Effect of Limestone Filler Dosage and Granulometry on the 3D printable Mixture Rheology

Abstract

The article presents the experimental results concerning the influence of the concentration and a particle size distribution of limestone filler on the rheological behaviour of cement pastes as matrixes of 3D printable concrete. The squeezing test is used in this paper as a rheological behaviour identification tool of cement-based materials in order to evaluate the extrudability and buildability. It has been established that introduction of filler as a factor changing the properties of solid phase in the system "cement + water" is an effective method for plasticity regulation and increasing the 3D printable cement-based materials resistance to load during the printing. Structural stability of cement paste can be improved by 2 times by introduction of filler with efficient ranging of a particle size in dosage of 20 – 40 % by weight of cement. Cement paste with limestone filler having a particle size distribution ranging from' to 75 μm is characterized by the optimal plasticity, structural strength and deformability under the load. Using limestone filler with equal particle size impairs these characteristics of cement paste.