Provided here are hemp-based concrete compositions and methods of production of these compositions. These compositions contain an aggregate containing coarse hemp hurd and an alkali-activated binder including a hemp powder derived from a woody core of a hemp plant.

Provided here are hemp-based concrete compositions and methods of production of these compositions. These compositions contain an aggregate containing coarse hemp hurd and an alkali-activated binder including a hemp powder derived from a woody core of a hemp plant.

Cement-SCM blends employ particle packing principles to increase particle packing density and reduce interstitial spacing between the cement and SCM particles. Particle packing reduces the amount of water required to obtain a cement paste having a desired flow, lowers the water-cementitious material ratio (w/cm), and increases early and long-term strengths. This may be accomplished by providing a hydraulic cement fraction having a narrow PSD and at least one SCM fraction having a mean particle size that differs from the mean particle size of the narrow PSD cement by a multiple of 3.0 or more to yield a cement-SCM blend having a particle packing density of at least 57.0%.

Cement-SCM blends employ particle packing principles to increase particle packing density and reduce interstitial spacing between the cement and SCM particles. Particle packing reduces the amount of water required to obtain a cement paste having a desired flow, lowers the water-cementitious material ratio (w/cm), and increases early and long-term strengths. This may be accomplished by providing a hydraulic cement fraction having a narrow PSD and at least one SCM fraction having a mean particle size that differs from the mean particle size of the narrow PSD cement by a multiple of 3.0 or more to yield a cement-SCM blend having a particle packing density of at least 57.0%.

A method may include comprising: defining engineering parameters of a proposed cement slurry, the engineering parameters comprising at least a compressive strength requirement, a density requirement, a storage time requirement, and a thickening time requirement; selecting, based at least in part on a model of compressive strength, a model of storage time, and the density requirement, at least a cement and mass fraction thereof, at least one supplementary cementitious material and mass fraction thereof, and a water and mass fraction thereof, such that a set cement formed from the cement, the at least one supplementary cementitious material, and the water meets or exceeds the compressive strength requirement and the density requirement; selecting, based at least in part on a model of thickening time, an accelerator and mass fraction thereof; and preparing a cement slurry comprising the cement and mass fraction thereof, the at least one supplementary cementitious material and mass fraction thereof, the water and mass fraction thereof, and the cement retarder and mass fraction thereof.

A method may include comprising: defining engineering parameters of a proposed cement slurry, the engineering parameters comprising at least a compressive strength requirement, a density requirement, a storage time requirement, and a thickening time requirement; selecting, based at least in part on a model of compressive strength, a model of storage time, and the density requirement, at least a cement and mass fraction thereof, at least one supplementary cementitious material and mass fraction thereof, and a water and mass fraction thereof, such that a set cement formed from the cement, the at least one supplementary cementitious material, and the water meets or exceeds the compressive strength requirement and the density requirement; selecting, based at least in part on a model of thickening time, an accelerator and mass fraction thereof; and preparing a cement slurry comprising the cement and mass fraction thereof, the at least one supplementary cementitious material and mass fraction thereof, the water and mass fraction thereof, and the cement retarder and mass fraction thereof.

A mortar composition, which includes (i) a treated palm oil fuel ash, wherein the treated palm oil fuel ash is the only binder present, (ii) a fine aggregate, (iii) an alkali activator containing an aqueous solution of sodium hydroxide and sodium silicate, and (iv) aluminum hydroxide as a strength enhancer. A cured mortar made from the mortar composition is also disclosed with advantageous compressive strength properties.

A low-density, high-strength concrete composition that is lightweight and self-compacting or non-self-compacting, with a low weight-fraction of aggregate to total dry raw materials, and a highly-homogenous distribution of a non-absorptive and closed-cell lightweight aggregate such as glass microspheres or copolymer polymer beads or a combination thereof, and the steps of providing the composition or components. Lightweight concretes formed therefrom have low density, high strength-to-weight ratios, and high R-value. The concrete has strength similar to that ordinarily found in structural lightweight concrete but at a lower density, such as an oven-dried density as low as 40 lbs./cu.ft. Such strength-to-density ratios range approximately from above 30 cu.ft/sq.in. to above 110 cu.ft/sq.in., with a 28-day compressive strength ranging from about 3400 to 8000 psi.

A low-density, high-strength concrete composition that is lightweight and self-compacting or non-self-compacting, with a low weight-fraction of aggregate to total dry raw materials, and a highly-homogenous distribution of a non-absorptive and closed-cell lightweight aggregate such as glass microspheres or copolymer polymer beads or a combination thereof, and the steps of providing the composition or components. Lightweight concretes formed therefrom have low density, high strength-to-weight ratios, and high R-value. The concrete has strength similar to that ordinarily found in structural lightweight concrete but at a lower density, such as an oven-dried density as low as 40 lbs./cu.ft. Such strength-to-density ratios range approximately from above 30 cu.ft/sq.in. to above 110 cu.ft/sq.in., with a 28-day compressive strength ranging from about 3400 to 8000 psi.

A process of sequestering CO.sub.2 is generally described. The process involves the use of geopolymeric precursors to which the CO.sub.2 is added. The process for a solid, cementitious material comprising geopolymer(s) and CO.sub.2.