Question

The function of sand in mortar is (1) to decreasc the hardncss (2) to make the mass compact (3) to decrease the plasticity of the mass (4) to prevent the excess shrinkage becausc of which cracks may be result

Short answer

The function of sand in mortar is to prevent excessive shrinkage, so the correct answer is (4).

Step-by-step solution

Understanding the role of sand in mortar

Consider what sand does when mixed with cement to form mortar. Think about its effect on the physical properties of the mixture such as hardness, compactness, plasticity, and shrinkage.

Analyze each given option

Evaluate options (1) to (4) based on the known effects of sand in mortar. Recall that sand helps to prevent excessive shrinkage, increase the overall volume, thus filling larger gaps and making the mass more compact.

Eliminate incorrect options

Consider options one by one. Option (1) is incorrect as sand actually increases the hardness when combined with cement. Option (2) is correct because sand contributes to making the mortar mass more compact. Option (3) is incorrect because sand reduces plasticity. Option (4) correctly identifies that sand prevents excess shrinkage.

Choose the best fitting answer

Among the analyzed options, the primary function of sand in mortar is to prevent excess shrinkage which can cause cracks. Hence, option (4) is the most appropriate answer.

Key concepts

construction materials

Construction materials are the backbone of any building project. Mortar is a key component used to bind bricks, stones, and other masonry units together. One of the primary ingredients in mortar is sand. Sand plays a crucial role in determining the final properties of the mortar.

Using appropriate construction materials, like sand in mortar, ensures the structural integrity and durability of the building. High-quality materials help to avoid issues like cracking and crumbling over time.

Understanding the role of each ingredient in construction materials is essential for ensuring the success of any building project.

mortar properties

Mortar properties are influenced by its ingredients, with sand being a significant component. Sand affects various physical properties of mortar:

• Hardness: Sand increases the hardness of the mortar, making it more durable.
• Compactness: Sand helps fill gaps between bricks or stones, making the mass more compact and strong.
• Plasticity: Adding sand reduces the plasticity (or workability) of the mortar. A less plastic mass is more stable and less prone to deformation.
• Shrinkage Prevention: One of the most important functions of sand in mortar is to prevent excess shrinkage. This minimizes the risk of cracks forming in the structure.

To achieve these properties, it's crucial to use the right proportion of sand in the mortar mix. This ensures the mortar performs as expected.

shrinkage prevention

Shrinkage prevention is a key concern in construction to maintain the structural integrity of a building.

Sand in mortar helps in reducing shrinkage caused by the drying and hardening of the cement paste. Excessive shrinkage can lead to cracks, weakening the structure.

Properly balanced mortar with sand ensures:

• Minimization of cracks and voids in masonry work.
• Increased stability and strength of the construction.

Using sand effectively mitigates the risk of shrinkage-related issues, contributing to the longevity of the building.

engineering entrance exam

Engineering entrance exams, such as JEE and others, often test knowledge on construction materials and their properties. Understanding the function of sand in mortar is a common topic.

Students preparing for these exams should focus on key concepts like:

• The role of sand in improving hardness and compactness.
• Understanding how sand contributes to the reduction of plasticity.
• Knowing how sand prevents shrinkage and why this is important for preventing cracks.

A solid grasp of these points can help in answering multiple-choice questions accurately, thereby boosting scores in the construction materials section of the exam.