Abstract: To reach the goal that 3D printing equipment requires and cost saving, this study used the ordinary Portland cement, mineral powder, accelerating agent and the other compound admixtures to prepare the cement-based concrete materials. The mix design, the kind and amount of accelerating agent and the dosage of compound adjusting retarders were studied to research the workability, viscosity and plasticity of the cement-based concrete materials. Facts proved that its performance are all good. And the setting time of that is adjustable of gradient form, which the range of the initial is 10-40mins and the final is 15-80mins. And the material is used to print a few simple fancy goods, which looks good, for flowerpot with roundness and square, penta-five pentagon and so on. It reflects that the speed is so far and controlled, the appearance looks knitted and layered.
Abstract: The purpose of this study is to discuss the properties of low water/cement ratio and high compressive strength pervious concrete. Two sizes of air-cooling electric arc furnace slag (EAFS), for the same size of 0.24 - 0.48 cm and 0.48 - 0.96 cm, were prepared as the coarse aggregates. Two water-to-cement ratios and three filled percentages (70, 80, and 90%) of voids by cement pastes were selected as variables. The unit weight, connected porosity, water permeability coefficient, compressive strength, and flexural strength of pervious concrete were conducted. Test results show that the pervious concrete with higher filled percentage of voids by cement paste has higher unit weight, compressive strength, and flexural strength and smaller connected porosity and water permeability coefficient. The lower the water/cement ratio and EAFS size, the superior the properties. At the water/cement ratio of 0.25, pervious concrete with EAFS size of 0.24 – 0.48 cm and 90% filled percentage of voids by cement pastes had the highest compressive strength of 35 MPa and flexural strength of 7 MPa.