CONCRETE MIXING TECHNIQUES TIPS TRICKS BASICS AND TUTORIALS

MIXING OF CONCRETE TUTORIALS
Links On Concrete Mixing Tips and Tutorials

Concrete is one of the most used materials in civil and structural construction. May it be a high rise building, or a bridge that carries a heavy load, even in simple household projects, concrete is used.

An important aspect on the design of such is the desire to have a good concrete mix. Below are links to articles that teaches basics and advance concrete mixing techniques.

How To Mix Concrete
Concrete is a mixture of cement, sand, gravel and water. Variations in the ratio of the ingredients produces a mix suitable for different jobs but we will be instructing you on a general puepose mix suitable for most garden tasks and shallow foundations not house foundations. Mix 1 part cement, 2 parts sand and 4 parts of gravel. What you use to measure the parts depends on how much concrete you need normally buckets are the best measure, one part being a level bucket full. Read more... 

The Perfect Concrete Mix Design
Is there such a thing as a Perfect Mix Design? If you are looking for one mix design recipe that will  work perfectly for every job and every application,  the answer is definitely "NO". However, there is a  right mix design for every job and every  application, and with the right knowledge and good  communication between a concrete contractor and  his supplier, you can find The Perfect Mix Design  for every one of your jobs. Read more...

High Strength Concrete Mix Design
The type of concrete generally with compressive strength of 6000psi (40MPa) or greater is called as HSC. We need high strength concrete in our modern infrastructures in order to put the concrete into service at much earlier stage, To build up high rise building by reducing column sizes and increasing available space or in case of long span bridges Now what is mix design? Although the American Concrete Institute (ACI) doesn't use the term, preferring mix proportioning. Read more...

Concrete Mix Evaluator
Concrete mix design is no longer just a recipe of  proportions of cement, sand, stone and water. Today the  concrete supplier is held responsible for the performance  of the in-place concrete. Curling, cracking, dusting, color variation, moisture  transmission, and strength, are all concerns for the quality of the in-place concrete.  Much  of what happens is outside the responsibility or control of the concrete producer.  Concrete of good quality can become undesirable in the hands of an inexperienced  finisher, but poor concrete, that of inappropriate proportions, will doom the final product  regardless of the experience of the concrete finisher. Read more...

How to Properly Mix Concrete
How to hand mix concrete so it delivers maximum strength and durability. Mixing isn't complicated and when done well, the concrete should last a lifetime. Mixing bags of concrete isn't complicated. You add some water, stir it up and pour it out. But to get the most strength from the concrete, you have to recognize when it has just the right amount of water mixed in. Too little water and the particles in the mix won't stick together. Too much water weakens the concrete. In this article, we'll show you what the perfect mix looks like. We'll also show you a mixing technique that will ensure thoroughly mixed concrete with a minimum of effort. Read more...

SHANLEY'S THEORY OF INELASTIC BUCKLING OF STEEL MEMBERS BASIC AND TUTORIALS

SHANLEY'S THEORY OF INELASTIC BUCKLING OF STEEL MEMBERS BASIC INFORMATION
What Is Shanley's Theory of Inelastic Buckling Of Steel Members?



Although the tangent modulus theory appears to be invalid for inelastic materials, careful experiments have shown that it leads to more accurate predictions than the apparently rigorous reduced modulus theory.

This paradox was resolved by Shanley [1], who reasoned that the tangent modulus theory is valid when buckling is accompanied by a simultaneous increase in the applied load (see Figure 3.8) of sufficient magnitude to prevent strain reversal in the member.

When this happens, all the bending stresses and strains are related by the tangent modulus of elasticity Et , the initial modulus E does not feature, and so the buckling load is equal to the tangent modulus value Ncr,t .

As the lateral deflection of the member increases as shown in Figure 3.8, the tangent modulus Et decreases (see Figure 3.6b) because of the increased axial and bending strains, and the post-buckling curve approaches a maximum load Nmax which defines the ultimate resistance of the member.

Also shown in Figure 3.8 is a post-buckling curve which commences at the reduced modulus load Ncr,r (at which buckling can take place without any increase in the load). The tangent modulus load Ncr,t is the lowest load at which buckling can begin, and the reduced modulus load Ncr,r is the highest load for which the member can remain straight.

It is theoretically possible for buckling to begin at any load between Ncr,t and Ncr,r . It can be seen that not only is the tangent modulus load more easily calculated, but it also provides a conservative estimate of the member resistance, and is in closer agreement with experimental results than the reduced modulus load.

For these reasons, the tangent modulus theory of inelastic buckling has gained wide acceptance.