Filling the Bricks

Even though it was never really under serious consideration for the production of an architectural structure, the first experiments of filling the bricks with something to make them more sturdy was made with gypsum. We quickly moved on, however, to filling them with a mixture of cement and different granulates such as vermiculite, perlite, and leca balls to make the bricks weigh less. Depending on the position of each brick in the structure different amounts of granulates were put into the cement. More granulates were added to the mixture when filling bricks higher up in the structure, making them lighter in comparison to bricks closer to the ground.

Out of the three different granulates used, the vermiculite and the perlite, being easy to mix with the cement and able to get into every nook and cranny of even the most intricate bricks, worked best. The downside, however, of these two, is the price. They are substantially more expensive than leca balls.

With the leca balls added to the cement, we experienced that the mixture did not achieve in filling the bricks up entirely, as the size of the leca balls (even though we crushed them thoroughly) restricted them somewhat in that matter. Also, the bricks got considerably heavier using leca balls compared to when using vermiculite or perlite, something that was further emphasized the more crushed the leca balls were.

To actually fill the bricks, we embedded them partially in sand. We noticed that having a flat surface, such as foam board or a piece of wood underneath each brick, helped to make the cement and granulates mixture flat at the bottom, flush with the lower end of each brick. However, this was something that we did not do when filling the bricks for the fourth prototype - the Weave. By not using foam board, or a sheet of wood in this case, we were able to leave a bit of room for the mortar to bond instead.