Abstract
Two polycarboxylate ether (PCE) superplasticizers with different molar masses and functionalities were studied in relation to their strain and time-dependant rheological properties. The effect of dosage on cement paste fluidity and structural-build up was of particular interest. Through size exclusion chromatography (SEC) the relative molar mass and polydispersity index (PDI) was determined. Superplasticizer A (SP-A) was found to be three times the molar mass of superplasticizer B (SP-B). The dosage limitations were then determined through a spread flow test. The SP-B, with a lower molar mass, and a backbone functionality of a methacrylate - ester, began to flow at higher dosages and with relatively small changes in dosage, a large impact on the fluidity was notable. Dynamic oscillatory rheology was used to determine structural build-up, as a non-destructive method. The structural build-up of cement paste is a time-dependent phenomenon therefore a time sweep was done. A constant strain and angular frequency, within the linear viscoelastic regime (LVE), was used. The LVE was determined through a series of oscillatory strain sweeps for cement pastes with and without SP-A and B. Thereafter the rate of rigidification (Gridge) and percolation time (tperc) as a function of hydration time was investigated.
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References
Bellotto, M.: Cement paste prior to setting: a rheological approach. Cem. Concr. Res. 52, 161–168 (2013)
Conte, T., Chaouche, M.: Rheological behavior of cement pastes under large amplitude oscillatory shear. Cem. Concr. Res. 89, 332–344 (2016)
Lei, L., Plank, J.: Synthesis and properties of a vinyl ether-based polycarboxylate superplasticizer for concrete possessing clay tolerance. Ind. Eng. Chem. Res. 53(3), 1048–1055 (2014)
Mostafa, A.M., Yahia, A.: New approach to assess build-up of cement-based suspensions. Cem. Concr. Res. 85, 174–182 (2016)
Mostafa, A.M., Yahia, A.: Physico-chemical kinetics of structural build-up of neat cement-based suspensions. Cem. Concr. Res. 97, 11–27 (2017)
Peng, X., Yi, C., Qiu, X., Deng, Y.: Effect of molecular weight of polycarboxylate-type superplasticizer on the rheological properties of cement pastes. Polym. Polym. Compos. 20(8), 725–736 (2012)
Ran, Q., Liu, J., Yang, Y., Shu, X., Zhang, J., Mao, Y.: Effect of molecular weight of polycarboxylate superplasticizer on its dispersion, adsorption, and hydration of a cementitious system. J. Mater. Civ. Eng. 28(5), 04015184 (2015)
Shi, C.: Recent developments of pc supeplasticizers. In: Second International Symposium on Design, Performance and Use of Self-Consolidating Concrete SCC 2009-China, June 5–7 2009, Beijing, China pp. 16–25 (2009)
Winnefeld, F., Becker, S., Pakusch, J., Götz, T.: Effects of the molecular architecture of comb-shaped superplasticizers on their performance in cementitious systems. Cem. Concr. Compos. 29(4), 251–262 (2007)
Wood, L.: Concrete Admixture Market Analysis by Type (Water Reducing, Waterproofing, Accelerating, Air-Entraining, Retarding), by Application (Residential, Non-Residential & Infrastructure) and Segment Forecasts, 2014–2025 (2017)
Yuan, Q., Xin, L., Khayat, K.H., Feys, D., Shi, C.: Small amplitude oscillatory shear technique to evaluate structural build-up of cement paste. Mater. Struct. 50(2), 112 (2017)
Acknowlegements
The authors thank the Deutsche Forschungsgemeinschaft (DFG) SPP 2005 “Opus Fluidum Futurum“ for funding. Project number 386871659
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Radebe, N.W., Klein, C.O., Lei, L., Wilhelm, M. (2020). Effect of Different Molecular Weights and Chemical Composition of Superplasticizers on the Structural Build-up of Cement Paste Using Dynamic Oscillatory Rheology. In: Boshoff, W., Combrinck, R., Mechtcherine, V., Wyrzykowski, M. (eds) 3rd International Conference on the Application of Superabsorbent Polymers (SAP) and Other New Admixtures Towards Smart Concrete. SAP 2019. RILEM Bookseries, vol 24. Springer, Cham. https://doi.org/10.1007/978-3-030-33342-3_21
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DOI: https://doi.org/10.1007/978-3-030-33342-3_21
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