Search results
Results from the WOW.Com Content Network
When it reacts with concrete, it causes the slab to expand, lifting, distorting and cracking as well as exerting a pressure onto the surrounding walls which can cause movements significantly weakening the structure. Some infill materials frequently encountered in building fondations and causing sulfate attack are the following: [2] Red Ash
Corrosion may occur where stale sewage generates hydrogen sulfide gas into an atmosphere containing oxygen gas and high relative humidity. There must be an underlying anaerobic aquatic habitat containing sulfates and an overlying aerobic aquatic habitat separated by a gas phase containing both oxygen and hydrogen sulfide at concentrations in excess of 2 ppm.
Example of flat piece of concrete having dislodged with corroded rebar underneath, Welland River bridge across Queen Elizabeth Way in Niagara Falls, Ontario. The expansion of the corrosion products (iron oxides) of carbon steel reinforcement structures may induce internal mechanical stress (tensile stress) that cause the formation of cracks and disrupt the concrete structure.
The drain system is simple in form: It's made up of trenches filled with gravel or rock that contain a perforated pipe that reroutes water away from problem areas. "The drain operates by allowing ...
DPC visible between concrete foundation and brickwork. Damp proofing is defined by the American Society for Testing and Materials (ASTM) as a material that resists the passage of water with no hydrostatic pressure. [1] Waterproof is defined by the ASTM as a treatment that resists the passage of water under pressure. [1]
Much agricultural pollution is exacerbated by surface runoff, leading to a number of down stream impacts, including nutrient pollution that causes eutrophication. In addition to causing water erosion and pollution, surface runoff in urban areas is a primary cause of urban flooding , which can result in property damage, damp and mold in ...
Concrete will need to be poured to surround the trench drain so that the load can be transferred from the channel and grate to the surrounding areas. Pre-cast trench drains generally come in 4-inch (100 mm) widths but can range anywhere from a 1.75-inch (44 mm) slot to 2-inch (51 mm) wide channels with grates, and up to any size imaginable ...
Concrete has a total embodied energy of 1.69 GJ/tonne, lower per unit mass than most common building materials besides wood. However, concrete structures often have high masses, so this comparison is not always directly relevant to decision making. Additionally, this value is based only on mix proportions of up to 20% fly ash.