Search results
Results From The WOW.Com Content Network
According to a 1996 study by H. L. Erlich in Chemical Geology journal, the self-healing ability of concrete has been improved by the incorporation of bacteria, which can induce calcium carbonate precipitation through their metabolic activity. [111] These precipitates can build up and form an effective seal against crack related water ingress.
Limestone generated inside the matrix of concrete may result in the densification of the matrix by pore filling and can help to self-heal crack, reducing its (water) permeability and resulting in the recovery of lost strength. If circumstances are favorable, most bacteria can precipitate CaCO 3 from the solution. [30]
In poured concrete foundations, cracks and pipe penetrations are the most common entry points for seepage. These openings can be sealed from the interior. Epoxies , which are strong adhesives, or urethanes can be pressure injected into the openings, thus penetrating the foundation through to the exterior and cutting off the path of the seepage.
Gaps between damp course for damp to rise in jerry-built house - Helps To Health, Sir Henry Burdett (1885), page 124. Henry Burdett was deeply concerned with the quality building in Victorian England, and he cautioned would-be house buyers to check houses for the presence of a damp-proof course and to ensure that it is of an effective type.
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.
As bacteria often prefer to adhere to the surfaces of solids than to remain into suspension in water (planktonic bacteria), the biofilms formed by sessile (i.e., fixed) bacteria are often the place where they are the most active. Biofilms made of multiple layers (like an onion) of dead and living bacteria protect the living ones from the harsh ...
Get AOL Mail for FREE! Manage your email like never before with travel, photo & document views. Personalize your inbox with themes & tabs. You've Got Mail!
Bacteria will respond to substances secreted by plant roots and optimize nutrient acquisition for the plant with their own metabolic processes. Though dependent on the strain, most Rhizobacteria will produce major phytohormones such as auxins, gibberellins, cytokinins, abscisic acid (ABA) and ethylene, which stimulate plant growth and increase ...