Influence of Different Alkali Sulfates on Shrinkage Properties of Cement-based Materials with Different Mineral Compositions

LI Yang; JIANG Ke; ZHANG Zhen-zhong; HUANG Ming-hui

doi:10.11988/ckyyb.20201023

PDF(1354 KB)

Journal of Changjiang River Scientific Research Institute ›› 2022, Vol. 39 ›› Issue (1) : 139-145. DOI: 10.11988/ckyyb.20201023

HYDRAULIC STRUCTURE AND MATERIAL

Influence of Different Alkali Sulfates on Shrinkage Properties of Cement-based Materials with Different Mineral Compositions

LI Yang^1,2, JIANG Ke¹, ZHANG Zhen-zhong¹, HUANG Ming-hui³

Author information +

History +

Abstract

In this study, Na₂SO₄ (Na alkali) and K₂SO₄ (K alkali) were added to adjust the total alkali content of low-heat Portland cement (LHPC), medium-heat Portland cement (MMPC) and ordinary Portland cement (OPC) to 0.8% and 1.2%. The effects of different alkali sulfates on autogenous shrinkage and dry shrinkage of cement-based materials with different mineral compositions were investigated. The mechanism of different alkali sulfates affecting the autogenous shrinkage and drying shrinkage of different cement-based materials was also revealed via microcalorimetry, mercury intrusion porosimetry (MIP) and nuclear magnetic resonance (NMR). Results indicate that 1) alkali sulfates promote the shrinkage of different cement-based materials. At the same content of alkali sulfate, LHPC has a low autogenous shrinkage rate and OPC has a high autogenous shrinkage rate; but as for drying shrinkage, OPC has the smallest rate and MHPC has the largest rate. 2) In different cement-based materials, the promotion effect of K alkali is higher than that of Na alkali and such promotion effect intensifies with the rise of alkali content. When alkali content is 0.8%, the promotion effect of K alkali is more than 1.1 times that of Na alkali; when alkali content reaches 1.2%, the promotion effect of K alkali is over 1.3 times that of Na alkali. Microscopic test also manifested a larger promotion effect of K alkali than Na alkali: K alkali promotes the hydration of cement, enhances the content of pores with a size smaller than 50 nm, and is related to the transfer of Al atoms into C-S-H chain.

Key words

alkali sulfates / cement-based material / shrinkage property / hydration process / pore structure / aluminum atom

Cite this article

EndNote

Ris (Procite)

Bibtex

Download Citations

LI Yang, JIANG Ke, ZHANG Zhen-zhong, HUANG Ming-hui. Influence of Different Alkali Sulfates on Shrinkage Properties of Cement-based Materials with Different Mineral Compositions[J]. Journal of Changjiang River Scientific Research Institute. 2022, 39(1): 139-145 https://doi.org/10.11988/ckyyb.20201023

