Building Technology I - Div 04 Masonry PDF

BUILDING TECHNOLOGY I 1. MORTARS AND PLASTERS - a proportioned mixture of siliceous materials (sand, crushed stone) and cement (lime, Portland) which, after being prepared in a plastic state with water, hardens into a stonelike mass. Mortar is cement mix used to glue masonry units to each other, or...

BUILDING TECHNOLOGY I 1. MORTARS AND PLASTERS - a proportioned mixture of siliceous materials (sand, crushed stone) and cement (lime, Portland) which, after being prepared in a plastic state with water, hardens into a stonelike mass. Mortar is cement mix used to glue masonry units to each other, or other surface finishing materials like tiles, bricks, stones to a receiving structure like a wall or floor. Plaster is mortar applied to wall surfaces as a preparation or a hard finish coat. 1. MORTARS AND PLASTERS 1.01 CEMENT MORTAR - is a proportioned mixture of cement, fine aggregate and water. - For first-class mortars 1 part of cement should be added to not more than 3 parts of sand. - Replacing 10 or 15 percent of the cement by volume with hydrated lime gives greater workability and increases the strength of the mortar. - For rubble stonework, 1 : 4 will be much stronger than lime mortar. - For the top surface of floors and walks, use 1 : 1 to 1-1/2. - Mortar made with fine sand requires a much larger quantity of cement to obtain a given strength than mortar made with coarse sand. 1. MORTARS AND PLASTERS 1.01 CEMENT MORTAR - Mortar may be mixed by hand or mechanical mixers, the latter being preferred for large quantities. - When the mixing is done by hand, it should be done on platforms made watertight to prevent the loss of cement. - The cement and sand should be mixed dry in small batches in the proportions required on a clean platform. - Water is added and the whole remixed until it is homogeneous in color and leaves the mixing hoe clean when drawn out. - Mortar should never be retempered after it has begun to set 1. MORTARS AND PLASTERS 1.02 PLASTER - is a mortar of cementitious material ( lime, gypsum or cement), sand and water which is applied in coats (layers) to masonry surfaces, lath or various types of plaster board to give a hard finish surface to interior or exterior walls and ceilings. - the word “plaster” refers to gypsum plaster and the words gypsum and plaster are often used interchangeably. - Fiber or hair is sometimes added to the mixture to give increased strength as when used for the first coat. - Plastering is done according to two basic methods: two-coat and three-coat. A three-coat job consists of : a first binding coat called scratch coat; a second straightening coat called the brown-coat; and a final coat called the finish coat. In the two-coat work, the scratch and brown coats are combined into one. 1. MORTARS AND PLASTERS 1.03 TYPES OF PLASTER AND THEIR USES a. Lime Plaster Lime putty (hydrated lime and water), mixed on the job with sand and gypsum plaster, used for two and three-coat finish surfaces for interior walls and ceilings. Scratch coat : 1 part lime putty, 1 part Portland cement or Keene’s cement, 2-3/4 parts sand by weight. Brown coat : 1 part lime putty, 1part Portland cement or Keene’s cement, 3 parts sand by weight. Finish coat: Hard finish : 1 part lime putty, 1/3 gypsum plaster by volume Sand float : 1 part lime putty, ¼ gypsum plaster, 2 parts sand by volume 1. MORTARS AND PLASTERS 1.03 TYPES OF PLASTER AND THEIR USES b. Gypsum Plaster Gypsum plaster. Plaster of Paris mixed with clay, lime and other materials in combinations covered by trademarks or patents. Mixed on the job with water, sand, lime putty, hair or fiber for two or three-coat finish surfaces for interior walls and ceilings; or used dry as ingredient for hard or sand float finish with lime plaster (see above). High-strength gypsum plaster. Same as gypsum plaster but mixed to meet established standards. Mixed on the job with water, sand, lime putty, hair or fiber for two and three-coat finish surfaces for both exteriors and interiors. - Scratch and brown coats : - Hard finish : 1 part high-strength gypsum plaster to 2 parts sand by weight. ¼ lime putty to 1 part highstrength gypsum plaster by volume 1. MORTARS AND PLASTERS 1.03 TYPES OF PLASTER AND THEIR USES b. Gypsum