Brick Baru
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INTRODUCTION What is masonry? Masonry has been generally defined as an assembly of brick, stone, concrete masonry units, structural clay tile, architectural terra cotta, glass block, gypsum block, or similar material bonded together with mortar to form walls and others parts of buildings. Masonry is generally a highly durable form of construction. However, the materials used, the quality of the mortar and workmanship, and the pattern the units are put in can strongly affect the durability of the overall masonry construction. Masonry is commonly used for the walls of buildings, retaining walls and monuments. Brick is the most common type of masonry and may be either weightbearing or a veneer. Concrete block masonry is rapidly gaining in popularity as a comparable material. Blocks is defines most of which have hollow cores that is offer various possibilities in masonry construction. They generally provide great compressive strength, and are best suited to structures with light transverse loading when the cores remain unfilled. Filling some or all of the cores with concrete or concrete with steel reinforcement (typically "rebar") offers much greater tensile and lateral strength to structures. However, since modern-day technology is outpacing the redefinition of terms, it might be more practical, but, basically to discuss and review these materials it¶s dividing them into two basic categories which are unit masonry and stone. Unit masonry materials manufactured units of size that are generally handled and erected by one mason. However, there are exceptions to this simple definition in that prefabricated panels of brick and concrete masonry units require several masons to erect them. Unit masonry includes such materials as brick, concrete block and concrete brick. And then stone is primarily a natural quarried material that can be assembly with mortar. But, in our discussion only discuss and review about brick, concrete block, and stone masonry.
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BRICK Building bricks are solids masonry units compared of inorganic nonmetallic materials hardened or burned by heat or chemical action. Building brick may be solid or it may have cored openings not to exceed 25 percent of its volume. Brick are produced in a wide variety of colors, shapes and textures. Classes of bricks Bricks are generally classified as adobe, made of natural sun-dried clays or earth and a binder; kiln burned, composed of clays or shale¶s to which other materials may have been added and fired to hardness; sand-lime, mixtures of sand and lime hardened under steam pressure and heat; and concrete, solid or cored units composed of Portland cement and aggregates. Adobe brick: Sun-dried brick formed of sandy clay found in the Southwestern Unites States has been used for centuries by the various Indian tribes of the area. Adobe brick is still used in this semiarid area, where its good insulating qualities can be used to advantage. Modern adobe brick is composed of soils that contains sufficient clay to bind the particles together but does not contain more than 0.2 percent of water-soluble salts. The soil is mixed with a stabilizing agent of emulsified asphalt to provide the required resistance to absorption. Adobe bricks are commonly 3 in 6 in [76 to 152 mm] high, 8 in to 13 in [203 to 330 mm] wide, and from 12 in 18 in [305 to 457mm] long. Kiln-burned brick: This most widely used type of building brick is made of natural sand and clays or shale. These clays are composed of silicate or alumina and small percentages of other minerals. Clays with a large percentage of feldspar and iron oxide turn salmon, red, or brown on firing. Clays with a large percentage of calcium carbonate burn to a yellowish color. Shale is a type of clay that has been solidified under pressure. It is a type of clay that has been solidified under pressure. It is not soluble in water in its solid form and must be ground or pulverized to be used in the manufacturer of clay product. Sand-lime brick: Sand-lime brick is a pearl-grey brick formed much like dry-pressed burned-clay brick. Lime, in the form of dolomite lime or high calcium lime, is mixed with
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clean, washed sand and allowed to stand for several hours before it is delivered to a press. The brick is then allowed to harden in closed vessels under steam pressure. The grading and use of sand-lime brick are similar to those of hard-burned clay brick. Concrete brick: Concrete (cement brick) is made of Portland cement and a suitable aggregate. The materials are mixed together and formed in molds of the same size as burned brick. The brick may be cured by steam or by the dry process. Concrete brick is used where a particular texture or color is desired. Manufacture of brick The clay used for kiln-burned brick are usually obtained by surface digging or quarrying. Some clay requires some preparation, while others require extensive grinding. The clay is to delivered to a granulator, which breaks up the largest pieces with steel knives. It is then discharged onto large pans, where it is ground to a fine powder by steel rollers. After the clays is ground, it is tempered in a pug mill. Tempering is the process of reducing the clay to a homogenous plastic mass. At this point sand and water added to produce the desired consistency for molding. Bricks may be molded by a soft-mud, stiff-mud, or dry-process. The soft-mud process consists of mechanically forcing wet, soft clay into molds. The molding machine forces the wet clay into several molds under pressure, cuts off excess clay, and turns the molded bricks out onto a pallet or conveyor, to be carried away for drying. The inside of the mold may be sprayed or dipped in water to prevent clay from sticking. These bricks are called water-struck bricks. Sand-struck bricks generally have sharper, cleaner edges than water-struck bricks. In the stiff-mud process only enough water is used to form the clay into a cohesive mass, which is then to forced or extruded in a column through dies in a brickmaking machine. The column of clay is forced onto a wire cutting table, where it is cut into appropriate lengths by taut wires. This produces a wire-cut face. Brick may be end cut or side cut, depending on the size and shape of the die. Dry-pressed brick is manufactured of relatively dry or nonplastic clays. The material is fed into the machine by hoppers, where it is compressed into molds under
