Last Updated:13 December 2017 © LMS SEGi education

Last Updated:13 December 2017 © LMS SEGi education group 1 CE1205 CONSTRUCTION MATERIALS WEEK 14 Chapter 9 BRICKS AND BLOCKS PowerPoint® Slides by Salmaliza Salleh

Last Updated:13 December 2017 © LMS SEGi education group 2 Chapter Overview Chapter 9 exposed you the various properties and types of bricks and blocks.

Last Updated:13 December 2017 © LMS SEGi education group 3 To highlight the various properties and types of bricks and blocks. Learning Objectives

Last Updated:13 December 2017 © LMS SEGi education group 4 Learning Outcomes On completion, students should able to explain the properties of bricks and blocks and to list down different types of bricks and blocks.

Last Updated:13 December 2017 © LMS SEGi education group 5 1. Introduction Bricks are solid masonry units composed of inorganic non-metallic materials hardened or burned by heat or chemical action. Bricks are commonly used as partition walls, claddings and facings, perimeter and garden walls, and pavings and floorings. Bricks can also serve as external and internal load bearing wall or load bearing piers and column. Bricks are cheaper and faster in construction of structural components in buildings. It eliminates costly formwork and reinforcing steel. Examples: Clay-bricks, Calcium-Silicate bricks, Sand-Cement bricks, & Engineering bricks.

Last Updated:13 December 2017 © LMS SEGi education group 6 2. Clay Bricks Materials used for clay bricks range from soft & plastic surface deposits to hard mudstone, shales and slate. There are varieties of clay bricks which can be divided into three forms: 1. _____________ For general building works, widely used for foundations. Ideal backing for rendering, plaster & colour wash. 2. __________ Specially made or selected to give an attractive appearance when used without rendering or plaster or other surface treatment of the wall. 3. ______________ Must possess both the required strength & absorption properties.

Last Updated:13 December 2017 © LMS SEGi education group 7 BS 3921:1985 recognizes three qualities of bricks and they are: ___________ quality: the bricks suitable for internal use only. ___________ quality: Durable in the external face of the building. _________ quality: Bricks which are durable even when used in extreme exposure such as become saturated or frozen, e.g. retaining walls & sewerage plants.

Last Updated:13 December 2017 © LMS SEGi education group 8 There are five different types of bricks according to their physical shapes: Solid Perforated Hollow Cellular Special shapes (e.g. squints, radial, bullnose) www.kehaimachine.com

Last Updated:13 December 2017 © LMS SEGi education group 9 Hollow brick: A brick with a hole (or holes) through it in the long direction. It has almost the strength of a solid brick, but is lighter. The disadvantage is the open end. Cellular brick: A brick or block in which holes, closed at one end, exceed 20% of the volume. Perforated brick: 30-40% perforation on area of facing. Each perforation area not to exceed 50 mm square.

Last Updated:13 December 2017 © LMS SEGi education group 10 Properties of Clay bricks: Water absorption, porosity & suction: - depend on clay composition and duration & temperature of firing. Density: 2250 to 2800 kg/m3 Compressive strength: - decreases with increasing porosity and is influenced by clay composition and firing. Resistance to chemical attack: very resistant to alkalis acids, can counter chemicals. Behaviour under fire conditions: excellent

Last Updated:13 December 2017 © LMS SEGi education group 11 3. Calcium Silicate Bricks The raw materials used in the manufacture of Calcium Silicate bricks are ______________ aggregates, high __________ lime and water. Have broadly similar functional appearance and economic properties to clay bricks. Are used for wide range of loadbearing and non-loadbearing structures. Except class 1, they are resistant to attack by sulphate salts in soil & ground water. Have sharper arises & corners, and smoother faces compared to clay bricks.

Last Updated:13 December 2017 © LMS SEGi education group 12 Advantages of Calcium Silicate Bricks Beauty - In their natural state, Calcium Silicate Bricks are _________; a whiteness that remains even through years of weathering. High Compressive Strength Heat Resistance Sound Insulation Durability - Calcium Silicate Bricks harden with age. As they do not contain soluble salts, they do not effloresce or ________________.

Last Updated:13 December 2017 © LMS SEGi education group 13 4. Sand-Cement Bricks The main material for production of this brick is Portland ___________ and _____. BS1180: Nov.:1972 deals with the minimum requirements for these bricks, its classification, materials, dimensions, curing, compressive strength and drying shrinkage.

Last Updated:13 December 2017 © LMS SEGi education group 14 5.0 Engineering Bricks Very hard, dense, and strong. Normally ____________ and absorb very little moisture and usually used for load bearing members. They have excellent resistance to ________ and to _______, making them ideal for groundworks, sewer works and retaining walls. Developed in respond to the demand for structural material with very ________________ capacity. The strength and absorption of Engineering bricks can be referred to BS 3921:1985.

