1. School of Civil Engineering, Central South University, Changsha 410075, China 2. Magnel Laboratory for Concrete Research, Department of Structural Engineering, Ghent University, Ghent 9052, Belgium 3. National Engineering Laboratory for High Speed Railway Construction, Central South University, Changsha 410075, China
Superabsorbent Polymer (SAP) has emerged as a topic of considerable interest in recent years. The present study systematically and quantitively investigated the effect of SAP on hydration, autogenous shrinkage, mechanical properties, and microstructure of cement mortars. Influences of SAP on hydration heat and autogenous shrinkage were studied by utilizing TAM AIR technology and a non-contact autogenous shrinkage test method. Scanning Electron Microscope (SEM) was employed to assess the microstructure evolution. Although SAP decreased the peak rate of hydration heat and retarded the hydration, it significantly increased the cumulative heat, indicating SAP helps promote the hydration. Hydration promotion caused by SAP mainly occurred in the deceleration period and attenuation period. SAP can significantly mitigate the autogenous shrinkage when the content ranged from 0 to 0.5%. Microstructure characteristics showed that pores and gaps were introduced when SAP was added. The microstructure difference caused by SAP contributed to the inferior mechanical behaviors of cement mortars treated by SAP.
P K Mehta, P J M Monteiro. Concrete: Microstructure, Properties and Materials. New York: McGraw-Hill Education, 2013
2
B Lothenbach, G Le Saout, E Gallucci, K Scrivener. Influence of limestone on the hydration of Portland cements. Cement and Concrete Research, 2008, 38(6): 848–860 https://doi.org/10.1016/j.cemconres.2008.01.002
3
M Kaszyńska. Early age properties of high-strength/high-performance concrete. Cement and Concrete Research, 2002, 24(2): 253–261 https://doi.org/10.1016/S0958-9465(01)00014-2
4
A Williams, A Markandeya, Y Stetsko, K Riding, A Zayed. Cracking potential and temperature sensitivity of metakaolin concrete. Construction & Building Materials, 2016, 120: 172–180 https://doi.org/10.1016/j.conbuildmat.2016.05.087
5
D Bentz, M Geiker, K Hansen. Shrinkage-reducing admixtures and early-age desiccation in cement pastes and mortars. Cement and Concrete Research, 2001, 31(7): 1075–1085 https://doi.org/10.1016/S0008-8846(01)00519-1
6
P Lura, O M Jensen, K van Breugel. Autogenous shrinkage in high-performance cement paste: An evaluation of basic mechanisms. Cement and Concrete Research, 2003, 33(2): 223–232 https://doi.org/10.1016/S0008-8846(02)00890-6
7
E I Tazawa, S Miyazawa. Influence of constituents and composition on autogenous shrinkage of cementitious materials. Magazine of Concrete Research, 1997, 49(178): 15–22 https://doi.org/10.1680/macr.1997.49.178.15
8
L Wu, N Farzadnia, C Shi, Z Zhang, H Wang. Autogenous shrinkage of high performance concrete: A review. Construction & Building Materials, 2017, 149: 62–75 https://doi.org/10.1016/j.conbuildmat.2017.05.064
9
D P Bentz, E J Garboczi, C J Haecker, O M Jensen. Effects of cement particle size distribution on performance properties of Portland cement-based materials. Cement and Concrete Research, 1999, 29(10): 1663–1671 https://doi.org/10.1016/S0008-8846(99)00163-5
10
A A Melo Neto, M A Cincotto, W Repette. Drying and autogenous shrinkage of pastes and mortars with activated slag cement. Cement and Concrete Research, 2008, 38(4): 565–574 https://doi.org/10.1016/j.cemconres.2007.11.002
11
W Song, J Yin. Hybrid effect evaluation of steel fiber and carbon fiber on the performance of the fiber reinforced concrete. Materials (Basel), 2016, 9(8): 704 https://doi.org/10.3390/ma9080704
12
J Liu, C Shi, X Ma, K H Khayat, J Zhang, D Wang. An overview on the effect of internal curing on shrinkage of high performance cement-based materials. Construction & Building Materials, 2017, 146: 702–712 https://doi.org/10.1016/j.conbuildmat.2017.04.154
13
M Zhang, C Tam, M Leow. Effect of water-to-cementitious materials ratio and silica fume on the autogenous shrinkage of concrete. Cement and Concrete Research, 2003, 33(10): 1687–1694 https://doi.org/10.1016/S0008-8846(03)00149-2
14
E Ghafari, S A Ghahari, H Costa, E Júlio, A Portugal, L Durães. Effect of supplementary cementitious materials on autogenous shrinkage of ultra-high performance concrete. Construction & Building Materials, 2016, 127: 43–48 https://doi.org/10.1016/j.conbuildmat.2016.09.123
