Civil Engineering - Building Materials - Discussion

As the material is thin it will not require much water, even in dry as well in wet condition because it will have the tendency to fulfill its water requirement, but in case of mass concrete it will need enough water for its hydration whether in dry or wet condition, its because it is thick.

Why massive concrete structures which remain continuously under water w/c ratio is high as compare to drying & wetting concrete structure?

Can any one keep reference for above mentioned W/C ratios?

On high workability it easy to work on those concrete. So we use more water cement like 0.55 or 0.65.

In water, the thin like structure require 0.55 wc ratio. Why it is increasing in water every structure will given high wc ratio from a supposed one.

The reaction of cement with water is exothermic and releases lot of heat. This heat is very high in case of mass concrete structures which in turn results in failure.

So high W/C ratio is used for both workability during construction and serviceability during operation.

AS W/C Ratio increases strength decreases right then how can we use those high ratios at important places ?

The cement:mortar ratio is important in prac engineering work because cement features, precast or not, need a specific ratio to suit its specific function. Say for instance you're building a brick wall which has an opening; your c:m ratio (the first number represents one "part" cement in my country, and the latter represents aggregates such as sand, stones etc) between the bricks which a situated above the opening must be in such a way that it is stronger than the cm of the surrounding bricks.

The water-cement ratio is a measure of the amount of water used in a concrete mixture relative to the amount of cement. The water-cement ratio is important because it affects the strength, durability, and workability of the concrete. Different types of structures and environments may require different water-cement ratios to achieve optimal results.

For thin structures subjected to wetting and drying, such as walls and bridges, the water-cement ratio should be around 0.45. For mass concrete structures subjected to wetting and drying, such as dams and foundations, the water-cement ratio should be around 0.55.

For thin structures that remain continuously under water, such as slabs and beams, the water-cement ratio should be around 0.55. For massive concrete structures that remain continuously under water, such as piers and abutments, the water-cement ratio should be around 0.65.

Strength of concrete primarily depends upon the strength of cement paste. Strength of cement paste depends upon the dilution of paste or in other words, the strength of paste increases with cement content and decreases with air and water content.