Saltcrete is a mixture of cement

Cement

In the most general sense of the word, a cement is a binder, a substance that sets and hardens independently, and can bind other materials together. The word "cement" traces to the Romans, who used the term opus caementicium to describe masonry resembling modern concrete that was made from crushed...

 with salt

Salt

In chemistry, salts are ionic compounds that result from the neutralization reaction of an acid and a base. They are composed of cations and anions so that the product is electrically neutral...

s and brine

Brine

Brine is water, saturated or nearly saturated with salt .Brine is used to preserve vegetables, fruit, fish, and meat, in a process known as brining . Brine is also commonly used to age Halloumi and Feta cheeses, or for pickling foodstuffs, as a means of preserving them...

, usually originating from liquid waste treatment plants. Its role is to immobilize hazardous waste

Hazardous waste

A hazardous waste is waste that poses substantial or potential threats to public health or the environment. According to the U.S. environmental laws hazardous wastes fall into two major categories: characteristic wastes and listed wastes.Characteristic hazardous wastes are materials that are known...

 and in some cases lower-level

Low level waste

Low-Level Waste is a term used to describe nuclear waste that does not fit into the categorical definitions for high-level waste , spent nuclear fuel , transuranic waste , or certain byproduct materials known as 11e wastes, such as uranium mill tailings...

 radioactive waste

Radioactive waste

Radioactive wastes are wastes that contain radioactive material. Radioactive wastes are usually by-products of nuclear power generation and other applications of nuclear fission or nuclear technology, such as research and medicine...

 in the form of solid material. It is a form of mixed waste

Mixed waste

Mixed waste can refer to any combination of waste types with different properties.Typically commercial and municipal wastes are mixtures of plastics, metals, glass, biodegradable waste including paper and textiles along with other nondescript junk....

.

Saltcrete is being replaced by saltstone, which is less permeable and leachable. Saltstone is a mixture of the salt cake (mostly sodium nitrate

Sodium nitrate

Sodium nitrate is the chemical compound with the formula NaNO3. This salt, also known as Chile saltpeter or Peru saltpeter to distinguish it from ordinary saltpeter, potassium nitrate, is a white solid which is very soluble in water...

 and other salts) with concrete

Concrete

Concrete is a composite construction material, composed of cement and other cementitious materials such as fly ash and slag cement, aggregate , water and chemical admixtures.The word concrete comes from the Latin word...

 and fly ash

Fly ash

Fly ash is one of the residues generated in combustion, and comprises the fine particles that rise with the flue gases. Ash which does not rise is termed bottom ash. In an industrial context, fly ash usually refers to ash produced during combustion of coal...

.