References

[1] MEHTA P K. Concrete Technology at the Crossroads: Problems and Opportunities[C]//Proceedings of the Mohan Malhotra Symposium on Concrete Technology: Past, Present, and Future. Detroit, November 3, 1993: 1-30.
[2] 理查德·W·伯罗斯,廉慧珍,覃维祖,等. 混凝土的可见与不可见裂缝[M]. 北京:中国水利水电出版社, 2013.
[3] WANG L, YANG H Q, ZHOU S H, et al. Mechanical Properties, Long-term Hydration Heat, Shrinkage Behavior and Crack Resistance of Dam Concrete Designed with Low Heat Portland (LHP) Cement and Fly Ash[J]. Construction and Building Material, 2018, 187:1073-1091.
[4] MOBILI A A, TELESCA B A, MARROCCOLI B M, et al. Calcium Sulfoaluminate and Alkali-activated Fly Ash Cements as Alternative to Portland Cement: Study on Chemical, Physical-Mechanical, and Durability Properties of Mortars with the Same Strength Class[J]. Construction and Building Materials, 2020, 246:118436.
[5] HE Z, LI Z J. Influence of Alkali on Restrained Shrinkage Behavior of Cement-based Materials[J]. Cement and Concrete Research, 2005, 35(3): 457-463.
[6] 陈美祝. 水泥基材料组分对早期水化及收缩开裂影响的研究[D]. 武汉:武汉大学, 2004.
[7] 肖忠明. 现代混凝土开裂的原因之综述[J]. 水泥工程, 2015(1): 72-78.
[8] 何真,李洋,蔡新华,等. Na⁺和K⁺对水泥基材料早期收缩性能的影响[J]. 水利学报, 2016,47(11): 1345-1351.
[9] 李洋,蒋科,黄明辉,等. Na碱和K碱对低热水泥收缩性能的影响[J]. 长江科学院院报, 2020, 37(3):125-130.
[10] MOTA B, MATSCHEI T, SCRIVENER K. The Influence of Sodium Salts and Gypsum on Alite Hydration[J]. Cement and Concrete Research, 2015, 75: 53-65.
[11] 曹园章, 郭丽萍, 薛晓丽. NaCl和Na₂SO₄对水泥水化机理的影响[J]. 东南大学学报:自然科学版, 2019,49(4):712-719.
[12] HAGHTALAB A, BADIZAD M H. Solubility of Gypsum in Aqueous NaCl + K₂SO₄ Solution Using Calcium Ion Selective Electrode-Investigation of Ionic Interactions[J]. Fluid Phase Equilibria, 2016, 409:341-353.
[13] 钱觉时, 韦迎春, 邓铃夕,等. 硅酸盐水泥中硫酸盐类型与作用[J]. 硅酸盐学报, 2014, 42(2):169-177.
[14] WANG L,ZHOU S H,SHI Y,et al.Effect of Silica Fume and PVA Fiber on the Abrasion Resistance and Volume Stability of Concrete[J].Composites, 2017,130:28-37.
[15] YANG K, ZHONG M, MAGEE B, et al. Investigation of Effects of Portland Cement Fineness and Alkali Content on Concrete Plastic Shrinkage Cracking[J]. Construction and Building Materials, 2017, 144: 279-290.
[16] SCRIVENER K L, JUILLAND P, MONTEIRO P J M. Advances in Understanding Hydration of Portland Cement[J]. Cement & Concrete Research, 2015, 78:38-56.
[17] HÉLÈNE M, GARRAULT S, REGNAUD L, et al. Mechanisms and Parameters Controlling the Tricalcium Aluminate Reactivity in the Presence of Gypsum[J]. Cement and Concrete Research, 2007, 37(10):1418-1426.
[18] MOTA B, MATSCHEI T, SCRIVENER K. The Influence of Sodium Salts and Gypsum on Alite Hydration[J]. Cement and Concrete Research, 2015, 75:53-65.
[19] PUSTOVGAR E, MISHRA R K, PALACIOS M, et al. Influence of Aluminates on the Hydration Kinetics of Tricalcium Silicate[J]. Cement and Concrete Research, 2017, 100:245-262.
[20] THOMAS J J, ALLEN A J, JENNINGS H M. Structural Changes to the Calcium-Silicate-Hydrate Gel Phase of Hydrated Cement with Age, Drying, and Resaturation[J]. Journal of the American Ceramic Society, 2008,91(10):3362-3369.
[21] MEHTA P K, MONTEIRO P J M. Concrete: Microstructure, Properties, and Materials(Edition 3)[M]. New York: McGraw-Hill Professional, 2006.
[22] ANDERSEN M D, JAKOBSEN H J, SKIBSTED J. A New Aluminium-Hydrate Species in Hydrated Portland Cements Characterized by ²⁷Al and ²⁹Si MAS NMR Spectroscopy[J]. Cement and Concrete Research, 2006, 36(1):3-17.
[23] PAUL G, BOCCALERI E, BUZZI L, et al. Friedel's Salt Formation in Sulfoaluminate Cements: A Combined XRD and ²⁷Al MAS NMR Study[J]. Cement and Concrete Research, 2015, 67:93-102.
[24] J·本斯迪德, P·巴恩斯. 水泥的结构和性能[M]. 2版.廖欣译.北京:化学工业出版社, 2008.
[25] WANG L, GUO F X ,LIN Y Q, et al. Comparison between the Effects of Phosphorous Slag and Fly Ash on the C-S-H Structure, Long-term Hydration Heat and Volume Deformation of Cement-based Materials[J]. Construction & Building Materials, 2020, 250:118807.
[26] 李洋, 何真, 郭文康, 等. 碱对低热水泥早期水化进程和微结构的影响[J]. 建筑材料学报, 2018, 21(4):549-555.
[27] PAGLIA C, WOMBACHER F, BÖHNI H. The Influence of Alkali-free and Alkaline Shotcrete Accelerators within Cement Systems: Influence of the Temperature on the Sulfate Attack Mechanisms and Damage[J]. Cement and Concrete Research, 2003, 33(3):387-395.