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high pressure. Dry-pressed brick are compact, strong, and well-formed. Many face bricks are formed by this process. When the bricks come from the brick-making machine, they contain from 7 to 30 moisture content, depending on the process used. They may be stacked in open sheds for periods of 7 days to 6 weeks for final drying. Most brick is now dried in mechanical driers under controlled conditions of heat, moisture, and air velocity for 2 to 4 days. Brick kilns The earliest type of kiln used to fire brick consisted of a series of arches composed of the natural dried brick. The remainders of the dried, or green, bricks were piled on top of the arches, and a fire was built under the arches. As the heat distribution in this type of kiln is very uneven, the bricks closest to the fire were burned to a vitrified shiny surface that was almost black. These shiny, occasionally warped, dark bricks are sometimes used for special architectural effects. The bricks at the top of the pile were partially burned and were a light-pink or salmon color. Those in between varied in color and hardness, depending on their location in the pile. While this type of kiln may still be used in some small brickyards, most brick are now burned in kilns having permanent enclosures, with the heat generated in ovens outside the wall. The heat may be furnished through grates under bricks piled in arches as before. These kiln are called up-draft kilns. If the heat enters near the top of the kiln and passes down through the piled brick and out through openings in the floor to chimneys, the kiln is called a downdraft kiln. Kilns may be either intermittent or continuous. In the intermittent kiln, the bricks must be fired, the fires extinguished, the brick allowed to cool, the kiln dismantled, and the bricks removed before a new pile of green bricks is piled to be fired. The development of the continuous kiln greatly speeded up the process. The continuous kiln may consist of several compartments fired by a single oven. The heat is regulated in each section so that while the remaining water is being removed from the brick in one compartment, bricks are being fired in a second compartment and cooled in a third. The continuous tunnel kiln is now widely used. The tunnel kiln consists of either a straight or a curved tunnel, with several zones in which heat is carefully controlled. Bricks are
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loaded onto special cars and pulled through the preheating, firing, and cooling zones at a constant rate of speed. The tunnel kiln is very efficient and produces a more uniform product. Brick types and size Bricks are available in many different sizes and types, which vary greatly from area to area. For example, over 100 different clay-brick unit are manufactured in southern California alone. Hence the designer of brick-masonry structure must check carefully to ascertain whether a particular type, color, or texture is manufactured or stocked locally. The most generally used solid clay masonry units are common building brick, face brick, special brick and custom brick (see Figure 4-5).
Figure 4-5
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Common brick: Common brick is the most widely used building brick. This is the ordinary red brick used for walls, backing, and other structures where a special color, shape, or texture is not required. The color may vary from dark orange to a deep red color, depending on the composition of the local clay. Common brick can obtained in some areas with rug-face, ruffle, scored, combed, roughened, smooth, wire-cut, barkface, stone-face, and several other finishes. Grades of common brick are shown in table 4-2. Common brick are manufactured in many sizes. While the masonry industry has been working for the many years to standardize brick sizes, a survey in 1976 showed that more than 50 different sizes of brick were being produced in southern California. The sizes produced in local areas must be checked carefully. The Masonry Institute of America has recommended that the sizes be standardized as shown in Tables 4-3, 4-4, and 4-5. (Metric brick sizes have not yet been established in the Unites States). Modular brick: Bricks which can be laid to modular dimensions are available in some localities. These brick are sized so that the brick plus the mortar joint will form a 4 in, or 12 in increment, or module. Thus three bricks 25/12 in × 33/4 in × 73/4 in plus 1/4 in joints would form a 4 in × 8 in × 8 in block. Face brick: Face brick is made under controlled conditions that produce close dimensional tolerances and high structural qualities. It is available in two grades, which conform to the same standards as SW and MW grades of common brick. The ASTM groups face brick into three basic appearance classifications, as shown in table 4-5. Standard sizes of face brick are shown in table 4-4. Glazed face brick: Glazed brick is produced to the same close tolerances as other face brick, but it has been given a hard, impervious face with a dull, satin, mottled, or glossy finish. The brick is sprayed with a ceramic glaze and is then fired to temperature of nearly 2000oF [1090oC] to fuse the glaze to the brick. Many colors, texture, and finishes are produced by applying metallic salts to the face of the brick before firing. This transparent salt-glaze allows the original brick color to show through the glaze.