15
D P Bentz. Mixture proportioning for internal curing. Concrete International, 2005, 27(2): 35–40
16
V Mechtcherine, C Schröfl, M Wyrzykowski, M Gorges, P Lura, D Cusson, J Margeson, N De Belie, D Snoeck, K Ichimiya, S I Igarashi, V Falikman, S Friedrich, J Bokern, P Kara, A Marciniak, H W Reinhardt, S Sippel, A Bettencourt Ribeiro, J Custódio, G Ye, H Dong, J Weiss. Effect of superabsorbent polymers (SAP) on the freeze-thaw resistance of concrete: Results of a RILEM interlaboratory study. Materials and Structures, 2017, 50(1): 14–19 https://doi.org/10.1617/s11527-016-0868-7
17
C Schröfl, V Mechtcherine, M Gorges. Relation between the molecular structure and the efficiency of superabsorbent polymers (SAP) as concrete admixture to mitigate autogenous shrinkage. Cement and Concrete Research, 2012, 42(6): 865–873 https://doi.org/10.1016/j.cemconres.2012.03.011
18
Y Yang, M D Lepech, E H Yang, V C Li. Autogenous healing of engineered cementitious composites under wet-dry cycles. Cement and Concrete Research, 2009, 39(5): 382–390 https://doi.org/10.1016/j.cemconres.2009.01.013
19
B Sun, H Wu, W Song, Z Li, J Yu. Design methodology and mechanical properties of Superabsorbent Polymer (SAP) cement-based materials. Construction & Building Materials, 2019, 204: 440–449 https://doi.org/10.1016/j.conbuildmat.2019.01.206
20
M Wyrzykowski, P Lura, F Pesavento, D Gawin. Modeling of water migration during internal curing with superabsorbent polymers. Journal of Materials in Civil Engineering, 2012, 24(8): 1006–1016 https://doi.org/10.1061/(ASCE)MT.1943-5533.0000448
21
N Vu-Bac, M Bessa, T Rabczuk, W K. Liu A multiscale model for the quasi-static thermo-plastic behavior of highly cross-linked glassy polymers. Macromolecules, 2015, 48(18): 6713–6723
22
D Snoeck, N de Belie. Repeated autogenous healing in strain-hardening cementitious composites by using superabsorbent polymers. Journal of Materials in Civil Engineering, 2016, 28(1): 04015086 https://doi.org/10.1061/(ASCE)MT.1943-5533.0001360
23
S I Igarashi, A Watanabe. Experimental study on prevention of autogenous deformation by internal curing using super-absorbent polymer particles. In: International RILEM Conference on Volume Changes of Hardening Concrete: Testing and Mitigation. Lyngby: RILEM, 2006
24
N Vu-Bac, R Rafiee, X Zhuang, T Lahmer, T. Rabczuk Uncertainty quantification for multiscale modeling of polymer nanocomposites with correlated parameters. Composites Part B: Engineering, 2015, 68: 446–464
25
N Vu-Bac, M Silani, T Lahmer, X Zhuang, T. Rabczuk A unified framework for stochastic predictions of mechanical properties of polymeric nanocomposites. Computational Materials Science, 2015, 96: 520–535
P Lura, F Durand, O M Jensen. Autogenous strain of cement pastes with superabsorbent polymers. In: International RILEM Conference on Volume Changes of Hardening Concrete: Testing and Mitigation. Lyngby: RILEM, 2006
28
N Vu-Bac, T Lahmer, Y X Zhang, X Zhuang, T Rabczuk. Stochastic predictions of interfacial characteristic of polymeric nanocomposites (PNCs). Composites Part B: Engineering, 2014, 59: 80–95
29
V Mechtcherine, M Gorges, C Schroefl, A Assmann, W Brameshuber, A B Ribeiro, D Cusson, J Custódio, E F da Silva, K Ichimiya, S Igarashi, A Klemm, K Kovler, A N de Mendonça Lopes, P Lura, V T Nguyen, H W Reinhardt, R D T Filho, J Weiss, M Wyrzykowski, G Ye, S Zhutovsky. Effect of internal curing by using superabsorbent polymers (SAP) on autogenous shrinkage and other properties of a high-performance fine-grained concrete: Results of a RILEM round-robin test. Materials and Structures, 2014, 47(3): 541–562 https://doi.org/10.1617/s11527-013-0078-5
30
J Justs, M Wyrzykowski, D Bajare, P Lura. Internal curing by superabsorbent polymers in ultra-high performance concrete. Cement and Concrete Research, 2015, 76: 82–90 https://doi.org/10.1016/j.cemconres.2015.05.005
31
G Sant, B Lothenbach, P Juilland, G Le Saout, J Weiss, K Scrivener. The origin of early age expansions induced in cementitious materials containing shrinkage reducing admixtures. Cement and Concrete Research, 2011, 41(3): 218–229 https://doi.org/10.1016/j.cemconres.2010.12.004
32
S Oh, Y C Choi. Superabsorbent polymers as internal curing agents in alkali activated slag mortars. Construction & Building Materials, 2018, 159(20): 1–8 https://doi.org/10.1016/j.conbuildmat.2017.10.121