Initial properties of 3D printing concrete using Rice Husk Ash (RHA) as Partial Cement Replacement

Abstract

3D printing concrete is an alternative technology for construction industry that are gaining interest among the developers and contractors worldwide. 3D printing concrete requires a good quality printing material that are buildable, strong and durable to be used as construction material. This present study uses Rice Husk Ash (RHA) as cement material replacement in in 3D printing concrete. Initial investigation was carried out to assess the suitability of RHA as cement replacement by conducting basic cement test such as cement consistency, setting time and workability of the mortar. The amount of RHA was constant at 20% used as cement replacement. From this study, the appropriate water-binder ratio of RHA cement replacement was 0.45:1. As for setting time, the time required for mortar mix to be transport and delivered through the nozzles for 3D printing was achieved by implemented the 20% RHA as cement replacement which are initial time at 155 minutes and final time at 312 minutes. The flowability of the mortar with RHA were found to be printable and achieve the requirements of mortar for 3D printing. Hence, RHA exhibits promising material to be used as cement replacement in 3D printing construction.

Potential of Reusing 3D Printed Concrete (3DPC) Fine Recycled Aggregates as a Strategy towards Decreasing Cement Content in 3DPC

“…The results showed a rapid increase in mechanical properties (initial build-up of E dyn ) starting after about 5 h and 30 min for mixes R0 and R10, which could be assumed as the final setting time. This time aligns with the time presented in [ 52 ] (5.33 h) and is slightly lower than the time presented in this study [ 53 ] (7 h and 10 min). For mixes R20–R50, the rapid increase in mechanical properties is delayed (up to 13 h and 30 min for the R50 mix).…”

Advancement in Sustainable 3D Concrete Printing: A Review on Materials, Challenges, and Current Progress in Australia

“…The chemical reaction in the concrete matrix would not be completed, resulting in weaker strength if the water content is low. However, excessive water should be avoided because it reduces the strength and buildability of 3DCP [63]. The longer final setting time of 3DCP contributes to the smooth flowability, extrudability, and reduced buildability and strength between layers resulting in structural collapse.…”

“…Several selected mixed proportions are shown in Table 3. Fine powder additive mixtures can densify the concrete structure by filling voids and pores, hence improving the flowability of concrete [63]. However, the partial replacement of cement by RHA reduces the flowability of the mix due to its porous nature, which absorbs physical water from its surroundings, resulting in the densification of the cement matrix [63].…”

“…Incorporation of RHA has shown a significant improvement in the rheology of mortar at the rate required for construction using 3D printing at a large scale. However, the successful mix designs that contain RHA had shown limitations in replacement proportions [63] and particle size of RHA, as shown in Table 1.…”

Building a Greener Future: Advancing Concrete Production Sustainability and the Thermal Properties of 3D-Printed Mortars

“…Table 3 summarises the waste utilisation regarding 3DCP with referenced articles and assesses the impact on specific fundamental properties, such as the pumpability, flowability, buildability, viscosity, interlayer bond, shrinkage, and more. Variations on setting time, with good extrudability and buildability [39] Fly ash (FA) and granulated blast-furnace slag (S) 0:60% PC The superior material efficiency index [47] Rice husk ash 20% PC ↑ Workability than control [97] Municipal sludge waste ashes (fly and bottom) and nylon fibres (NF) ↓ decreased; ↑ increased; -same.…”