Lightweight Portland Cement Mixtures with Perlite for 3D printing of Concrete Structures

Abstract

3D printed concrete is a special type of concrete that can be laid through a 3D printer layer by layer without any formwork support or vibration. Important performance indicators of this concrete: rheology, mechanical properties, durability, can be optimized by choosing various materials. The purpose of this work is to use a mineral additive - perlite - in 3D concrete. In the studies, the pearlite content was up to 11.5%. Rheological tests of modified cement mortars were carried out using a rotary rheometer Rheotest RN 4.1, determining flow curves, ultimate shear stresses and plastic viscosity after mixing and after 60 min. Volumetric coefficient of water separation was calculated, the density and compressive strength were determined. It can be stated that the pearlite additive improves the formability of concrete mixtures using 3D printing technology, reduces the density of concrete, which increases the stability of the concrete mixture and reduces the thermal conductivity of concrete during the exploatation of the product.