The correct answer is A. 1 : 1.
Lime-sand mortar is a mixture of lime, sand, and water that is used to bind bricks together. The ratio of lime to sand can vary depending on the desired strength and durability of the mortar. A 1:1 ratio is a common choice for brick construction, as it provides a good balance of strength and workability.
Option B, 1:2, would result in a weaker mortar that is more likely to crack or crumble. Option C, 1:3, would result in a stronger mortar, but it would be more difficult to work with. Option D, 1:4, would result in a very strong mortar, but it would be very difficult to work with and would require a significant amount of time to set.
In addition to the ratio of lime to sand, the type of lime and sand used can also affect the properties of the mortar. Hydrated lime is a common
choice for brick construction, as it is easy to work with and provides good strength and durability. However, it can be more expensive than other types of lime. Quicklime is less expensive than hydrated lime, but it is more difficult to work with and requires more time to set. Sand should be clean and free of impurities, such as clay or silt.The water content of the mortar can also affect its properties. A too-dry mortar will be difficult to work with and may not bond well to the bricks. A too-wet mortar will be weak and may crumble. The ideal water content will vary depending on the type of lime, sand, and bricks being used.
The mortar should be mixed thoroughly to ensure that all of the ingredients are evenly distributed. It should be applied to the bricks in a thin layer, and the bricks should be pressed together firmly to ensure a good bond. The mortar should be allowed to set for at least 24 hours before any weight is placed on it.