Proportion of Ingredients in Concrete

The proportion of ingredients in concrete is a crucial aspect that affects its strength, durability, and workability. The correct proportion of ingredients is determined by several factors, including:

1. Bulking of Sand
The bulking of sand refers to an increase in the volume of sand due to the presence of moisture. This increase in volume can affect the proportion of sand in the concrete mix, leading to a reduction in its strength. Therefore, the correct proportion of sand should be determined based on its dry density rather than its volume.

2. Water Content
The water content of the concrete mix is another crucial factor that affects its strength and workability. The correct proportion of water is determined based on the water-cement ratio, which is the ratio of the weight of water to the weight of cement in the mix. A higher water-cement ratio leads to a weaker and more workable concrete, while a lower water-cement ratio leads to a stronger but less workable concrete.

3. Absorption and Workability
The absorption and workability of the aggregates used in the concrete mix also affect its strength and workability. Aggregates with high absorption rates can lead to a higher water-cement ratio, which weakens the concrete. Similarly, aggregates with poor workability can make it difficult to achieve a homogenous mix, leading to weak spots in the concrete.

Conclusion
In conclusion, the correct proportion of ingredients in concrete depends on several factors, including the bulking of sand, water content, absorption, and workability of the aggregates used. Therefore, it is crucial to carefully consider these factors when mixing concrete to ensure that it meets the required strength and durability standards.

Right answer is d