Microstructure and Mechanical Properties of Cost-Efficient 3D Printed Concrete Reinforced with Polypropylene Fibers

Abstract

Studying emerging and cutting-edge digital construction techniques, especially the utilization of 3D printing for concrete/mortar materials, holds significant importance due to the potential benefits that these technologies might offer over the traditional approach of casting concrete in place. In this study, a mixture composed of Portland cement, water, sand, limestone filler and polypropylene fibers was utilized for 3D printed concrete production towards the sustainable constructions approach. The benefits that sustain this statement include reduced construction time and material requirements, diminished error and cost, increase in construction safety, flexibility of architectural design, and improved quality with much less construction cost and waste. The microstructure, fresh and hardened mechanical properties of the polypropylene fiber reinforced 3D concrete were investigated. The results indicated that it is essential to attain a slump measurement of approximately 40 mm and a slump flow within the range of 140 to 160 mm, as stipulated by relevant standards (ASTM C1437 and C230/C230 M), in order to create a 3D concrete mixture suitable for extrusion. Also, the effects of printing parameters, fiber dosage, material composition, and other factors on the 3D printed concrete strength were discussed, and the corresponding adjustments were addressed.