Study the following statements:I. For constant w/c ratio, finer sand ...
For a constant water/cementitious material ratio, an increase in the aggregate/cementitious material ratio will decrease workability; more cementitious material is needed when finer aggregate gradings are used. A fine aggregate deficiency results in a mixture that is harsh, prone to segregation, and difficult to finish. On the contrary, an excess of fine aggregate will lead to more permeable and less economical concrete, although the mixture will be easily workable.
Hence the correct answer is option C.
View all questions of this test
Study the following statements:I. For constant w/c ratio, finer sand ...
Explanation:
I. For constant w/c ratio, finer sand decreases the workability.
- Workability refers to the ease with which concrete can be mixed, transported, placed, and compacted.
- The water-cement ratio (w/c ratio) is a key factor in determining the workability of concrete. A lower w/c ratio results in lower workability, while a higher w/c ratio results in higher workability.
- Finer sand particles have a larger surface area per unit volume, which can absorb more water and result in a lower effective w/c ratio. This can lead to a decrease in workability, as the concrete may become more difficult to mix, transport, place, and compact.
II. Creep is the deformation of concrete under sustained loading.
- Creep is a time-dependent deformation that occurs in concrete under sustained loading. It is a result of the continued application of stress over a long period of time, causing the concrete to slowly deform and change shape.
- Creep can be a significant factor in the design of concrete structures, as it can lead to long-term deformation and cracking if not properly accounted for.
- Creep can be affected by a number of factors, including the age and strength of the concrete, the type and amount of aggregate used, and the environmental conditions in which the concrete is placed and cured.
Conclusion:
Both statements are correct and relevant to the properties and behavior of concrete. Statement I relates to the workability of concrete and how it can be affected by the size and shape of the aggregate used, while Statement II relates to the long-term deformation of concrete under sustained loading.