Methods for making construction material using enzyme producing bacteria

A method for producing construction material comprising:

• preparing a first solution which includes urease which is formed by enzyme producing bacteria;
• applying a first layer of loose pieces of aggregate to a substrate wherein gaps are formed between at least some of the pieces within the first layer;
• adding the first solution to the first layer;
• adding an amount of urea and an amount of calcium ions to the first layer;
• the first solution and the urea and calcium ions being added to the first layer simultaneously or at different times or in a different order;
• applying a second layer of loose pieces of aggregate to the first layer wherein gaps are formed between at least some of the pieces in the second layer and between at least some of the pieces at the boundary between the first layer and the second layer;
• adding a second amount of the first solution to the second layer;
• adding a second amount of urea and a second amount of calcium ions to the second layer;
• the second amount of the first solution and the second amount of urea and the second amount of calcium ions being applied simultaneously or at different times or in a different order;
• the calcium ions contributing to the formation of calcium carbonate;
• the calcium carbonate filling at least some of the gaps between the pieces of aggregate, bonding to the aggregate, whereby the first and second layers are bonded together and a solid construction material is formed.

A method for producing construction material using a computer numerical controlled deposition machine having at least first, second and third containers comprising:

• preparing a first solution which includes urease by enzyme producing bacteria;
• preparing a second solution which includes calcium ions;
• at least partially filling the first container with the first solution;
• at least partially filling the second container with the second solution;
• at least partially filling the third container with an amount of loose pieces of aggregate;
• applying a first layer of loose pieces of aggregate from the third container to a substrate;
• applying a first amount of the first solution from the first container to the first layer;
• applying a first amount of the second solution from the second container to the first layer;
• applying a first amount of urea to the first layer;
• the first amount of the first solution, the first amount of the second solution, and the first amount of urea being applied to the first layer simultaneously or at different times or in a different order;
• applying a second layer of loose pieces of aggregate from the third container to the first layer;
• applying a second amount of the first solution from the first container to the second layer;
• applying a second amount of the second solution from the second container to the second layer;
• applying a second amount of urea to the second layer;
• the second amount of the first solution, the second amount of the second solution, and the second amount of urea being applied to the second layer simultaneously or at different times or in a different order;
• the calcium ions forming calcium carbonate;
• the calcium carbonate filling at least some of the gaps between the pieces of aggregate, bonding to the aggregate, whereby the first and second layers are bonded together and a solid construction material is formed.