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  2. Structural stability - Wikipedia

    en.wikipedia.org/wiki/Structural_stability

    Structural stability of the system provides a justification for applying the qualitative theory of dynamical systems to analysis of concrete physical systems. The idea of such qualitative analysis goes back to the work of Henri Poincaré on the three-body problem in celestial mechanics .

  3. Carbanion - Wikipedia

    en.wikipedia.org/wiki/Carbanion

    Formally, a carbanion is the conjugate base of a carbon acid: R 3 CH + B − → R 3 C − + HB. where B stands for the base. The carbanions formed from deprotonation of alkanes (at an sp 3 carbon), alkenes (at an sp 2 carbon), arenes (at an sp 2 carbon), and alkynes (at an sp carbon) are known as alkyl, alkenyl , aryl, and alkynyl anions ...

  4. Phosphonate - Wikipedia

    en.wikipedia.org/wiki/Phosphonate

    Superplasticizers are concrete admixtures designed to increase the concrete fluidity and workability of concrete or to decrease its water-to-cement (w/c) ratio. By reducing the water content in concrete, it decreases its porosity, improving so the mechanical properties (compressive and tensile strength) and the durability of concrete (lower ...

  5. File:Carbanion Structural Formulae V.1.svg - Wikipedia

    en.wikipedia.org/wiki/File:Carbanion_Structural...

    The following other wikis use this file: Usage on ar.wikipedia.org أنيون كربوني; Usage on be.wikipedia.org Карбаніён; Usage on ca.wikipedia.org

  6. Properties of concrete - Wikipedia

    en.wikipedia.org/wiki/Properties_of_concrete

    Concrete has a very low coefficient of thermal expansion, and as it matures concrete shrinks. All concrete structures will crack to some extent, due to shrinkage and tension. Concrete which is subjected to long-duration forces is prone to creep. The density of concrete varies, but is around 2,400 kilograms per cubic metre (150 lb/cu ft). [1]

  7. Concrete degradation - Wikipedia

    en.wikipedia.org/wiki/Concrete_degradation

    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.

  8. Concrete - Wikipedia

    en.wikipedia.org/wiki/Concrete

    Concrete is a composite material composed of aggregate bonded together with a fluid cement that cures to a solid over time. Concrete is the second-most-used substance in the world after water, [1] and is the most widely used building material. [2] Its usage worldwide, ton for ton, is twice that of steel, wood, plastics, and aluminium combined. [3]

  9. Limit state design - Wikipedia

    en.wikipedia.org/wiki/Limit_state_design

    A clear distinction is made between the ultimate state (US) and the ultimate limit state (ULS). The Ultimate State is a physical situation that involves either excessive deformations leading and approaching collapse of the component under consideration or the structure as a whole, as relevant, or deformations exceeding pre-agreed values.