A low-density, high-strength concrete composition that is both self-compacting and lightweight, 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 an oven-dried density as low as 40 lbs./cu.ft. The concrete, at the density ordinarily found in structural lightweight concrete, has a higher strength and, at the strength ordinarily found in structural lightweight concrete, a lower density. 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.

Described are dry cast lightweight veneer blocks and a system and method of installing lightweight veneer blocks. The courses can be assembled without mortar between the courses. As an example, sides of the veneer blocks have areas that recede from an imaginary plane between adjacent veneer blocks to give a deep texturing and a shadow effect between veneer blocks. The installation system and method include a substrate, an air barrier applied to the substrate, a plurality of veneer blocks, and an adhesive applied between the plurality of veneer blocks and the air barrier.

An aggregate includes a polymeric foam present in a range of about 80 vol % to about 85 vol % of the aggregate. A cementitious matrix is present in a range of about 10 vol % to about 13 vol % of the aggregate. One or more resins are present in an amount of less than about 2 vol % of the aggregate, and one or more reinforcing fibers are present in an amount of less than about 1 vol % of the aggregate.

An aggregate includes a polymeric foam present in a range of about 80 vol % to about 85 vol % of the aggregate. A cementitious matrix is present in a range of about 10 vol % to about 13 vol % of the aggregate. One or more resins are present in an amount of less than about 2 vol % of the aggregate, and one or more reinforcing fibers are present in an amount of less than about 1 vol % of the aggregate.

A system and associated methods for processing unhardened concrete are disclosed. It at least one embodiment, the system for processing unhardened concrete includes a means to estimate a quantity of returned concrete; a foam adder to add foam to the quantity of returned concrete; a mixer to mix the added foam and returned concrete together to create treated concrete; a discharger to discharge the treated concrete; a discharge area configured in which to allow the treated concrete to set and harden; a converter to convert the hardened treated concrete into a particulate or aggregate form; and a user to determine the specific utilization of the particulate or aggregate form loose material.

A system and associated methods for processing unhardened concrete are disclosed. It at least one embodiment, the system for processing unhardened concrete includes a means to estimate a quantity of returned concrete; a foam adder to add foam to the quantity of returned concrete; a mixer to mix the added foam and returned concrete together to create treated concrete; a discharger to discharge the treated concrete; a discharge area configured in which to allow the treated concrete to set and harden; a converter to convert the hardened treated concrete into a particulate or aggregate form; and a user to determine the specific utilization of the particulate or aggregate form loose material.

A lightweight composite having an activated surface contains a lightweight hollow core particle having cement grains which may be adhered to the hollow core or embedded in the surface of the hollow core. The hollow core particle may be prepared from calcium carbonate and a mixture of clay, such as bentonite, and a glassy inorganic material, such as glass spheres, glass beads, glass bubbles, borosilicate glass and fiberglass.

A lightweight composite having an activated surface contains a lightweight hollow core particle having cement grains which may be adhered to the hollow core or embedded in the surface of the hollow core. The hollow core particle may be prepared from calcium carbonate and a mixture of clay, such as bentonite, and a glassy inorganic material, such as glass spheres, glass beads, glass bubbles, borosilicate glass and fiberglass.

Manufacturing lightweight aggregate (LWA) by a sintering technique requires a delicate balance among three conditions: forming sufficient amount of molten liquid phase during sintering; reaching an appropriate viscosity for solid-liquid suspension; and emitting sufficient amount of gas that can be entrapped by the liquid phase to form pores. LWAs were made from low-calcium and high-calcium Waste Coal Combustion Ash (W-CCA) including fly ash and bottom ash. A mass fraction of at least 40% liquid phase for fly ash and 50% for bottom ash is required for a successful entrapment of emitted gaseous phases during sintering. Larger pores were observed in the microstructure of LWA samples made using high-calcium W-CCA in comparison to low-calcium W-CCA. This result was mainly attributed to the high-calcium samples forming liquid phases with lower viscosity values and emitting higher amounts of gaseous phase during sintering than did the low-calcium samples. The gaseous phase was generated by hematite reduction and anhydrite decomposition.

Manufacturing lightweight aggregate (LWA) by a sintering technique requires a delicate balance among three conditions: forming sufficient amount of molten liquid phase during sintering; reaching an appropriate viscosity for solid-liquid suspension; and emitting sufficient amount of gas that can be entrapped by the liquid phase to form pores. LWAs were made from low-calcium and high-calcium Waste Coal Combustion Ash (W-CCA) including fly ash and bottom ash. A mass fraction of at least 40% liquid phase for fly ash and 50% for bottom ash is required for a successful entrapment of emitted gaseous phases during sintering. Larger pores were observed in the microstructure of LWA samples made using high-calcium W-CCA in comparison to low-calcium W-CCA. This result was mainly attributed to the high-calcium samples forming liquid phases with lower viscosity values and emitting higher amounts of gaseous phase during sintering than did the low-calcium samples. The gaseous phase was generated by hematite reduction and anhydrite decomposition.