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Fire brick: Brick made of clays having a high percentage of alumina or silica, flint, and feldspar are used where masonry will be subject to extreme heat. Fire brick is used for the lining of fireplaces, incinerators, chimney, stacks, industrial fire boxes, and smelting furnaces. Fire brick is softer than common brick and is light beige to brown in color. A fire brick is normally 21/2 × 41/2 × 9 in; fire-brick splits are 11/4 × 41/2 × 9 in. Cored brick: Some building codes allow the use of unreinforced 6-in [152-mm] walls. A type of brick with 10 vertical cores 13/8 in in diameter was developed in order to satisfy the need for a masonry unit 51/5 × 21/16 × 111/2 in, for use with 1/2, in joint. The vertical cores through the unit reduce the weight. The SCR, produced by Structural Clay Research, is a brick of this type. A wall constructed of SCR brick looks like a wall laid up with Norman brick. Paving brick: Special hard-burned paving bricks, or pavers, are produced for installation where wear or abrasion is a factor. These pavers are burned at a high temperature to make them impervious to water and resistant to abrasion. They are usually obtainable in depth of 21/3, 3, and 31/2 with a 4 × 81/2 in face. Special brick Brick is manufactured in special shapes for specific purposes. Caps, sills, lintels, and corners are manufactured and stocked by many producers. Bull-nose shape bricks are manufactured for window and door trim. Interior and exterior rounded corners are sometimes available. The increased use of reinforcement brickwork has led to the development of special shapes to allow either horizontal or vertical steel reinforcing to be placed in the brick wall. Many building brick codes in areas are subjected to wind or earthquake require reinforcement of masonry construction, and most companies now produce these special shapes in either standard or modular sizes. Brick made to order for special design are also available from many brickmakers. These custom bricks may be made in special shapes, colors, and textures. One architect wanted a special long, thin unit to carry out the lines of his building. The owner of a chain of motels and restaurants wanted a unique brick to be used in all his buildings to establish a company image. The cost of custom brick may often be offset by the importance of such factors.
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BRICKWORK Brickwork involves the assembly of masonry units including mortar, jointing, bond, tieing and workmanship to ensure performance, appearance, strength, and weather tightness. Other factor which influence heat transmission, sound transmission, and fire resistance are a function of the design of a masonry wall. Mortar The primary function of mortar is to bond masonry units together so that the mortar joint is durable and acts as a seal against the entrance of water. Other important properties of mortar are workability, water retentively, and strength. The primary ingredients of mortar are cementitious material, aggregate, and water. Two standards for mortar are available: ASTM C270 and Brick Institute of America (BIA) M1-72. Essentially, the BIA standard restricts the cementitious ingredients to Portland cement and lime, whereas the ASTM standard also allows the use of masonry cement as one of the cementitious ingredients. Canada Building Digest 163 states: ³it is difficult to predict the properties of masonry cement since their composition is not always published. Their use should therefore be based on the basic of known local performance.´ BIA standard M1-72 lists four types of mortar as shown on table 4-3-1. Portland cement ±lime mortars are proportioned by volume in accordance with information shown in table 4-4-1. As stated at the outset, the most important functions of mortar are its bonding or adhesive qualities and its durability. Bonding is increased by: 1. Mixing mortar to the maximum flow (ASTM C109) compatible with workmanship. This means using maximum amount of water and retempering. 2. Wetting clay units whose suction rate exceeds 20 grams per minute.
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Joints The aesthetics of brick joint are determined by its size, color, and the manner in which it is tooled. The method by which a joint is tooled also contributes to the watertightness of the wall. The tooled concave joint which compresses the mortar tightly against the masonry units produces the best resistance to water penetration by densifying the surface of the mortar. Joints should be made after the mortar has received its initial set; this compensates for any initial shrinkage. Joints that are made by cutting with a trowel or that are rubbed or designed so that they do not shed water run the risk of admitting water. Such joints where desired as part of the aesthetic purpose should be limited to designs using cavity wall construction. Joints sizes are a function of the masonry unit size and type. Glazed brick joints are generally ¼ inch; facing brick joints, 3/8 to ½ inch; and building brick joints ½ inch. Typical joints are shown in figure 4-3-1.
