Artificial stone made of a mixture of cement, aggregate (hard material), and water. In addition to its potential for immense compressive strength and its ability, when poured, to adapt to virtually any form, concrete is fire-resistant and has become one of the most common building materials in the world. The binder usually used today is portland cement. The aggregate is usually sand and gravel. Additives called admixtures may be used to accelerate the curing (hardening) process in low temperature conditions. Other admixtures trap air in the concrete or slow shrinkage and increase strength.
The entity contractually responsible for delivering project design and construction. The Design-Builder can assume several organizational structures, the four most common being a firm that possesses both design and construction resources in-house; a joint venture between designer and contractor; a contractor-led team with the designer in a subcontractor role; and a design-led team with the contractor in a subcontractor role.
Steel frame usually refers to a building technique with a “skeleton frame” of vertical steel columns and horizontal I-beams, constructed in a rectangular grid to support the floors, roof and walls of a building which are attached to the frame. The development of this technique made the construction of the skyscraper possible.
Remediation – Cleanup or other methods used to remove or contain a toxic spill or hazardous materials from a site. Stabilization – Conversion of the active organic matter in sludge into inert, harmless material.
Helical piles are ideal in areas of limited access, such as areas with low overhead or width restrictions. Installation is unaffected by weather or high water table. No vibration during installation means no damage to sensitive structures or instrumentation in the construction zone. The term Helical Piers, Screw Piles and Helical Piles are all used interchangeably.
Biosurfactants are surface-active substances synthesized by living cells. They have the properties of reducing surface tension, stabilizing emulsions, promoting foaming and are generally non-toxic and biodegradable. Biosurfactants enhance the emulsification of hydrocarbons, have the potential to solubilize hydrocarbon contaminants and increase their availability for microbial degradation. The use of chemicals for the treatment of a hydrocarbon polluted site may contaminate the environment with their by-products, whereas biosurfactant treatment may efficiently destroy pollutants, while being biodegradable themselves.
Completely tearing down buildings, razing them to the ground and removing the debris to a landfill or waste treatment facility.
Procedures to control fiber release from asbestos-containing materials in a building or to remove them entirely, including removal, encapsulation, repair, enclosure, encasement, and operations and maintenance programs.
The term heavy metal refers to a group of toxic metals including arsenic, chromium, copper, lead, mercury, silver, and zinc. Heavy metals often are present at industrial sites at which operations have included battery recycling and metal plating.
The Resource Conservation and Recovery Act, or RCRA, is a law that addresses the safe and environmentally responsible management of hazardous waste in the United States. The Environmental Protection Agency (EPA), which oversees RCRA compliance, defines waste as hazardous if it meets certain criteria. To qualify as hazardous or RCRA waste, a substance must first be a solid waste. It must then fit the EPA’s definition of a “listed” or “characteristic” waste. Stabilization – Conversion of the active organic matter in sludge into inert, harmless material.
In-Situ – In its original place; unmoved unexcavated; remaining at the site or in the subsurface.
Chlorinated Solvent – An organic solvent containing chlorine atoms (e.g., methylene chloride and 1,1,1-trichloromethane). Uses of chlorinated solvents are aerosol spray containers, in highway paint, and dry cleaning fluids.
Technology that oxidizes contaminants dissolved in ground water, converting them into insoluble compounds.
Soil washing is an innovative treatment technology that uses liquids (usually water, sometimes combined with chemical additives) and a mechanical process to scrub soils, removes hazardous contaminants, and concentrates the contaminants into a smaller volume. The technology is used to treat a wide range of contaminants, such as metals, gasoline, fuel oils, and pesticides. Soil washing is a relatively low-cost alternative for separating waste and minimizing volume as necessary to facilitate subsequent treatment. It is often used in combination with other treatment technologies. The technology can be brought to the site, thereby eliminating the need to transport hazardous wastes.
Soil flushing, large volumes of water, at times supplemented with treatment compounds, are applied to the soil or injected into the groundwater to raise the water table into the zone of contaminated soil. Contaminants are leached into the groundwater, and the extraction fluids are recovered from the underlying aquifer. When possible, the fluids are recycled.
Final placement or destruction of toxic, radioactive, or other wastes; surplus or banned pesticides or other chemicals; polluted soils; and drums containing hazardous materials from removal actions or accidental releases. Disposal may be accomplished through use of approved secure landfills, surface impoundments, land farming, deep-well injection, or incineration.