Lecture on Brick Masonry
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This document discusses civil engineering materials related to brick masonry. It covers the manufacturing of bricks from clay or fly ash, the properties required for good brick clay and fly ash, the process of manufacturing bricks in clamps or kilns, the components and shapes of bricks used in masonry, and laboratory tests to determine the quality and strength of bricks.
Lecture on Brick Masonry
- 1. CVL3211 : Civil Engineering Materials Department of Civil Engineering Abhipsa Kar Pranjal Mandhaniya Rashmisikha Behera ITER, SoA University November 16, 2016 1 / 6
- 2. CVL3211 : Civil Engineering Materials Brick masonry Brick masonry This chapter will cover under given topics. Properties of brick clay and fly ash Manufacturing of brick Components of brick masonry Identification of good quality brick 2 / 6
- 3. CVL3211 : Civil Engineering Materials Properties of brick clay and fly ash Properties of brick clay and fly ash Brick are made from finely pulverized clayey soil or fly ash. Large grains or lumps will not fuse properly hence considered undesirable. Main constitutes of brick clay are: Silica (50-60%), Alumina (20-30%), Iron Oxides (5-6%), MgO (less than 5%), Lime (less than 5%). All the constitutes are not desirable though. Some ingridents like lime, alkalies, organic matter etc cause problems with brick. Fly ash bricks are manufectured by 45% fly ash and 55% cementing material (sand, stone dust, lime, gypsum). Fly ash bricks are lightweight, uniform, water/fire resistant and strong as compared to clay bricks. 3 / 6
- 4. CVL3211 : Civil Engineering Materials Manufacturing of brick Manufacturing of brick Bricks are manufactured either in clamps or kiln. Both have their pros and cons as given below. Factor Clamp burning Kiln burning Capacity 20000-100000 25000 Fuel cost Low i.e. grass, cow dung etc. High i.e. coal, electricity etc. Infrastructure Low (temporary structures) High (permanent kilns) Quality 60% of batch is good 90% of batch is good Fire regulation Unregulated (no control system) Regulated by fuel insertion and removal Conduction Time 2-6 months for one clamp Works 24×7 and 12 days for brick cooling 4 / 6
- 5. CVL3211 : Civil Engineering Materials Components of brick masonry Components of brick masonry Standard size of brick is 19 × 9 × 9 cm3. Frog is engraving on top face of brick required for cement joint connection in masonry and further engraving the brand name of manufacturer. Bricks used for masonry sometimes needed to be changed in shape in-situ. Even rounded angled brick are manufactured for curved walls e.g. bullnose and cownose bricks. For some joint applications, bricks are cut on-site e.g. king closer and queen closer. Generally, mortar used in brick masonry is cement mixed with sand in a 1:3 composition with water cement ratio of about 0.4-0.5. 5 / 6
- 6. CVL3211 : Civil Engineering Materials Laboratory test of brick Laboratory test of brick Different tests are used to determine quality of brick: Absorption test: After 24 hours of immersion in water, the water absorptions should not be more than 20% for clay bricks. Compressive Strength test: Brick should not break before 10MPa in compressive testing. Efflorescence: After 24 hours of immersion in water, salt deposition on brick surface should not be more than 10% of total surface area. Soundness: Two brick when struck with each other should make a clear metallic ringing sound. Hardness: If fingernail scratch does not cause any impression on brick, its sufficiently hard. All the above tests, if satisfied by a brick, define quality of a first class brick. 6 / 6