3D printable mortar

Abstract

3D printing is proving its potential in the construction industry. The project implemented new principals and knowledge about 3DP. In fact, the project presented a systematic deep study of the relationships between the 3D printed shape and cementitious materials properties. Three main qualities were needed so that the Inkrete is considered printable: extrudability, workability and buildability. Where these three qualifications insure that Inkrete get out of the printing device and the printed shape does not collapse while the number of printed layers increase. Many trials were done to come up with an Inkrete suitable for 3D printing technique. Initially, an efficient link between the mixing procedure, the mix proportions and the mix specifications were established. And two mixes were adopted at the end of this project to study the behavior of the inkrete while printing: the first mix was done without using accelerator (M1) and the second mix was done using accelerator (M2). After getting the perfect printable mix, two main factors affected the printing procedure: first the geometrical shape of the structure and second the required break time between each set of successive layers. An optimum printed structure would be designed with internal supportive walls and using M2. Such a design will insure a faster printing procedure: more layers could be printed at a time compared to a design without internal walls with lower setting time required. Testing procedure was mainly done in two levels. First, slumb tests were performed to compare the consistency of fresh mortar before it sets between traditional mortar mix and Inkerte mix. Slump test were done on two Inkrete mixes, one using the new admixture only and the other using superplastisizer only. And the second level was the isothermal calorimetric test. M1 and M2 were tested to study the effect of accelerator on the inkrete mix. A third test was wished to be done which is the Rheology test. Its main purpose is to understand the effect of mixing on the flow of Inkrete, but no equipment was provided to do it.