Buildability analysis on squared profile structure in 3D concrete printing (3DCP)

Figures & data

Table 1. Input time-dependent material properties for numerical modelling.

Material property	Symbol	Input data for numerical model	Units
Poisson’s ratio	ν	0.4	–
Young modulus	E(t)	0.0005 × t + 0.0329	N/mm^2
Density	ρ	2.066 × 10^−9	Tonnes/mm³
Cohesion	C(t)	0.00002538 × t + 0.0051628	–
Dilatancy angle	Ψ	∼13	–
Angle of internal friction	φ	0.1074 × t + 57.439	–

Table 2. 3DCP and numerical simulation results for buildability of structures.

Analysis type	No. of layers/steps	Buildability (mm)	Error
3DCP experiments	13	200.0	∼6.3%
	14
	13
Numerical simulations	25	187.5

Figure 1. Numerical model validation for buildability of 3DCP geopolymer structure. 3DCP experiment (left) numerical simulation results (right) after (a) 4 layers, (b) 8 layers, and (c) 13 layers.

Table 3. Sensitivity analysis on effect of designed height on buildability.

Analysis type	Designed height (mm)	No. of layers/steps	Buildability (mm)
3DCP experiments	–	13.33	200.0
Numerical simulations	H300	25.00	187.5
	H450	25.01	187.6
	H600	25.02	187.7

Figure 2. Effect of printing speed and layer width on buildability of 3DCP structures.

Table 4. Sensitivity analysis on effect of process parameters on buildability of structures.

Run	Printing speed (mm/s)	Layer width (mm)	No. of steps to failure	Buildability (mm)
1	20	15	9.69	145.4
2	20	30	13.88	208.2
3	20	45	27.37	410.6
4	50	15	8.94	134.1
5	50	30	11.84	177.6
6	50	45	26.00	390.0
7	80	15	8.92	133.8
8	80	30	11.45	171.8
9	80	45	25.33	380.0

Figure 3. Failure of 3DCP structures 3D-printed under different processing conditions.