Synergistic Effect of Multi-Scale MgO Expansion Agent and SAP on Mechanical and Shrinkage Properties of UHPC

Abstract

Abstract: Due to its low water-to-binder ratio and high content of cementitious materials, ultra-high performance concrete(UHPC) produces large autogenous shrinkage at early age, which easily causes shrinkage cracking of UHPC. Therefore, multi-scale MgO expansion agent and super absorbent polymer (SAP) internal curing material were mixed to solve this problem. The effects of multi-scale MgO expansion agent and internal curing material on mechanical, shrinkage and hydration characteristics of steam-free UHPC were investigated, and then the synergistic mechanism of mixing multi-scale expansion agent and internal curing material was revealed by SEM, XRD, MIP and TG-DTG microscopic methods. The results show that mixing multi-scale MgO expansion agent is more conducive to the development of mechanical properties of UHPC than single-scale MgO and nano MgO, and at the same time provides a stable expansion source for the whole process of hydration of UHPC system. On the basis of adding muti-scale expansion agent,the introduction of SAP can improve the working performance of UHPC, while further reducing the autogenous shrinkage of UHPC at early age. The research results can provide data support and theoretical guidance for solving the problem of large autogenous shrinkage in the early stage of UHPC.

Key words: ultra-high performance concrete, expansion agent, internal curing material, autogenous shrinkage, strength, synergistic effect

CLC Number:

TU528

WEI Yaping, LI Shaocheng, WANG Youzhi, TIAN Changjin. Synergistic Effect of Multi-Scale MgO Expansion Agent and SAP on Mechanical and Shrinkage Properties of UHPC[J]. BULLETIN OF THE CHINESE CERAMIC SOCIETY, 2023, 42(9): 3154-3165.

