Final setting time of cement should not be more than:

To determine the setting time of cement, we must first comprehend its composition and physical characteristics. A powdery material is produced by calcining lime and clay, as is well known. Then mortar is created by combining it with water. If not, it is combined with water, sand, and gravel to make concrete.

As is common knowledge, cement hardens when it comes into touch with water. Crystallization is the process by which cement becomes more durable. Interlocking crystals are created during the process. After that, lime and water are added to the recovered fly ash mixture. As a result, it creates cement, a substance with a stellar reputation for strength and durability. This fly concrete ash with a large volume can replace more than 25% of the cement. Additionally, it aids in lowering the quantity of pollutants produced during the mixing of concrete.

When cement is first put, the cement's first setting time exceeds 45 minutes. This much time is enough for the concrete to be transported and placed on the floor before it begins to settle. After then, the cement should settle in less than 375 minutes as its ultimate setting time. because 10.25 hours are equivalent to 375 minutes. Therefore, it will take more than 10 hours for cement to reach its ultimate setting time.

Hence, option d is correct.