Pick up the correct statement from the following: A. For thin structures subjected to wetting and drying, the water cement ratio should be 0.45 B. For mass concrete structures subjected to wetting and drying, the water ratio should be 0.55 C. For thin structures which remain continuously under water, the water-cement ratio by weight should be 0.55 D. All the above

The correct answer is D. All of the above.

The water-cement ratio is the ratio of the weight of water to the weight of cement in a concrete mix. It is one of the most important factors in determining the strength and durability of concrete.

For thin structures subjected to wetting and drying, a

For mass concrete structures subjected to wetting and drying, a water-cement ratio of 0.55 is recommended. This will help to reduce the risk of cracking and ensure that the concrete remains strong.

For thin structures which remain continuously under water, a water-cement ratio of 0.55 is recommended. This will help to prevent the concrete from deteriorating.

It is important to note that the water-cement ratio is just one of the factors that affect the strength and durability of concrete. Other factors include the type of cement used, the aggregate used, the mix proportions, and the curing method.