Vegetal Concrete Masonry Unit and Method and System for Manufacture Thereof

A method for the preparation of a vegetal concrete masonry unit, the method comprising:

• treating crop residue in a retention tank with an alkali and water and passing the treated crop through a screw press to yield a treated crop residue;
• mixing Ground Granulated Blast Furnace Slag (GGBFS), individually or in combination with hydrated lime, with an activator powder for at least 5 minutes in a ribbon blender to constitute a binder;
• intermixing the treated crop residue, the binder and aggregates together in a pan mixer with water to form an alkali activated homogeneous paste/gel;
• and
• molding the homogenous paste/gel obtained in the intermixing step using a high-pressure hydraulic press capable of delivering a pressure of at least 2 MPa to form the vegetal concrete masonry unit;
• wherein the crop residue is treated with 0.1 M to 10M aqueous NaOH or equivalent alkali solution for a duration of 15 to 1500 minutes to improve compatibility between the crop residue and the binder;
• wherein the hydrated lime in the binder is at least 85 percent calcium hydroxide and is mixed with GGBFS in a 1:10 to 2:3 ratio;
• and
• wherein the sodium silicate activator powder is in an amount equal to 2.5-20% of the total mass of the GGBFS or the hydrated lime and the GGBFS in the ribbon blender to constitute the binder.