Plaster Fibered gypsum plaster. Gypsum plaster premixed with fibers. Mixed on the job with water and sand for scratch coat for three-coat plastering job Prepared gypsum plaster. Gypsum plaster mixed with fine white sand. Used for two and three-coat finish surfaces for interior walls and ceilings. - Scratch and brown coats : mix per manufacturer’s instructions. - Finish coat: Any type of final coat plaster (gypsum, Keene’s cement, lime or prepared finish coat 1. MORTARS AND PLASTERS 1.03 TYPES OF PLASTER AND THEIR USES b. Gypsum Plaster Bonding plaster. Gypsum plaster mixed with ingredients develop more adhesive strength in combinations covered by trademarks or patents. Used for interior finish for smooth concrete walls or ceilings. Mix and apply as per manufacturer’s directions Lightweight gypsum plaster, fire-resistant plaster. Gypsum plaster mixed on the job with water, perlite, vermiculite or other suitable mineral aggregate. Lightweight gypsum plaster is used when weight is important, and for fire-proofing other materials such as steel. Applied on lath. For interior use only. - Scratch and brown coats : - Brown coat: - Finish coat: Hard finish: Sand Float Finish: 2 sand, 2 cu. ft. perlite or vermiculite per 100 lb. of plaster. 3 sand, 3 cu ft. perlite or vermiculite per 100 lb. of plaster. 1/3 gypsum plaster, 1 lime putty by volume 1 gypsum plaster, 1-1/2 sand by volume 1. MORTARS AND PLASTERS 1.03 TYPES OF PLASTER AND THEIR USES b. Gypsum Plaster Keene’s cement. Plaster of Paris mixed with alum or borax or other materials and burned (calcined) at 932F. Mixed on the job with water, lime putty and fine white sand as hard finish for two and three-coat gypsum plaster. For interior use only - Hard finish : - Sand float finish : 1 Keene’s cement, ¼ lime putty, 1/10 fine white sand by weight. ½ Keene’s cement, 2 lime putty, 4 ½ sand by volume. Plaster of Paris. For ornamental plaster work and castings. Molding plaster. For ornamental plaster work and castings. Mix with water as per manufacturer’s directions. Acoustics plaster. For acoustic treatment of interior walls and ceilings. Applied on gypsum plaster base coats. Mix with water as per manufacturer’s directions. 1. MORTARS AND PLASTERS 1.03 TYPES OF PLASTER AND THEIR USES c. Portland Cement Plaster Mixed with water, sand and lime putty. Used for two and threecoat finish surfaces for exterior and interior walls and ceilings - Scratch and brown coats : 1 cement, ¼ lime putty, 3 sand. - Sand float finish : 1 cement, ¼ lime putty, 3 sand. Thickness of plaster coats depends on the type of material to which the plaster is applied. Generally, the total thickness is 5/8” on metal lath and ½” on lathing board and gypsum block. In three-coat plastering work, the scratch and brown coats are ¼” thick at minimum; the finish coat is 1/8” with a minimum of 1/16” at any point. For two-coat work, the base coat is ½” and the finish coat is the same as three-coat work. 1. MORTARS AND PLASTERS 1.03 TYPES OF PLASTER AND THEIR USES d. “Sgraffito” is highly decorative type of plaster work developed in Italy during the Renaissance. This type of technique consists of applying two or three thin coats of plaster different colors and then cutting away certain areas of one or two coats to produce a three-dimensional colored design. 2. UNIT MASONRY 2.01 DEFINITION Masonry - is a built-up construction or combination of building materials as clay, concrete, or stone set in mortar; or plain concrete. Masonry Terms: a. Bed – The horizontal surfaces on which the stones or bricks of walls lie in the courses. b. Course – A continuous layer of bricks, stones, or other masonry units c. Wythe or Tier – Each continuous, vertical section of the wall, one masonry unit thick. Course Wythe or Tier 2. UNIT MASONRY 2.01 DEFINITION Masonry Terms: d. e. f. Bond – That connection between bricks, stones or other masonry units formed by lapping them one upon another carrying up the work, so as to form an inseparable mass of building, by preventing the vertical joints falling over each other (also called a breaking joint). Stretcher – A brick or block masonry laid lengthwise of a wall English Bond Stretcher Header – A brick or block masonry extending over the thickness of the wall Header 2. UNIT MASONRY 2.01 