References

[1] MENG W N, VALIPOUR M, KHAYAT K H. Optimization and performance of cost-effective ultra-high performance concrete[J]. Materials and Structures, 2016, 50(1): 1-16.
[2] TENG L, MENG W N, KHAYAT K H. Rheology control of ultra-high-performance concrete made with different fiber contents[J]. Cement and Concrete Research, 2020, 138: 106222.
[3] JUSTS J, WYRZYKOWSKI M, BAJARE D, et al. Internal curing by superabsorbent polymers in ultra-high performance concrete[J]. Cement and Concrete Research, 2015, 76: 82-90.
[4] WU Z M, SHI C J, KHAYAT K H. Investigation of mechanical properties and shrinkage of ultra-high performance concrete: influence of steel fiber content and shape[J]. Composites Part B: Engineering, 2019, 174: 107021.
[5] TEMIZ H, KANTARC F, INCEER M E. Influence of blast-furnace slag on behaviour of dolomite used as a raw material of MgO-type expansive agent[J]. Construction and Building Materials, 2015, 94(30): 528-535.
[6] LI M, LIU J P, TIAN Q, et al. Efficacy of internal curing combined with expansive agent in mitigating shrinkage deformation of concrete under variable temperature condition[J]. Construction and Building Materials, 2017, 145: 354-360.
[7] CHEN X, YANG H Q, LI W W. Factors analysis on autogenous volume deformation of MgO concrete and early thermal cracking evaluation[J]. Construction and Building Materials, 2016, 118: 276-285.
[8] THOMAS J J, MUSSO S, PRESTINI I. Kinetics and activation energy of magnesium oxide hydration[J]. Journal of the American Ceramic Society, 2014, 97(1): 275-282.
[9] LI H, TIAN Q, ZHAO H T, et al. Temperature sensitivity of MgO expansive agent and its application in temperature crack mitigation in shiplock mass concrete[J]. Construction and Building Materials, 2018, 170: 613-618.
[10] CAO F Z, YAN P Y. The influence of the hydration procedure of MgO expansive agent on the expansive behavior of shrinkage-compensating mortar[J]. Construction and Building Materials, 2019, 202: 162-168.
[11] LIU S X. Effect of nano Al₂O₃ and MgO on abrasion resistance and mechanism of ultra-high performance concrete[J]. Surface Technology, 2018, 47(10): 123-130.
[12] YE Q, YU S H, ZHANG Z N, et al. Effects of nano-MgO on expansion and strength of hardened cement pastes[J]. Journal of Building Materials, 2017, 20(5): 765-769.
[13] GAO P W, LU X L, TANG M S. Shrinkage and expansive strain of concrete with fly ash and expansive agent[J]. Journal of Wuhan University of Technology-Mater Sci Ed, 2009, 24(1): 150-153.
[14] POLAT R, DEMIRBOĞA R, KHUSHEFATI W H. Effects of nano and micro size of CaO and MgO, nano-clay and expanded perlite aggregate on the autogenous shrinkage of mortar[J]. Construction and Building Materials, 2015, 81: 268-275.
[15] POLAT R, DEMIRBOĞA R, KARAGÖL F. The effect of nano-MgO on the setting time, autogenous shrinkage, microstructure and mechanical properties of high performance cement paste and mortar[J]. Construction and Building Materials, 2017, 156: 208-218.
[16] HOU P K, CAI Y M, CHENG X, et al. Effects of the hydration reactivity of ultrafine magnesium oxide on cement-based materials[J]. Magazine of Concrete Research, 2017, 69(22): 1135-1145.
[17] MORADPOUR R, TAHERI-NASSAJ E, PARHIZKAR T, et al. The effects of nanoscale expansive agents on the mechanical properties of non-shrink cement-based composites: the influence of nano-MgO addition[J]. Composites Part B: Engineering, 2013, 55: 193-202.
[18] 胡玉庆. 内养护与氧化镁膨胀剂复合对混凝土性能的影响[D]. 济南: 山东大学, 2018.
HU Y Q. Effect of internal curing and magnesium oxide expansive agent on the performance of concrete[D]. Jinan: Shandong University, 2018 (in Chinese).
[19] MO L W, DENG M, TANG M S, et al. MgO expansive cement and concrete in China: past, present and future[J]. Cement and Concrete Research, 2014, 57: 1-12.
[20] ZHENG X G, HAN M, LIU L L. Effect of superabsorbent polymer on the mechanical performance and microstructure of concrete[J]. Materials, 2021, 14(12): 3232.
[21] JEON S I, JUNG D H, NAM J H, et al. Strength development and shrinkage of superabsorbent polymer concrete with calcium sulfoaluminate clinker and shrinkage reducing admixture[J]. Sustainability, 2021, 13(15): 8362.
