Carbon-Sequestering Concrete Composition with Enhanced CO2 Absorption and Method of Manufacturing Thereof

A method of constructing and preserving the carbon-sequestering elements of a sidewalk comprising:

• pouring a carbon-sequestering geopolymer-algae concrete mixture into forms erected on grade, wherein the concrete mixture comprises 1-5% dried saltwater marine algae powder into the geopolymer-algae concrete mixture;
• finishing the concrete to achieve a 4 inch thickness concrete slab in the shape of a sidewalk segment;
• allowing atmospheric carbon dioxide to permeate into and diffuse through the concrete slab over time:
• facilitating carbon mineralization reactions between the atmospheric carbon dioxide and algae-derived calcium ions, magnesium ions, and alginate polymers released during periodic wetting and drying cycles;
• and
• precipitating and integrating stable calcium carbonate and magnesium carbonate compounds into the concrete slab matrix, stably locking in the absorbed carbon dioxide over an extended duration.

A carbon-sequestering geopolymer concrete composition comprising:

• 30-50% ground granulated blast furnace slag as a geopolymeric binder precursor,
• 30-40% gravel as a coarse aggregate,
• approximately 35% sand as a fine aggregate,
• 2-5% dried marine algae powder,
• 5-10% magnesium oxide powder,
• 5-10% calcium oxide powder,
• approximately 5% sodium hydroxide and approximately 5% sodium silicate as an alkali activator,
• wherein the composition achieves reduced carbon dioxide emissions compared to conventional concretes using traditional Portland cement.