DEFINITION Masonry Terms: g. Heading course – A course in which the bricks or other masonry units are all headers. h. Soldier – A unit laid on its end with its face perpendicular to the face of the wall. i. Quoins – The corner stones at the angles of buildings, usually rusticated so as to project from the normal surface of the wall. j. Bond Stones – Stones running through the thickness of the wall at right angles to its face, in order to bind it together. k. Blocking or Blocking Course – A course of stones placed on top of cornice crowning the walls Soldier 2. UNIT MASONRY 2.02 STONE - Stone, together with wood and clay, are the basic building material of man. The history of architecture until as late as 1900 was largely the history of stone in architecture, - Stone was the structural material, the exterior and interior finishing material, the flooring material and in many cases the roofing material. - It was also used for all types of sculpture, statuary, and decorative and ornamental applications. - Today, stone is largely used as a surface finishing material for both the exterior and interior of buildings. 2. UNIT MASONRY 2.02 STONE - Stone commonly used for architectural purposes include granite limestone marble sandstone travertine slate. 2. UNIT MASONRY 2.02 STONE They are commonly classified as: a. Rubble Stone. Stone delivered from the quarries rough and irregular shape. b. Dimension Stone. Stone cut into specific size, squared to dimensions, and to a specific thickness 2. UNIT MASONRY 2.02 STONE - STONEWORK: The types of stonework are based on the shape and the surface treatment of finish of the stone : a. Rubble work. Masonry of rough, undressed stones. When only the roughest irregularities are knocked off, it is called scabbled rubble, and when the stones in each course are rudely dressed to a nearly uniform height, range rubble. b. RUBBLE WORK Random work. Stones fitted together at random without any attempt to lay them in course. RANDOM WORK 2. UNIT MASONRY 2.02 STONE - STONEWORK: c. Ashlar. Squared stones in regular courses, in contradistinction to rubble work. Ranged work or coursed ashlar – Uniform courses with stones uniform in size. BROKEN RANGED WORK Broken range ashlar – Course laid with the horizontal joints uninterrupted but the width of the courses and the length of the stones are varied to produce a wall with a less regular pattern. 2. UNIT MASONRY 2.02 STONE - STONEWORK: c. Ashlar Random course their rectangular shape and are laid on horizontal beds but no effort is made to continue the horizontal beds through in an uninterrupted manner. Large stones combine with small ones in a convenient and, if possible, an interesting manner. Rustic or Rock work Courses of stone face which is jagged, so as to present a rough surface. RANDOM COURSE WORK RUSTIC OR ROCK WORK * Rustication occurs when heavier stones or areas of stone project from the normal face of the surrounding wall or of the joint themselves. 2. UNIT MASONRY 2.03 BRICKS - are structural units of clay or shale formed while plastic and subsequently fired. - The manufacture of brick consists essentially of screening, grinding, or working the clay to the desired consistency for moulding, whether by hand or machine. - After moulding, the bricks are dried and then burned in kilns for many hours at high temperatures, approximately 2000F. - These processes purify the raw products, make it uniform and homogeneous, burn out all combustible matter, and result in a product which is both stable and physically permanent. - Standard size of brick is 3-3/4” x 2-1/4” x 8”. 2. UNIT MASONRY 2.03 BRICKS The types of bricks most frequently used in architecture are : a. Common or building brick. Used for all purposes, including facing. b. Facing brick. Specially processed to give certain specific surface characteristics. Used for exposed masonry surfaces. c. Glazed brick. These have a smooth outer surface with a dull satin or high gloss finish. They are load bearing, fire resisting, and impervious. They are usually formed with vertical hollow cores through the body with scoring on the back. d. Fire (refractory) brick. These are ordinarily made from a mixture of flint clay and plastic clay, and are used for the lining of furnaces, fireplaces, and chimneys. 