[22] 刘路明, 方志, 黄政宇, 等. 膨胀剂与内养剂对超高性能混凝土性能的影响[J]. 硅酸盐学报, 2020, 48(11): 1706-1715.
LIU L M, FANG Z, HUANG Z Y, et al. Effects of expansive agent and super-absorbent polymer on performance of ultra-high performance concrete[J]. Journal of the Chinese Ceramic Society, 2020, 48(11): 1706-1715 (in Chinese).
[23] YOO D Y, KIM S, KIM M J. Comparative shrinkage behavior of ultra-high-performance fiber-reinforced concrete under ambient and heat curing conditions[J]. Construction and Building Materials, 2018, 162: 406-419.
[24] 江星. 氧化镁膨胀剂对碱矿渣砂浆收缩行为的影响[D]. 重庆: 重庆大学, 2017.
JIANG X. Effect of magnesium oxide on shrinkage behavior of alkali-activated slag mortars[D]. Chongqing: Chongqing University, 2017 (in Chinese).
[25] SANCHEZ F, SOBOLEV K. Nanotechnology in concrete: a review[J]. Construction and Building Materials, 2010, 24(11): 2060-2071.
[26] 周磊, 王有志, 章国宁, 等. 纳米MgO对水泥基材料性能影响研究进展[J]. 混凝土与水泥制品, 2019(5): 13-18.
ZHOU L, WANG Y Z, ZHANG G N, et al. Research progress of the influence of nano-MgO on performance of cement-based materials[J]. China Concrete and Cement Products, 2019(5): 13-18 (in Chinese).
[27] 张雪. MgO和纳米MgO高性能混凝土微观表征及早龄期性能研究[D]. 济南: 山东大学, 2019.
ZHANG X. Microscopic characterization and early age performance of MgO and nano-MgO high performance concrete[D]. Jinan: Shandong University, 2019 (in Chinese).
[28] YOO D Y, SHIN H O, LEE J Y, et al. Enhancing cracking resistance of ultra-high-performance concrete slabs using steel fibres[J]. Magazine of Concrete Research, 2015, 67(10): 487-495.
[29] ZHANG M H, TAM C T, LEOW M P. Effect of water-to-cementitious materials ratio and silica fume on the autogenous shrinkage of concrete[J]. Cement and Concrete Research, 2003, 33(10): 1687-1694.
[30] TAM C M, TAM V W Y, NG K M. Assessing drying shrinkage and water permeability of reactive powder concrete produced in [J]. Construction and Building Materials, 2012, 26(1): 79-89.
[31] TAM V W Y, KOTRAYOTHAR D, XIAO J Z. Long-term deformation behaviour of recycled aggregate concrete[J]. Construction and Building Materials, 2015, 100: 262-272.
[32] HUA C, ACKER P, EHRLACHER A. Analyses and models of the autogenous shrinkage of hardening cement paste[J]. Cement and Concrete Research, 1995, 25(7): 1457-1468.
[33] 胡功球. 不同养护条件下超高性能混凝土(UHPC)的收缩性能研究[D]. 长沙: 湖南大学, 2015.
HU G Q. Research on the shrinkage performance of ultra high performance concrete under different curing condition[D]. Changsha: Hunan University, 2015 (in Chinese).
[34] 邓敏, 崔雪华, 刘元湛, 等. 水泥中氧化镁的膨胀机理[J]. 南京工业大学学报(自然科学版), 1990, 12(4): 1-11.
DENG M, CUI X H, LIU Y Z, et al. Expansive mechanism of magnesia as an additive of cement[J]. Journal of Nanjing University of Technology (Natural Science Edition), 1990, 12(4): 1-11 (in Chinese).
[35] GHOFRANI R, PLACK H. CaO-and/or MgO-swelling cements: a key for providing a better annular sealing?[C]//SPE/IADC Drilling Conference. Amsterdam, Netherlands. Society of Petroleum Engineers, 1993.
[36] NARJES J, RICA G M, PAL S. Nanosized magnesium oxide with engineered expansive property for enhanced cement-system performance[J]. SPE Journal, 2017, 22(5): 1681-1689.
[37] 黄明喜. 基于含镁尾矿制备氧化镁材料及其性能研究[D]. 南京: 南京航空航天大学, 2012.
HUANG M X. Preparation of MgO material from magnesite tailings and its properties[D]. Nanjing: Nanjing University of Aeronautics and Astronautics, 2012 (in Chinese).
[38] 周文静. 低收缩超高性能混凝土的设计制备及其减缩机理研究[D]. 南京: 东南大学, 2019.
ZHOU W J. Design and preparation of low shrinkage ultra-high performance concrete and study on shrinkage reduction mechanism[D]. Nanjing: Southeast University, 2019 (in Chinese).
[39] 李思琪. MgO膨胀剂掺量对补偿收缩水泥净浆微观结构的影响规律研究[D]. 泰安: 山东农业大学, 2021.
LI S Q. Research on influence of MgO expansive agent dosage on microscopic structure of shrinkage compensating cement paste[D]. Taian: Shandong Agricultural University, 2021 (in Chinese).
[40] 刘剑辉. SAP与FLWA在超高性能混凝土中的内养护作用[D]. 长沙: 湖南大学, 2019.
LIU J H. Internal curing of SAP and FLWA in ultra-high performance concrete[D]. Changsha: Hunan University, 2019 (in Chinese).