Nozzle 2.0
HPA
Test object: HPA Test goal: Testing the new batch of accelerator diluted 1:1.
| Test 1 | 1:1 Masterroc (167) 2 l/h + Duomix + HP 2.0 + Possolit retarder .1% (premix w.) |
| Test 2 | 1:1 Masterroc (167) 3 l/h + Duomix + HP 2.0 + Possolit retarder .1% (premix w.) |
| ratio water 0,18 van 0,17 (water tot premix) | |
| Test 3 | 1:1 Masterroc (167) 4.5 l/h + Duomix + HP 2.0 + Possolit retarder .1% (premix w.) |
Remarks:
• DT 3 was disabled (had influence on the readings of DT 2 and DT 1) (unfortunate) • Lars: Typical example of whatever
Test results: 1. More accelerator results in more fluctuations of the pressure in dt-2 2. The print was unevenly hardened. (left side vs right side of layer nozzle) 3. accelerator buffer vessel, started leaking due to pressure buildup. 4. Water / accelerator switching might cause instability / squirting.
Potential next tests:
Option 1: (Lars) 1. Printing with more retarder/plasticizer 2. Dilute accelerator more
Option 2: (Kees) 3. Higher water content in initial mix 4. More plasticizer/retarder (to minimize the fluctuations in pressure) 5. Less diluted accelerator (as buckling is primary failure mode)
General comment: 1. Printing the cylinder vs HPA (more standardized testing) 2. Test less, know more.
| Time | Remarks | Measurement |
|---|---|---|
| 14:06 | Start Water dry-run Lmec | |
| 14:08 | Connecting duo-mix to nozzle | |
| 14:11 | dt-2 shows a readout error, there is a relationship between dt-1, dt-2 dt-3 | |
| 14:20 | Whatever, start the duomix | |
| 14:21 | Stop Stop (duomix), DT 1 > 20 bar | |
| 14:22 | DT 1 < 4 bar | |
| 14:23 | Duo-mix start DT-1 2 bar | |
| 14:24 | Duo-mix and water off (start accelerator) | |
| 14:27 | Start nozzle, concrete is running | 22.1˚C temp. amb. |
| 14:31 | Accelerator valve open Dt1- 3 bar | |
| 14:32 | Nozzle speed 40% to 50% | |
| 14:32 | Pressure dt-2 9 bar | |
| 14:34 | Lmec on water | |
| 14:34 | Duo-mix off |
Conclusion setup:
- Pressure sensors work incorrectly, decided to do the test anyway.
Test 1: 2l/h Masterroc 1:1 - water temp: (?) | Air temp: 21˚C
| Time | Remarks | Measurement |
|---|---|---|
| Start test 1 | ||
| 14:36 | Ratio duo-mix water mixture 0.17 to 0.18 | |
| 14:37 | Nozzle start | |
| 14:38 | Accelerator on | |
| 14:39 | Start print, nozzle speed to 55% | |
| 14:40 | Nozzle speed to 60% | |
| 14:40 | Temperature nozzle | Temp nozzle 38˚C |
| 14:41 | Dt-2 Stabilizes at 11 bar | |
| 14:42 | Nozzle speed to 50% | |
| 14:44 | Volkert suspects not enough accelerator on a “finger-test” on the initial layer | Accelerator to 3l/h |
| 14:45 Buckling failure layer 7. In the inside layer | ||
| 14:46 Cleaning for test 2 |
Conclusion test 1:
Strength development of the concrete is slow with 2l/h Masterroc 1:1, buckling failure after layer 7.
Annotation Volker during printing: Change accelerator:water ratio, suggestion (Accelerator : water from 1:1 to 1:75)
Test 2: 3l/h Masterroc 1:1 (60% motor) - water temp: (?) | Air temp: 22˚C
| Time | Remarks | Measurement |
|---|---|---|
| 14:46 | Start test 2 | |
| 14:46 | First layer 45% robot speed | |
| 14:47 | Dt_2 steady at 10 bar | |
| 14:48 | “Ripple formation” (print surface is ugly?) | |
| 14:49 | Lars is going steady and the print too | |
| 14:52 | Dt-2 steady 9.5 bar | L0 31 ˚C |
| L5 38 ˚C | ||
| 14:53 | Pressure drops a little. (dt-2) | |
| 14:54 | Bottom layer too soft, (assumption, the print object will fail) | |
| 14:55 | Layer prints next to previous layer, buckling occurs. Layer 12 | 22.1˚C |
| 14:56 | Lmec accelerator to water |
Conclusion test 2:
Stable results, increase in strength development with 3l/h Masterroc 1:1, printed layers from 7 to 12.
Annotation Kees: Interesting decrease in temperature, what could be the reason?
Test 3: 4l/h Masterroc 1:1 (Error: robot-speed 45% whole print) - water temp: (?) | Air temp: 22˚C
| Time | Remarks | |
|---|---|---|
| 14:58 | Start test 3 | |
| 14:59 | Nozzle 30,3 ˚C, pressure dt-2 11.5 | |
| 15:02 | Start print, D-t 2 aggressive | |
| 15:02 | visual squirting (probable due to air-bubbles) | |
| 15:03 | 55 seconds per layer (Robotspeed 45%) | |
| 15:04 | Leaking pressure valve Lmec dt-2 10.5 | |
| 15:06 | Temperature Mortar 36.5 ˚C, 32 ˚C nozzle | Mortar 36.5 ˚C |
| 15:06 | Squirting | L0: 33 ˚C |
| 15:07 | D-t 2 unstable 11.5 bar | |
| 15:08 | Noticeable difference in strength printed structure between test 3 and test 2 and 1. | |
| 15:08 | Visual squirting. | |
| 15:06 | Temperature Mortar 36.5 ˚C, 32 ˚C | |
| 15:08 | Squirting | |
| 15:09 | Pressure buildup Emec, leakage buffer vessel , stop test 3. |
Conclusion test 3:
Pressure in DT_2 is fluctuating more in test 3. (15:04) Leaking of the pressure valve resulted in a slight drop in DT_2. Additionally the printed layers showed an uneven distribution of accelerator.
Pressure increased to 11.5 bar with an increase to 4.5 l/h.