2. UNIT MASONRY 2.03 BRICKS BRICK WORK. The usual methods of laying brick are as follows : a. Common Bond. Consists of five stretcher courses and then a header course. It is generally begun with a row of headers at the bottom course b. English Bond. Consists of alternate courses of stretchers and headers. c. Flemish Bond. Consists of alternate headers and stretchers in each course. d. Herringbone. The bricks are laid diagonally to form a herringbone pattern. COMMON BOND ENGLISH BOND FLEMISH BOND 2. UNIT MASONRY 2.03 BRICKS Mortar joints between brick courses are usually from 4.5mm (3/16”) to 12mm (½”). 2. UNIT MASONRY 2.04 CONCRETE HOLLOW BLOCK Concrete Hollow Block (CHB) is a hollow masonry unit, with two or three cells or cores, made of the following ingredients: water, Portland cement, and various types of aggregate such as sand, gravel, and crushed stone. Lightweight concrete hollow blocks are also manufactured with such aggregates as cinders, expanded slag, expanded shale or clay. Expanded blast furnace slag rates the highest in fire resistance, and due to its cellular structure, has high sound and thermal insulation quality. These are manufactured by machine-mixing the ingredients, pouring the mix into molds, and curing the block by air drying. A steam-and-pressure curing process is also used which can produce concrete hollow block in a few hours. 2. UNIT MASONRY 2.04 CONCRETE HOLLOW BLOCK Standard CHB sizes are from thicknesses of 100mm (4”), 150mm (6”) and 200mm (8”) x height of 200mm (8”) x length of 400mm (16”). CHB of 100mm (4”) thickness should be used only for interior partition walls where weather-tightness is not required. 2. UNIT MASONRY 2.04 CONCRETE HOLLOW BLOCK The different types of concrete hollow block include: a. Stretchers c. Corner blocks b. Headers d. Jamb blocks e. Beam or lintel blocks 2. UNIT MASONRY 2.04 CONCRETE HOLLOW BLOCK Concrete hollow blocks should be laid on a full bed of mortar with horizontal and vertical joints 10mm (3/8”) thick. Reinforcement for 100mm (4”) and 150mm (6”) thick wall shall be 10mm vertical bars at 600mm on centers and 10mm horizontal bars every third course. Reinforcement for 200mm (8”) thick walls shall be 12mm vertical bars at 600mm on center and 12mm horizontal bars every third course. All horizontal reinforcement shall be tied to the vertical reinforcement at their intersections. Dowel bars should be placed into the piers, columns, slabs, leaving 20 bar diameters exposed to splice with the reinforcement of the hollow blocks. 2. UNIT MASONRY 2.04 CONCRETE HOLLOW BLOCK Block cells with reinforcement are filled with cement mortar. Concrete hollow block walls should have a reinforced concrete lintel or beam block course every twelfth course; and a concrete column stiffener at every 4.80 meters length. 2. UNIT MASONRY 2.05 “DURISOL” BLOCK - “DURISOL” block is lightweight block made from fiber and cement. - “DURISOL” block units are two-core, 100mm (4”) or 150mm ( 6”) x 87mm (71/2”) x 600mm (24”). - Reinforcement shall be 10mm  vertical bars at 720mm (36”) on center and at every 4th course. Every 4th course should be a beam block course. Cores shall be solidly filled with cement mortar. 2. UNIT MASONRY 2.06 PLASTER BLOCK - also known as gypsum partition blocks, are usually made of gypsum, vegetable fibers as binders, and reinforcement. - used for lightweight, fire-resistant interior partitions and for furring and fireproofing columns. - Gypsum hollow blocks are manufactured in units of 75mm (3”), 100mm (4”) or 150mm ( 6”) thicknesses, x 300mm (12”) height x 700mm (30”) length. - Gypsum solid block is manufactured only with a 50mm (2”) thickness. 2. UNIT MASONRY 2.07 STRUCTURAL CLAY TILE - Structural clay tile are hollow masonry units, open at two ends with interior webs or partitions 19mm (¾”) to 25mm (1”) dividing the block into longitudinal cells. - In its manufacture, the various shapes of clay tile are formed through special dies and then wire-cut into the required lengths. - It may have a smooth or scored (grooved) surface. Structural clay tile is classified into: a. b. Load-bearing wall tile. 300mm x 300mm x 300mm (12” x 12” x 12”) Non-load bearing, fireproofing, partition, and furring tile. 100mm (4”) or 125mm (5”) x 200mm x 300mm End of Div 04 MASONRY