BBC Notes U2 - Stone and Brick Masonry Construction PDF

**Unit II: Stone and Brick Masonry Construction** **Stone Masonry** 1. **Technical Terms in Stone Masonry** Stone masonry refers to the construction of buildings or structures using stones as the primary material. The stones are cut and shaped, or used in their natural form, to create walls, arc...

**Unit II: Stone and Brick Masonry Construction** **Stone Masonry** 1. **Technical Terms in Stone Masonry** Stone masonry refers to the construction of buildings or structures using stones as the primary material. The stones are cut and shaped, or used in their natural form, to create walls, arches, columns, and other structural elements. - **Ashlar Masonry**: Stone masonry where the stones are finely dressed and laid in horizontal courses with very thin mortar joints. - **Rubble Masonry**: Stone masonry where stones are rough and irregular in shape, often laid without much dressing. The mortar joints are larger compared to ashlar masonry. - **Quoins**: The corner stones of a masonry wall, usually larger and more decorative than the others. - **Coursed Masonry**: Masonry where stones are laid in horizontal layers or courses of uniform thickness. - **Random Rubble Masonry**: Masonry where stones of irregular sizes are laid without any attempt at uniformity in the courses. **2. General Principles to Be Observed During Construction** Stone masonry requires careful planning and execution to ensure durability, strength, and stability. The following principles should be observed during construction: - **Selection of Stone**: The choice of stone is critical to the performance of the masonry. Stones should be durable, strong, and resistant to weathering. Ideally, stones should have a uniform texture and not contain harmful elements like salts that can cause degradation. - **Stone Preparation**: Stones should be properly dressed and cut to the required dimensions. This includes dressing the stones to achieve an even surface to allow better bonding with mortar and to create uniform courses. - **Mortar**: The mortar used in stone masonry should be strong enough to hold the stones in place but flexible enough to allow for small adjustments. Mortar is typically made from a mixture of sand, lime, and cement, depending on the type of stone and the environmental conditions. - **Bonding and Jointing**: Stones should be laid with adequate bonding between them to ensure the stability of the wall. Mortar joints should be kept as thin as possible, ideally around 6-10 mm, to reduce water penetration and improve the appearance of the masonry. - **Course Leveling**: The courses of stones should be leveled to maintain uniformity in the height of each course. Horizontal and vertical alignment should be checked regularly during construction to avoid any distortion in the finished structure. - **Curing**: After laying the stones and applying mortar, it is essential to cure the masonry by keeping it moist for a specified time. This helps the mortar set properly and increases the strength of the stonework. - **Thickness of Walls**: The thickness of the stone walls depends on the size and weight of the stones, as well as the structural requirements of the building. Typically, load-bearing walls will be thicker than partition walls. **3. Selection of Stone for Masonry** The selection of stone depends on several factors, including the type of construction, environmental conditions, and budget. Some key considerations are: - **Strength**: The stone should be strong enough to bear the load of the structure. - **Durability**: The stone should resist weathering and wear over time, especially in regions with extreme weather conditions. - **Workability**: The stone should be easy to cut and shape, depending on the design requirements. - **Cost**: Availability and cost of transportation may influence the selection of stone. - **Aesthetic Qualities**: The stone should have an aesthetic appeal and be suitable for the intended design of the building. **Brick Masonry Construction** **1. Technical Terms in Brick Masonry** Brick masonry involves the use of bricks (typically made from clay, concrete, or stone) to create walls, floors, and other structural elements. Bricks are bound together with mortar. - **Course**: A horizontal layer of bricks. - **Bed**: The surface of the brick that is laid on the mortar bed. - **Perpendicular Joint**: The joint that is perpendicular to the bed and faces out from the wall. - **Header**: A brick laid with its shorter end exposed on the surface of the wall. - **Stretcher**: A brick laid with its longer side exposed, running parallel to the face of the wall. - **Bond**: The arrangement of bricks in a masonry wall to ensure strength and stability. Different types of bonds provide various aesthetic and structural properties. **2. General Principles to Be Observed During Construction** When constructing brick masonry, there are several essential principles to follow for ensuring the strength, durability, and efficiency of the structure: - **Selection of Bricks**: Bricks should be of uniform size, well-burned, and free from cracks or defects. They should have the proper compressive strength for the intended use. Good-quality bricks will have a uniform color and smooth texture. - **Mortar**: The mortar used in brick masonry must be of the correct mix, providing sufficient bonding strength while also allowing for flexibility in case of minor movements in the building. - **Laying of Bricks**: Bricks should be laid on the mortar bed with staggered joints to ensure a strong bond between them. The joints should be filled completely with mortar to avoid voids, which could weaken the structure. - **Alignment**: The bricks should be laid in such a way that the walls are plumb, and the courses are level. This ensures the structural stability and aesthetic appearance of the building. - **Curing**: After laying the bricks, curing is essential to help the mortar gain strength. The masonry should be kept moist for a period to ensure the mortar hardens correctly and achieves the desired bonding strength. - **Wall Thickness**: The thickness of the brick walls varies depending on their use. Load-bearing walls typically have a greater thickness, while non-load-bearing walls may be thinner. - **Cleaning**: Any excess mortar or debris should be cleaned off the surface of the bricks to maintain the appearance of the masonry and avoid weakening the mortar joints. 2. **Commonly Used Types of Bonds** 3.  The bond refers to the arrangement of bricks in a pattern to provide strength, stability, and aesthetic appeal to brickwork. Common types of bonds include: - **Stretcher Bond**: This is the simplest and most common brick bond, where bricks are laid with the long face exposed (stretchers). The bricks are laid in rows, with each row offset from the one below it. It is primarily used for non-load-bearing walls and partitions. - **Suitability**: Ideal for simple walls or partition walls where the brickwork is not intended to bear significant loads. - **Header Bond**: In this bond, the bricks are laid with their short faces exposed (headers), creating a stronger bond as the bricks interlock more firmly. This bond is used less frequently than the stretcher bond. - **Suitability**: Suitable for walls that require higher strength, often used in boundary walls or in cases where bricks need to interlock more securely. - **English Bond**: One of the strongest and most durable brick bonds, where each course alternates between stretchers and headers. This bond ensures that the wall has interlocking bricks, providing superior strength and stability. - **Suitability**: Often used in load-bearing walls and structural masonry where strength and durability are crucial. It is ideal for thick walls and buildings subjected to heavy loads. - **Flemish Bond**: This bond alternates between stretchers and headers in each course, with each brick having a header and a stretcher on alternate courses. The headers are placed in the middle of the wall, giving it a distinctive pattern. This bond is highly decorative and is commonly used in exposed brickwork. - **Suitability**: Often used for aesthetic purposes in decorative walls, such as facades or when both strength and appearance are important. **4. Suitability of Bonds** - **Stretcher Bond**: Economical for non-load-bearing walls, provides simplicity in construction. - **Header Bond**: Provides good strength, useful in non-load-bearing applications or when increased interlocking is required. - **English Bond**: Best for load-bearing walls due to its interlocking structure, making it strong and durable. - **Flemish Bond**: Aesthetically pleasing and suitable for external facades and areas where both strength and appearance are important. **Conclusion** Both stone and brick masonry play essential roles in construction, each offering distinct advantages. Stone masonry is particularly beneficial in creating long-lasting, durable structures, while brick masonry provides versatility, ease of construction, and aesthetic value. Understanding the technical terms, construction principles, and types of bonds in brick masonry enables better design, stronger structures, and more efficient building processes.