tensile strength is approximately between .08 to .15 of compression strength in concrete
f ′c: concrete compressive strength at 28 days (compression is negative) fcu: concrete crushing strength (compression is negative)
if water increse stergth will reduce
The compressive strength of M25 concrete at 7 days will be between 6-7.5 N/mm2 .
Neither tensile strength nor compressive strength is inherently "stronger." Some materials are stronger in tension; other materials are stronger in compression. For example, rope is much stronger in tension than in compression, but concrete is much stronger in compression than in tension.
Cylindrical strength = 85% of Cube strength.
mortar are mixing by sand & cement and concrete is mixing by cement, sand & stone
In general, the more you compress the less you enhance.
The durability of concrete is its ability to resist weathering action, chemical attack, abrasion, or any process of deterioration. The strength of concrete is the ability of the concrete to withstand pressure or force.
Modulus of rupture > Splitting strength > Direct tensile strength
concrete grade and strength are both revalent since if grade increase setting time will be less and curing to be done propely so that concrete strength will reach higher. If concrete grade is low curing to done longer days upto intial setting time to reach proper strength
The span to depth ratio is in place preliminary as a method of ensuring deflections falls within certain limits. As concrete is a multi-phase material and does not behave linearly, it is often complex to calculate expected accurate deflections. codes set out given span/depth ratios as a simpler method or ensuring deflections remain in given limits. These ratios have been derived empirically from testing. The compressive strength of concrete as a material does not vary with varying span/depth. However, the amount of the concrete section which is in compression will vary with span and depth due to changes in the applied moment and increase/reduction of the internal lever arm.
A characteristic strength is the strength of the material used for design purpose, and is statistically defined by the lower 5% fractile of a bell curve. Compressive strength is a generic term that could refer to anything