Advertisement

Rheological Control of 3D Printable Cement Paste and Mortars

  • Scott Z. JonesEmail author
  • Dale P. Bentz
  • Nicos S. Martys
  • William L. George
  • Austin Thomas
Conference paper
Part of the RILEM Bookseries book series (RILEM, volume 19)

Abstract

Recent advances in concrete construction such as three-dimensional concrete printing (3DCP) have given rise to new requirements on the control of both the hydration and rheology of cementitious materials. To meet these new demands, and to move toward adoption of 3DCP on a commercial scale, in-operando control of hydration and rheology will be required. In this study, two cement paste mixtures containing limestone powder of two different median particle sizes are used to create 3D printed structures with a cement paste printer. Hydration control in the form of acceleration is achieved with the addition of the limestone powder to the cement and rheology control is achieved by using limestone with different median particle sizes. Rheology measurements conducted concurrently with printed structures indicate that yield stress and a measure of thixotropy of the cement paste provide an indicator as to whether a material will produce a multi-filament free-standing structure for a given 3DCP system. Simulations of particles flowing in a pipe are used to study the rheological behavior of paste and mortar. For the case of a mortar, the flow rate of suspended particles (sand) follows the same functional form with driving force as the matrix fluid (cement paste). Shear-induced particle migration increases the density of particles toward the center of the pipe, a result that implies that the aggregates may not be uniformly distributed.

Keywords

Concrete 3D printing Pipe flow simulations Rheology control 

References

  1. 1.
    Lim, S., et al.: Developments in construction-scale additive manufacturing processes. Autom. Constr. 21(1), 262–268 (2012)CrossRefGoogle Scholar
  2. 2.
    Wangler, T., et al.: Digital concrete: opportunities and challenges. RILEM Tech. Lett. 1, 67–75 (2016)CrossRefGoogle Scholar
  3. 3.
    Perrot, A., Rangeard, D., Pierre, A.: Structural build-up of cement-based materials used for 3D-printing extrusion techniques. Mater. Struct. 49, 1213–1220 (2016)CrossRefGoogle Scholar
  4. 4.
    Kawashima, S., et al.: Rate of thixotropic rebuilding of cement paste modified with highly purified attapulgite clays. Cem. Concr. Res. 53, 112–118 (2013)CrossRefGoogle Scholar
  5. 5.
    ASTM International, West Conshohocken, PA. ASTM C150/C150M-17, Standard Specification for Portland Cement (2017)Google Scholar
  6. 6.
  7. 7.
    Ferraris, C.F., et al.: Certification of SRM 2492: Bingham paste mixture for rheological measurements. NIST SP 260-174 (2012)Google Scholar
  8. 8.
    Martys, N.S., et al.: A smoothed particle hydrodynamics-based fluid model with a spatially dependent viscosity: application to flow of a suspension with a non-newtonian fluid matrix. Rheol. Acta 49(10), 1059–1069 (2010)CrossRefGoogle Scholar
  9. 9.
    Suiker, A.S.J.: Mechanical performance of wall structures in 3D printing processes: theory, design tools and experiments. Int. J. Mech. Sci. 137, 145–170 (2018)CrossRefGoogle Scholar
  10. 10.
    Byron Bird, R., Armstrong, R.C., Hasseger, O.: Dynamics of Polymeric Liquids, vol. 1, 1st edn. Wiley, Hoboken (1987)Google Scholar
  11. 11.
    Le, T.T., et al.: Hardened properties of high-performance printing concrete. Cem. Concr. Res. 42, 558–566 (2012)CrossRefGoogle Scholar
  12. 12.
    Sanjayan, J.G., et al.: Effect of surface moisture on inter-layer strength of 3D printed concrete. Constr. Build. Mater. 172, 468–475 (2018)CrossRefGoogle Scholar
  13. 13.
    Ridgway, K., Tarbuck, K.J.: Voidage fluctuations in randomly-packed beds of spheres adjacent to a containing wall. Chem. Eng. Sci. 23, 1147–1155 (1968)CrossRefGoogle Scholar

Copyright information

© RILEM 2019

Authors and Affiliations

  • Scott Z. Jones
    • 1
    Email author
  • Dale P. Bentz
    • 1
  • Nicos S. Martys
    • 1
  • William L. George
    • 1
  • Austin Thomas
    • 2
  1. 1.National Institute of Standards and TechnologyGaithersburgUSA
  2. 2.University of New HavenWest HavenUSA

Personalised recommendations