Ads
related to: rainproof concrete after pouring sand in soil solution to remove gas stains
Search results
Results From The WOW.Com Content Network
Degraded concrete and rusted, exposed reinforcement bar (rebar) on Welland River bridge of the Queen Elizabeth Way in Niagara Falls, Ontario. Concrete degradation may have many different causes. Concrete is mostly damaged by the corrosion of reinforcement bars due to the carbonatation of hardened cement paste or chloride attack under wet ...
Oxidation of pyrite in clay formations in contact with concrete – this produces sulfuric acid which reacts with concrete. Bacterial activity in sewers – anaerobic sulfate reduction at work in the organic-rich sludges accumulated under water in the conduits produces hydrogen sulfide gas (H 2 S).
Concrete sealers are applied to concrete to protect it from surface damage, corrosion, and staining. They either block the pores in the concrete to reduce absorption of water and salts or form an impermeable layer which prevents such materials from passing.
The cement industry is one of the main producers of carbon dioxide, a greenhouse gas. [2] Concrete causes damage to the most fertile layer of the earth, the topsoil. Concrete is used to create hard surfaces which contribute to surface runoff that may cause soil erosion, water pollution and flooding.
To attempt to simplify and to stylize a very complex set of various reactions, the whole ASR reaction, after its complete evolution (ageing process) in the presence of sufficient Ca 2+ cations available in solution, could be compared to the pozzolanic reaction which would be catalysed by the undesirable presence of excessive concentrations of alkali hydroxides (NaOH and KOH) in the concrete.
MICP has been shown to prolong concrete service life due to calcium carbonate precipitation. The calcium carbonate heals the concrete by solidifying on the cracked concrete surface, mimicking the process by which bone fractures in human body are healed by osteoblast cells that mineralize to reform the bone. [36]
Concrete waste that is rich in alkaline calcium compounds can be used to remove and recover various elements from an aqueous solution. Waste concrete has been used as a sorbent to remove phosphorus from wastewater after the removal of excess sludge in sewage treatment plants. [27] Concrete waste may also be used as an inexpensive gas treatment ...
Deep soil mixing requires specialized auger mixing equipment. In order to apply this method in-situ and in deep soil, the oxidant must be pumped to the point of mixing using a kelly bar (a piece of earth drilling equipment), or appropriate piping to the place where the soil needs to be oxidized. The soil then has to be mixed by using mixing blades.