Rheological properties of cement systems modified with mineral and plasticizing additives.

Introduction. In practice, it is required to obtain mixtures both of equal workability, estimated by standard technical indicators (cone sediment, spreading, etc.) and of different rheological characteristics. Diluent additives effectively reduce the yield strength and viscosity, however, the effect of mineral additives in combination with organic surfactants on the rheological parameters of cement dispersions has been poorly studied. The paper is devoted to the study of this issue.

Research methods. Finely dispersed quartz (S_ud=340 m²/kg) and marble (S_ud=320 m²/kg) obtained by grinding in a laboratory mill were used; binder CEM I 42.5 H of Oskolcement CJSC (t_n.cw=230 min; НГ=26 %, C3S=61,59 %, C2S=14,2 %, C3A=6,83 %, C4AF=3,73 %); superplasticizer Polyplast SP-1, hyperplasticizer Sunbo 2021. Rheological parameters of cement dispersions were determined at low shear rate gradients έ up to 25 sec^-1, which makes it possible to ensure the similarity of flow in laboratory and real conditions.

Results. It has been established that pure and mixed cement dispersions without diluent additives are rheologically complex bodies with the highest shear stress and plastic viscosity. Mineral modifiers in combination with plasticizing additives effectively reduce plastic viscosity and shear stress, and their flow transitions to the Newtonian fluid regime with a viscosity independent of the shear rate gradient. Rheological parameters without additional mixed cement dispersions depended on the type of mineral filler. At the same time, with the introduction of diluent additives, dosages and the chemical base of additives have a predominant effect on rheological parameters.

Conclusion. Mixed cement-marble and cement-quartz dispersions with the introduction of diluting additives are characterized by higher fluidity than cement dispersions. The introduction of plasticizing additives at certain dosages makes it possible to completely remove non-linearity, and the use of mineral fillers enhances the effectiveness of surfactants.

1. Lesovik V.S., Elistratkin M.Yu., Salniko va A.S., Kazlitina O.V. On the issue of improving the efficiency of high-strength self-compacting concretes. Regional architecture and engineering. 2021; 1(46): 20-27. (in Russ.)

2. Rakhimbayev Sh.M., Tolypina N.M., Khakhaleva E.N. Interrelation between plastic viscosity of cement systems and their rethehnological characteristics. The Russian Automobile and Highway Industry Journal. 2018; 15(2): 276-282. (In Russ.) DOI: https://doi.org/10.26518/2071-7296-2018-2-276-282

3. Ortiz-Álvarez N., Lizarazo-Marriaga J., Brandão P.F.B., Santos-Panqueva Y., et al. Rheological properties of cement-based materials using a biopolymer viscosity modifying admixture (BVMA) under different dispersion conditions. Cem. Concr. Compos. 2021; 124: 104224.

4. Pertsev V.T., Ledenev A.A. Development of effective complex organomineral additives for regulation of rheological properties of concrete mixtures: monograph. Voronezh: Voronezhskij GASU; 2012. (in Russ.)

5. Chen J., Qiao M., Gao N., Wu J., et al. Acrylate based post-acting polymers as novel viscosity modifying admixtures for concrete. Constr. Build. Mater. 2021; 312: 125414.

6. Shakhova L.D. On the compatibility of cements with plasticizing additives. Cement i ego primenenie. 2024; 4: 48–55. (in Russ.)

7. Rakhimbaev Sh.M., Logvinenko A.A. Rheological properties of materials for the construction of transport infrastructure facilities. Izvestiya vuzov. Stroitel`stvo. 2014; 5: 26–33. (in Russ.)

8. Khayat K.H., Meng, W., Vallurupalli K., Teng, L. Rheological properties of ultra-high-performance concrete – An overview. Cem. Concr. Res. 2019; 124: 105828.

9. Baoguo M.A., Huixian Wang. Rheological properties of self-compacting concrete paste containing chemical admixtures. Journal of Wuhan University of Technology-Mater. Sci. Ed. 2013; 28(2): 291–297.

10. Ji X., Pan T., Zhao W., Lu J., et al. Interaction of superplasticizers with C3A: Understanding the superplasticizer compatibility with cement. J. of Mater. in Civil Engin. 2023; 35(9): 15185.

11. Shrihari S., Seshagiri Rao M.V., Srinivasa Reddy V., Manasa A. Compatibility assessment of commercial cements with superplasticizers. ICMED 2020. E 3S Web of Conferences. 2020; 184: 01079.

12. Qiao M., Chen J., Gao N., et al. Effects of adsorption group and molecular weight of viscosity modifying admixtures on the properties of cement paste. J. Mater. Civ. Eng. 2022; 34: 04022148.

13. Menon S.M. Sathyan D., Anand K.B. Studies on rheological properties of superplasticised PPC paste. International Journal of Civil Engineering and Technology (IJCIET). 2017. 8(10): 939–947.

14. Lesovik V.S., Fomina E.V. A new paradigm of designing building composites to protect the human environment. Vestnik MGSU. 2019; 14(10): 1241-1257. (in Russ.)

15. Lesovik V.S., Sheremet A.А., Chulkova I.L., Zhuravleva A.E. Geonics (geomimetics) and search for optimal solutions in building materials science. The Russian Automobile and Highway Industry Journal. 2021;18(1):120-134. (In Russ.) DOI: https://doi.org/10.26518/2071-7296-2021-18-1-120-134

16. Zhang Q., Chen J., Zhu J., Yang Y., et al. Advances in organic rheology-modifiers (chemical admixtures) and their effects on the rheological properties of cement-based materials. Materials. 2022; 15: 8730.

17. Slyusar A.A., Shapovalov N.A., Poluek tova V.A. Regulation of rheological properties of cement mixtures and concretes with additives based on oxyphenolfurfural oligomers. Stroitel`ny`e materialy`. 2008; 7: 42–43. (in Russ.)

18. Rakhimbaev Sh.M., Stolypina N.M., Khakhaleva E.N. [The effect of fine sand filler on the effectiveness of diluent additives]. Vestnik SibADI. 2016; 3(49): 74–79. (in Russ.)

19. Chen J., Gao N., Wu J., Shan G., et al. Effects of the charge density of anionic copolymers on the properties of fresh cement pastes. Constr. Build. Mater. 2020; 263: 120207.

20. Ferraz D.-F., Martho A.C.R., Burns E.G., Romano R.C.O., et al. Effect of prehydration of Portland cement on the superplasticizer consumption and the impact on the rheological properties and chemical reaction. Revista IBRACON de Estruturas e Materiais. 2023; 16(2): 1–14.

21. Du J., Meng W., Khayat K.H., Bao Y., et al. New development of ultra-high-performance concrete (UHPC). Compos. Part B Eng. 2021; 224: 109220.