Last Updated:13 December 2017 © LMS SEGi education group 15 6.0 Brick Dimensions and Size The ‘__________ size’ is the actual size of brick with allowances for manufacturing tolerances. e.g. 215 x 102.5 x 65 mm The ‘__________ size’ is the actual size plus the thickness of the mortar joints. (+10mm) e.g. 225 x 112.5 x 75 mm Manufacturers are also able to supply alternative sizes and special shapes. 102.5 65 215

Last Updated:13 December 2017 © LMS SEGi education group 16 The sketches show the terms applied to brick position:

Last Updated:13 December 2017 © LMS SEGi education group 17 7.0 Manufacturing Process Basic principles: Raw material won (taken) from ground, e.g. quarries, holes, pit. Prepared and formed into desired shape. Burnt in a kiln to produce a tough and immensely durable bricks.

Last Updated:13 December 2017 © LMS SEGi education group 18 There are five methods of making clay bricks: The ___________ process, for plastic clays The __________ process. Mainly for colliery shales and certain other shales and clays which do not easily develop a high degree of plasticity. The _____________ press process, for the manufacture of bricks from clays and shales with low natural plasticity. The ______________ process. _______________.

Last Updated:13 December 2017 © LMS SEGi education group 19 Wire-Cut Process 1) raw material fed to the preparation plant 2) 1st stage – elimination of crushing rolls (kibblers) 3) then passed to the wet pan (revolving roller mill). This called ‘tempering’ the clay 4) then travels through one or more pairs of rolls (produce fine grinding) 5) then tempered clay delivered to a pug mill. Pug mill consolidates the clay and extrudes it in a column whose breadth and depth are calculated 6) if required, the column of clay can be sandfaced or textured before being cut by wires into bricks units 7) drying is carried out in the kilns

Last Updated:13 December 2017 © LMS SEGi education group 20 Semi-Dry Press Process It is a process in making of Fletton bricks: 1) fine clay dust delivered to machines where it is pressed to shape in moulds 2) the shaped bricks go direct to the kiln for wiring without intermediate drying Fletton bricks are one of softer brick and porous to a certain extent. This means they are not frost resistant and cannot be used as a finishing brick. This clay contains coal traces, which burn during firing, reducing the amount of fuel needed for the kiln, which not only keeps down costs but also produces some interesting effects in the bricks themselves.

Last Updated:13 December 2017 © LMS SEGi education group 21 Soft-Mud Also known as ‘stock’. The clay is wetted to a so-called "soft mud" and then moulded to shape, before being allowed to dry prior to firing in the kiln. Much of the process is automated. Tend to be slightly irregular in shape. Usually a bit more expensive than wirecuts.

Last Updated:13 December 2017 © LMS SEGi education group 22 Handmade Usually made on a bench, in a mould, much as described above for a stock brick. Because the clay isn't firmly compacted by machine, each brick normally has distinctive creasing known as a 'smile'. Very desirable, and the most expensive.

Last Updated:13 December 2017 © LMS SEGi education group 23 There are four types of kilns used for firing the bricks: 1. ______________ Centuries old firing method A clamp is formed by building up green bricks, stacked on a layers The fuel is ignited by small fires The clamp is usually then left to burn itself out & cooldown.

Last Updated:13 December 2017 © LMS SEGi education group 24 2.___________________ Kilns - used for the firing of special bricks - do not justify large-scale production - heated by fires at the outer walls - temperature gradually raised to cover each stage of the firing cycle 3. _________________ Kilns - consists of a number of chambers connected in such a way that fire can be led from one to another, so that the stationary bricks are heated, fired, and cooled. 4. _________________Kilns - more recent innovation - the bricks move, while the fire stay still - the brick will be carried on kiln car, pass along a tunnel through preheating, firing, & cooling zones.

Last Updated:13 December 2017 © LMS SEGi education group 25 8.0 Concrete Blocks Block for masonry construction may be made of several materials, but the most common is concrete. This is because concrete have high compressive strength and easy of handling individual block. Concrete block is available as either heavyweight or lightweight block depending on the type of aggregate used. Concrete blocks come in assorted sizes and shapes. Bricks and blocks differ in cuboidal shape, and blocks are generally __________________ than bricks

Last Updated:13 December 2017 © LMS SEGi education group 26 REFERENCES: http://www.pavingexpert.com/featur09.htm www.us-concrete.com/products/masonry.asp John, V.B. (1992) Introduction to Engineering Materials, 3rd edition, McMillan Press Ltd. Everett, A. (1996). Materials, 3rd edition Addison Wesley Longman Limited, England