DTPA-coated synthetic calcined gypsum is provided with alpha-like properties and obtained by spray-coating the synthetic caclined gypsum with DTPA. Cementitious compositions comprising DTPA-coated synthetic calcined gypsum and low water demand are provided as well. Methods for controlling an open time of a cementitious slurry by increasing or decreasing the amount of DTPA-coated synthetic calcined gypsum in the slurry are provided as well.

DTPA-coated synthetic calcined gypsum is provided with alpha-like properties and obtained by spray-coating the synthetic caclined gypsum with DTPA. Cementitious compositions comprising DTPA-coated synthetic calcined gypsum and low water demand are provided as well. Methods for controlling an open time of a cementitious slurry by increasing or decreasing the amount of DTPA-coated synthetic calcined gypsum in the slurry are provided as well.

A method of delivering a microbe or enzyme to a selected location comprises conveying a coated aggregate to a selected location; wherein the coated aggregate comprises an aggregate and a coating disposed on the aggregate; the coating comprising a polymer matrix and a calcium carbonate producing agent comprising a microbe, an enzyme, or a combination comprising at least one of the foregoing.

A method of delivering a microbe or enzyme to a selected location comprises conveying a coated aggregate to a selected location; wherein the coated aggregate comprises an aggregate and a coating disposed on the aggregate; the coating comprising a polymer matrix and a calcium carbonate producing agent comprising a microbe, an enzyme, or a combination comprising at least one of the foregoing.

Methods and an associated system for processing unhardened concrete are disclosed. With these methods, the porosity of the unhardened concrete is significantly increased to decrease the strength so much that it can be easily broken up for sale or reuse. In at least one embodiment, the method includes adding a large volume of foam to the returned unhardened concrete and then mixing the foam with the returned concrete in the ready-mix concrete truck or other concrete mixing devices at any location including the jobsite, enroute to the concrete plant, or at the concrete plant. Through the mixing of foam with the returned concrete, the hydrated cement and aggregate particles are separated by large volumes of air voids, which significantly increase the porosity and dramatically reduce the strength of the returned concrete. The treated concrete is discharged and allowed to solidify in this weakened state, after which it is easily broken into loose particulate material that can be sold or reused.

Methods and an associated system for processing unhardened concrete are disclosed. With these methods, the porosity of the unhardened concrete is significantly increased to decrease the strength so much that it can be easily broken up for sale or reuse. In at least one embodiment, the method includes adding a large volume of foam to the returned unhardened concrete and then mixing the foam with the returned concrete in the ready-mix concrete truck or other concrete mixing devices at any location including the jobsite, enroute to the concrete plant, or at the concrete plant. Through the mixing of foam with the returned concrete, the hydrated cement and aggregate particles are separated by large volumes of air voids, which significantly increase the porosity and dramatically reduce the strength of the returned concrete. The treated concrete is discharged and allowed to solidify in this weakened state, after which it is easily broken into loose particulate material that can be sold or reused.

Methods and an associated system for processing unhardened concrete are disclosed. With these methods, the porosity of the unhardened concrete is significantly increased to decrease the strength so much that it can be easily broken up for sale or reuse. In at least one embodiment, the method includes adding a large volume of foam to the returned unhardened concrete and then mixing the foam with the returned concrete in the ready-mix concrete truck or other concrete mixing devices at any location including the jobsite, enroute to the concrete plant, or at the concrete plant. Through the mixing of foam with the returned concrete, the hydrated cement and aggregate particles are separated by large volumes of air voids, which significantly increase the porosity and dramatically reduce the strength of the returned concrete. The treated concrete is discharged and allowed to solidify in this weakened state, after which it is easily broken into loose particulate material that can be sold or reused.

Methods and an associated system for processing unhardened concrete are disclosed. With these methods, the porosity of the unhardened concrete is significantly increased to decrease the strength so much that it can be easily broken up for sale or reuse. In at least one embodiment, the method includes adding a large volume of foam to the returned unhardened concrete and then mixing the foam with the returned concrete in the ready-mix concrete truck or other concrete mixing devices at any location including the jobsite, enroute to the concrete plant, or at the concrete plant. Through the mixing of foam with the returned concrete, the hydrated cement and aggregate particles are separated by large volumes of air voids, which significantly increase the porosity and dramatically reduce the strength of the returned concrete. The treated concrete is discharged and allowed to solidify in this weakened state, after which it is easily broken into loose particulate material that can be sold or reused.

A method for synthesizing calcium-silicate-based porous particles (CSPPs) is described. Control over CSPP morphology and pore size is achieved through a refined solution-based synthesis, allowing loading of a variety of sealants. These particles, upon external stimuli, release the loaded sealant into the surrounding material. Methods of loading the CSPPs with loading sealant are described. The CSPPs may be used in pure form or mixed with another material to deliver self-healing, sealing and multi-functional properties to a physical structure. The composition of the CSPPs is described, along with methods of use of the CSPPs.

A method for synthesizing calcium-silicate-based porous particles (CSPPs) is described. Control over CSPP morphology and pore size is achieved through a refined solution-based synthesis, allowing loading of a variety of sealants. These particles, upon external stimuli, release the loaded sealant into the surrounding material. Methods of loading the CSPPs with loading sealant are described. The CSPPs may be used in pure form or mixed with another material to deliver self-healing, sealing and multi-functional properties to a physical structure. The composition of the CSPPs is described, along with methods of use of the CSPPs.