Friday, April 5, 2013

Heat of Hydration in Concrete Mixture

for aqueous ionic solutions,
• Solvent attractive forces and Mixing forces are
combined into a term called the heat of hydration
∆Hsolvent + ∆Hmix = ∆hhydration
 attractive forces in water = H-bonds
 attractive forces between ion and water = ion-dipole
 ∆Hhydration = heat released when 1 mole of gaseous ions
dissolves in water
 ∆Hsolute = - ∆Hlatic

Heat of Hydration
The term ‘heat of hydration’ is applied to the heat generated by the chemical reactions, which occur in setting concrete between the water and cement. The heat causes the concrete first to expand and then to shrink as it cools. If there is a temperature gradient across the concrete or the concrete is otherwise restrained, cracking may occur. The two factors, which are most likely to cause excessive generation of heat, are very large pours and high cement contents. Some specifications set a maximum cement content in order to limit the generation of heat.

erfc

http://office.microsoft.com/en-us/excel-help/erfc-HP005209078.aspx

Doing some note taking on erfc for Water Resource Engineer home work assignment.

Monday, January 28, 2013

Friday, January 25, 2013

Ponicare

http://www.math.unl.edu/~mbrittenham2/ldt/poincare.html

Friday, January 18, 2013

Hooke's Law

The Curious Life of Robert Hooke: The Man Who Measured LondonThe Curious Life of Robert Hooke: The Man Who Measured London by Lisa Jardine






Why I want to read this book:  First encounter Hooke's law in general physics class.  We conducted experiments using springs and weights in parallel and in circuits.  Then this same equation was inverse in circuitry for electricity and magnetism.  Then in the strength of materials class his law for elastic material increased my interests.  After picking up this book at the local library, I saw an article about a new material using Hooke's Law and principals to absorb the energy of exploding bomb.  They have figured out how to make really thin clear membrane embedded in glass to create bullet proof glass using Hooke's Law.  Hooke also dabbled in architecture helping Sir Christopher Wren build London after the Great Fires.     



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