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The mix design for M35 Grade Of Concrete for pile foundations provided here is for reference purpose only. Actual site conditions vary and thus this should be adjusted as per the location and other factors.
Grade of Concrete : M35
Characteristic Strength (Fck) : 35 Mpa
Standard Deviation : 1.91 Mpa*
Target Mean Strength : T.M.S.= Fck +1.65 x S.D.
(from I.S 456-2000) = 35+ 1.65×1.91
= 38.15 Mpa
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A long time used material in concrete is for the first time fully replaced by a nano material.It is well known in physics and chemistry that a well designed and developed nano material produces better and cheaper cost results than traditional materials, thanks to the stabilization and reinforcement of matter properties at this level: a thousand fold smaller than the older level: “micro” (0.000001 mt).
Micro silica has been one of the world’s most widely used products for concrete for over eighty years. Its properties allowed high compressive strength concretes; water and chemical resistant concretes, and they have been part of many concrete buildings that we see nowadays. Its disadvantage, though, has been its relatively high cost and contamination, which affects the environment and the operators’ health. As micro silica, as a powder, is thousand fold thinner than cigarette smoke. Operators must take special precautions to avoid inhaling micro silica and not to acquire silicosis, an irreversible disease.
Filler materials are gaining widespread popularity and becoming very important because they help in increasing some of the mix properties and also lower the usage of binder which is usually more expensive
Here is the table showing some common filler materials along with binders
The ACI Code gives approximate formulas for finding shear and bending moments in continuous beams and one way slabs. A summary list of these formulas follows. They are equally applicable to USCS and SI units. Refer to the ACI Code for specific applications of these formulas.
For Positive Moment
1 ) End spans
If discontinues end is unrestrained = wl2n /11
If discontinues end is integral with the support= wl2n /14
American Society for Testing and Materials (ASTM) specifications cover renforcing steel. The most important proper- ties of reinforcing steel are
1. Modulus of elasticity E s , lb/in 2 (MPa)
2. Tensile strength, lb/in 2 (MPa)
The tensile strength of concrete is used in combined-stress design. In normal-weight, normal-density concrete the tensile strength can be found from
The modulus of elasticity of concrete E c adopted in modified form by the ACI Code can be calculated by the formula given below:
A trial batch of concrete can be tested to determine how much concrete is to be delivered by the job mix. To determine the volume obtained for the job, add the absolute volume V a of the four components—cements, gravel, sand, and water.
Find the V a for each component from
V a = W L / ( SG ) W u
where V a = absolute volume, ft 3 (m 3 )
The water / cementitious (w/c) ratio is used in both tensile and compressive strength analyses of Portland concrete cement. This ratio is found from
w / c = w m / w c
where w m = weight of mixing water in batch, lb (kg); and w c = weight of cementitious materials in batch, lb (kg).
By Kelly Baldwin
Published in Construction
Abstract: Conductive concrete is a cement-based composite that contains electronically conductive components to attain stable and relatively high conductivity. Potential applications include electrical heating for de-icing of parking garages, sidewalks, driveways, highway bridges, and airport runways, as well as electrical grounding.
Résumé: Le béton conducteur est un composite à base de ciment contenant une certaine quantité d’éléments qui assurent une conductivité électrique stable et relativement élevée. Les applications possibles sont : le chauffage électrique pour dégivrer les garages de stationnement, les trottoirs, les voies d’accès, les ponts routiers et les pistes d’aéroport, et la mise à la terre électrique.
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