Rheological properties of self-compacting lightweight concrete mixtures on hollow microspheres

Introduction. Self-compacting concrete (SCC) technologies are actively used in modern construction, which are developing in the direction of lightweight self-compacting concrete (LWSCC) technology. The main advantage of LWSCC is to reduce the weight of concrete and reinforced concrete structures while maintaining structural integrity, load-bearing capacity and high mobility. The purpose of the study is to evaluate the rheology of the flow of the studied mixtures depending on the varying factors of W/C and the concentration of plasticizer Cpl and the ratio of filler (fractionated sand and quartz flour).

Materials and methods. The object of the study is concrete mixtures on hollow microspheres. The design average concrete density is 1,400 kg/m3. The following composition is presented: Portland cement, ceramic microspheres, complex silica additive, fractional sand, quartz flour, hyperplasticizer and water. The results of studies of the rheological characteristics of LWSCC were obtained. The key rheological parameters are shear stress and viscosity.

Results. Reducing the W/C increases the viscosity and shear stress of the concrete mix, regardless of the Cpl. A similar dependence is observed in compositions with variable Cpl. An increase in Cpl reduces the density of the mixture, reducing viscosity and shear stress. The limiting value of Cpl is noted, when this value is overcome by rheological parameters of mixtures tend to zero as the volume of the additive increases. The evaluation of the rheology of mixtures using the Ostwald de Waele equation shows the greatest importance of the W/C ratio for density and the possibility of changing the flow pattern of mixtures from pseudoplastic to dilatant with varying studied factors. Replacing the fraction of fractionated sand with flour from 100 to 0 % increases the density of the mixture by almost three times.

Conclusions. The results determining the possibility of changing the rheological nature of the LWSCC flow on hollow microspheres with varying studied factors are presented. A comparative analysis of the obtained rheological curves is performed using the Ostwald de Waele equation for heavy and light mixtures with hollow microspheres. The role of filler dispersion in controlling the rheological properties of the studied LWSCC is considered.

1. Adhikary S.K., Ashish D.K., Sharma H., Patel J., Rudzionis Z., Al-Ajamee M. et al. Lightweight self-compacting concrete : a review. Resources, Conservation & Recycling Advances. 2022; 15:200107. DOI: 10.1016/j.rcradv.2022.200107

2. Mandal R., Panda S.K., Nayak S. Rheology of concrete: critical review, recent advancements, and future prospectives. Construction and Building Materials. 2023; 392:132007. DOI: 10.1016/j.conbuildmat.2023.132007

3. Inozemtsev A.S., Korolev E.V. High-strength lightweight concretes : monograph. St. Petersburg, SPbGASU, 2022; 192. EDN UCJRAZ. (rus.).

4. Fedyuk R.S., Mochalov A.V., Lesovik V.S., Gridchin A.M., Fisher H.B. Composite bonding and self-fitting fibrobetons for protective facilities. Bulletin of the Belgorod State Technological University named after V.G. Shukhov. 2018; 7:77-85. DOI: 10.12737/article_5b4f02bf93df52.30110991. EDN XVLQJV. (rus.).

5. Mozgalev K.M., Golovnev S.G. Self-sealing concretes: application possibilities and properties. Akademicheskij vestnik UralNIIProekt RAASN. 2011; 4:55-60. EDN ONJNAZ. (rus.).

6. Sumin A.S. Lightweight self-sealing concrete and their prospects. New word in science: development strategies : collection of materials of the V International Scientific and Practical Conference. 2018; 10-14. EDN OUYFSS. (rus.).

7. Sumin A.S. Lightweight self–sealing concrete — the future of monolithic housing construction. Science, education, society: trends and prospects of development : collection of materials of the VI International Scientific and Practical Conference. 2017; 354-358. EDN YZEBVJ. (rus.).

8. Bychkov M.V., Udodov S.A. Light self compacting concrete as an effective constructional material. Online journal of Science Studies. 2013; 4(17):41. EDN RSHDSB. (rus.).

9. Adhikary S.K., Ashish D.K., Rudžionis Ž. Expanded glass as light-weight aggregate in concrete — a review. Journal of Cleaner Production. 2021; 313:127848. DOI: 10.1016/j.jclepro.2021.127848

10. Lee S.H., Kim H.J., Sakai E., Daimon M. Effect of particle size distribution of fly ash–cement system on the fluidity of cement pastes. Cement and Concrete Research. 2003; 33(5):763-768. DOI: 10.1016/S0008-8846(02)01054-2

11. Chen J.J., Kwan A.K. H. Superfine cement for improving packing density, rheology and strength of cement paste. Cement and Concrete Composites. 2012; 34(1):1-10. DOI: 10.1016/j.cemconcomp.2011.09.006

12. Zhang X., Han J. The effect of ultra-fine admixture on the rheological property of cement paste. Cement and Concrete Research. 2000; 30(5):827-830. DOI: 10.1016 /S0008-8846(00)00236-2

13. Karim Md.R., Zain Muhammad F.M., Jamil M., Lai Fook C., Islam Md.N. Use of Wastes in Construction Industries as an Energy Saving Approach. Energy Procedia. 2011; 12:915-919. DOI: 10.1016/j.egypro.2011.10.120

14. Rafeet A., Vinai R., Soutsos M., Sha W. Effects of slag substitution on physical and mechanical properties of fly ash-based alkali activated binders (AABs). Cement and Concrete Research. 2019; 122:118-135. DOI: 10.1016/j.cemconres.2019.05.003

15. Zeyad A.M., Almalki A. Influence of mixing time and superplasticizer dosage on self-consolidating concrete properties. Journal of Materials Research and Technology. 2020; 9(3):6101-6115. DOI: 10.1016/j.jmrt.2020.04.013

16. Inozemtsev A.S., Korolev E.V., Doung T.Q. Structural flow model of plasticized cement-mineral mixtures. Construction Materials. 2020; 4-5:90-96. DOI: 10.31659/0585-430X-2020-780-4-5-90-96. EDN CVBCCH. (rus.).

17. Inozemtsev A.S., Korolev E.V. Conditions for the manifestation of anomaly in the flow of plasticized cement-mineral mixtures. Industrial and Civil Engineering. 2021; 12:23-30. DOI: 10.33622/0869-7019.2021.12.23-30. EDN GMURMO. (rus.).

18. Nemocón S.A.G., Marriaga J.M.L., Suárez J.D.P. Rheological and hardened properties of self-compacting concrete using hollow glass microspheres as a partial replacement of cement. Construction and Building Materials. 2022; 342:128012. DOI: 10.1016/j.conbuildmat.2022.128012

19. Patent RU No. 2548303. High-strength light-weight fiber-reinforced concrete / Korolev E.V., Inozemtsev A.S.; application No. 2014114357/03 04/11/2014. Publ. 04/20/2015. EDN ZFGSHZ.

20. Inozemtsev A.S., Epikhin S.D. Conditions for the preparation of self-compacting lightweight concrete with hollow microspheres. Materials. 2023; 16(23):7288. DOI: 10.3390/ma16237288