Figure 4-3-1
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Bond patterns While masonry bonding is the laying of units in rows or courses to tie the units together, bonds are also designed to enhance the appearance of a masonry wall. Depending upon the wall design (solid wall, cavity wall, or faced wall), either masonry bonding or metal ties are employed to bond the units into a solid mass. Each course of brick is one continuous horizontal layer bonded with mortar. The course can consist of brick laid end to end (stretcher) and/or with header (short dimension). In solid or cavity wall, each continuous vertical section of masonry one unit in thickness constitutes a wythe. The manner in which the wythes are bonded or tied creates a bond pattern. See figure 4-4-1 for bond patterns. 1. Stretcher or Running Bond: A pattern created by laying brick end to end (long dimension) with each course breaking joints at the midpoint of the course below. 2. Common Bond: a pattern consisting of stretcher or running bond courses, six or seven courses high with a course header (short dimension) laid perpendicular to the stretcher course and thus bonding into the inner wythe. 3. English Bond: A pattern consisting of alternating courses of stretchers and headers. 4. Flemish Bond: A pattern created by using one header followed by one stretcher in a course and with each course offset so that a header in one course is centered over the stretcher below. 5. Stack Bond: A pattern of brick stretchers laid so that horizontal and vertical joints are all in line. 6. Soldier course: Brick laid on end with the face showing; used essentially for belt courses or flat arches. 7. Rowlock Courses: Brick laid on face edge with end showing; used for sills or belt courses.
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Figure 4-4-1
Ties and Anchorage Masonry walls of the solid type are bonded together with either brick bond or metal ties. Cavity walls and faced walls (against concrete or brick veneer) are tied to the backing with various types of metal ties. Intersecting walls may be bonded with masonry or metal ties. Metal anchors and ties are usually of zinc-coated steel or other non-corrodible metal, and include a variety of types such as wire mesh, wire, corrugated metal, dovetails slots with flat dovetail anchors, rigid steel straps, cavity-wall anchors, and continuous horizontal reinforcement. See figure 4-5 for masonry wall ties. A study made by the Armour Research Foundation in 1960 concluded that continuous horizontal reinforcement is as effective as brick headers in tying walls against lateral wind loading. A similar study noted that solid walls bonded with metal ties had significantly greater resistance to water penetration than masonry bonded walls.
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Figure 4-5-1 Quality of Work Leaks in masonry walls are the result of the penetration of water through openings between mortar and brick rather than through mortar or brick. Therefore workmanship, rate of absorption of masonry units, and water retentively of mortar are the controlling factors affecting the construction of watertight masonry walls. To achieve this end result, do the following: 1. Lay brick in a full bed of mortar without furrowing. 2. Head of joints of stretcher courses should have end of each unit fully buttered with mortar. 3. Header courses should have each side fully buttered with mortar. 4. Shove each brick into place so that the mortar oozes out at the top of joints. In solid masonry construction, lay heavy back-up units first, parge its outer face, then lay face units. Tool face joints as here in before noted under joints.
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Since units with high rates of absorption will suck the water from the mortar, reduce the bond, and induce shrinkage cracks it may be necessary to wet the units prior to laying. Brick with high suction rates can be determined as follow: Draws a 1-inch diameter circle with a wax crayon on the bed of the unit. Place 20 drops of water inside the circle. If the water is absorbed in less than 11/2 minutes, the units should be wetted prior to laying, since their suction rate is high. Water retentivity of mortar is a measure of the flow and workability of a mortar. It is also the property of a mortar. It is also the property of a mortar which prevents ³bleeding´ or ³water gain´ when the mortar is in contact with retentivity, specify that the mortar have a flow after suction of not less than 75% of that immediately after mixing as determined by ASTM C91. Efflorescence The white soluble salt that sometimes appears as a deposit on masonry is known as efflorescence. This deposit is due to the entrance of water into the brickwork, the dissolving of salts (primarily sodium and potassium carbonates and sulfates), and their migration to the outer surface and deposition there in the form of a white soft powder. All of the ingredients used in masonry construction (brick, mortar, and water) may contain the salts described above. Face brick, ASTM C216 refers to test method ASTM C67 to preclude using brick that may cause efflorescence. Therefore, mortar ingredients and water may be the unknown source of these salts. The use of lime and Portland cement of low alkali content will greatly reduce the capacity of mortar to contribute to efflorescence. Water and sand can be checked by laboratory analysis for alkalinity to reduce the possibility of efflorescence.
