, et al. Water Resistance and a Comprehensive Evaluation Model of Magnesium Oxychloride Cement Concrete Based on Taguchi and Entropy Weight Method[J]. Constr. Build. Mater., 2020, 260: 119 817.

[5] Feng C F, Wang F Z, Liu P, et al. Photocatalytic Activity of Porous Magnesium Oxychloride Cement Combined with AC/TiO₂ Composites[J]. J. Wuhan Univ. Technol.-Mater. Sci. Ed., 2017, 32(03): 591-597.

[6] Guo Y Y, Zhang Y X, Soe K, et al. Recent Development in Magnesium Oxychloride Cement[J]. Struct. Concrete, 2018, 19(5): 1 290-1 300.

[7] Kastiukas G, Zhou X M, Neyazi B, et al. Sustainable Calcination of Magnesium Hydroxide for Magnesium Oxychloride Cement Production[J]. J. Mater. Civil Eng., 2019, 31(7): 04 019 110.1-04 019 110.9.

[8] Kan L L, Zhang L, Shi H S. Hydration Kinetics of Municipal Solid Wastes Incineration (MSWI) Fly Ash-Cement[J]. J. Wuhan Univ. Technol.-Mater. Sci. Ed., 2019, 34(03): 596-603.

[9] He Z H, Qian C X, Du S G, et al. Nanoindentation Characteristics of Cement Paste and Interfacial Transition Zone in Mortar with Rice Husk Ash[J]. J. Wuhan Univ. Technol.-Mater. Sci. Ed., 2017, 32(02): 417-421.

[10] Biricik H, Aköz F, Türker F, et al. Resistance to Magnesium Sulfate and Sodium Sulfate Attack of Mortars Containing Wheat Straw Ash[J]. Cem. Concr. Res., 2000, 30(8): 1 189-1 197.

[11] Guo Y Y, Zhang Y X, Soe K, et al. Effect of Fly Ash on Mechanical Properties of Magnesium Oxychloride Cement under Water Attack[J]. Struct. Concrete, 2020, 21(3): 1 181-1 199.

[12] Chau C K, Chan J, Li Z J. Influences of Fly Ash on Magnesium Oxychloride Mortar[J]. Cem. Concr. Compos., 2009, 31(4): 250-254.

[13] Gomes C M, Garry A L, Freitas E, et al. Effects of Rice Husk Silica on Microstructure and Mechanical Properties of Magnesium-oxychloride Fiber Cement (MOFC)[J]. Constr. Build. Mater., 2020, 241: 118 022.

[14] Qudoos A, Kakar E, Rehman A, et al. Influence of Milling Techniques on the Performance of Wheat Straw Ash in Cement Composites[J]. Appl. Sci., 2020, 10(10): 3 511

[15] Zhang Q, Li Y Z, Xu L, et al. Bond Strength and Corrosion Behavior of Rebar Embedded in Straw Ash Concrete[J]. Constr. Build. Mater., 2019, 205: 21-30.

[16] Al-Akhras N M. Durability of Wheat Straw Ash Concrete Exposed to Freeze-thaw Damage[J]. P. I. Civil Eng.-Constr. Mater., 2011, 164(4): 79-86.

[17] Mohammed O, Sun J, Xu B. Highland Barley: Chemical Composition, Bioactive Compounds, Health Effects, and Applications[J]. Food Res. Int., 2021, 140: 110 065.

[18] Guo T L, Horvath C, Chen L, et al. Understanding the Nutrient Composition and Nutritional Functions of Highland Barley (Qingke): A Review[J]. Trends Food Sci. Tech., 2020, 103: 109-117.

[19] Li H C, Xu G Y. Research on Chemical Composition and Fiber Morphology of Barley Straw[J]. Biomass Chem. Eng., 2010, 44(02): 40-42.

[20] Sonat C, Unluer C. Development of Magnesium-silicate-hydrate (M-S-H) Cement with Rice Husk Ash[J]. J. Clean. Prod., 2019, 211: 787-803.

[21] Ellina B, Barbara L, Christophe C, et al. Characterization of Magnesium Silicate Hydrate (M-S-H) [J]. Cem. Concr. Res., 2018, 116: 309-330.

[22] Nied D, Kasper E R, Emilie L, et al. Properties of Magnesium Silicate Hydrates (M-S-H) [J]. Cem. Concr. Res., 2016, 79: 323-332.

[23] Standardization Administration of China. Pozzolanic Materials Used for Cement Production[S]. GB/T 2847-2005, 2005

[24] Ministry of Housing and Urban-Rural Development of the People’s Republic of China. Natural Pozzolanic Materials Used for Cement Mortar and Concrete[S]. JG/T 315–2011, 2011

[25] Wang P H, Qiao H X, Chen K F, et al. Life Prediction and Long-Term Durability of Coated Steel Bars in Magnesium Oxychloride Concrete[J]. KSCE J. Civ. Eng., 2020, 24: 2 120-2 131.

[26] Ministry of Construction of the People’s Republic of China. Standard for Test Method of Basic Properties of Construction Motor[S]. JGJ/T 70, 2009

[27] Zhang J Z, Bian F, Zhang Y R, et al. Effect of Pore Structures on Gas Permeability and Chloride Diffusivity of Concrete[J]. Constr. Build. Mater., 2018, 163: 402-413.

[28] Wang Y, Yuan Q, Deng D H, et al. Measuring the Pore Structure of Cement Asphalt Mortar by Nuclear Magnetic Resonance[J]. Constr. Build. Mater., 2017, 137: 450-458.

[29] Wang J B, Liu M L, Wang Y G, et al. Synergistic Effects of Nano-silica and Fly Ash on Properties of Cement-based Composites[J]. Constr. Build. Mater., 2020, 262: 120 737.

[30] Ling M H, Hu X W. Optimal Design of Simple Step-stress Accelerated Life Tests for One-shot Devices under Weibull Distributions[J]. Reliab. Syst. Safe., 2020, 193: 106 630.1-106 630.10.

[31] Ma K L, Li S J, Long G C, et al. Performance Evolution and Damage Constitutive Model of Thin Layer SCC under the Coupling Effect of Freeze-Thaw Cycles and Load[J]. J. Mater. Civil Eng., 2020, 32(6): 04 020 147.1-04 020 147.11.