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CONCRETE BLOCK Hollow masonry units of Portland cement, sand, gravel, or other suitable aggregate are termed concrete block. Concrete block is used for interior and exterior bearing and nonbearing walls, partitions, and backing. Precast concrete units to be set by masons are sometimes called artificial stone or cast stone. The weight, color, and texture of concrete block depend largely on the type of aggregate used in its manufacture. Block made with sand and gravel or crushed rock weights from 40 to 45 lb [18.1 to 20.4 kg] per 8 × 8 × 16 in [203 × 203 × 406 mm] unit. These blocks are strong and durable, with a low absorption rate. Blocks made with lightweight aggregate may weigh 25 to 35 lb [11.3 to 15.9 kg].Lightweight blocks are produced as non-load-bearing units, for use as backup walls, or as load-bearing-units, for use as the finished surface of both interior and exterior walls. Standard concrete blocks have the typical light gray color of concrete. Colored blocks may be made with naturally colored aggregates or by including inert mineral pigments in the concrete mix. Lightweight concrete blocks are available with colored surfaces produced by applying compounds of silica sand and color pigments. This type of block is used on interior where a smooth, durable, washable, colorful surfaces is desired. Lightweight concrete block is used where a lightweight material with good strength and high insulating or acoustical qualities is desired. Its use also simplifies the attachment of finish materials or accessories to a structural wall, in that common nails can be drive into the block.
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Types and Sizes Concrete block is manufactured in many sizes and shapes. The most commonly used block is designated as 8 × 8 × 16 in. It is designed to be laid up in a single thickness to produce a wall which is actually 75/8 in thick with courses 8 in high. For this reason the actual unit dimensions are usually 3/8 in smaller than the nominal sizes to allow for the thickness of mortar joints. For example, a standard 16 in unit is actually only 153/8 in long; with a 3/8 in mortar joint it will occupy 16 in in the wall. Similarly, the 75/8 in height plus a 3/8 in mortar joint is exactly 8 in. this allowance for mortar joints makes all wall measurements work out to even modular dimensions. Block are produced for the construction of walls and partitions in nominal thicknesses of 4 in, 6 in, 8 in, 10 in, and 12 in. half-blocks are produced for use at the ends of walls laid in running bond. Blocks 4 in high are available in some areas. The face shells and webs of concrete blocks vary in thickness from 11/4 to 2 in depending on the size of the block and the use for which it was designed. Some blocks are manufactured with closed cells at the ends, while others are open at one or both ends. Many special shapes are produced for specific purposes, Bullnose blocks , used for rounded exterior corners, are available in most sizes. Specially shaped sill blocks are manufactured for windows. Blocks with vertical slots cast in to one end are used in conjunction with the installation of metal windows or for the installation of wood bucks to which door casings can be nailed. Header and bond beam blocks are open-end blocks which have been hollowed out to allow the pouring of reinforced concrete beams over openings. Special shapes are produced for use where reinforced pilasters are to be included in a structural wall. Detailed block: Forms may be used in block-making machines to produce a block with a patterned face (see figs. 4-14, 4-15 and 4-16). Some block has vertical and horizontal grooves to simulate mortar joints. Block with triangular or rectangular indented areas may be laid in different directions to create interesting shadow patterns. Surface textures resembling that of rough adobe brick are produced in some areas. These textured blocks are called slumped block, termed Slump stone by one manufacturer.
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Screen units: The use of concrete masonry units to form open grilles is an innovation that has a great impact on building design, particularly in California. Screen-wall masonry units can be molded with an almost infinite variety of pierce openings (see fig. 4-17). The manufacturing of screen units is similar to that of standard concrete blocks. Sizes and shapes of unit vary with the patterns. The most common sizes are designed to make a screen wall that is 4 to 6 in [102 to 152 mm] thick when the units are set on edge. Screen units are set with mortar in the same manner as standard blocks. The horizontal and vertical joints may be reinforced to provide resistance to wind and earthquake forces. Standard concrete block may be used to develop a screen by exposing the cored openings. Screen-wall masonry units may be used as a veneer attached to a structural wall to create deep shadow lines and textures. If the units are used as a veneer, they are supported on an extension of the wall footing and tied to the structural wall with steel angles or tie wires.
Figure 4-14, 4-15, 4-16
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Figure 4-17
Reinforced Concrete Masonry Concrete masonry structures in areas subject to earthquake or severe windstorms must be reinforced in accordance with local building-code requirements. This is usually done by building reinforced concrete beams and studs as integral part of the concrete masonry wall. Vertical alignment of the hollow cores in the units permits reinforced-concrete studs or columns to be built at regular intervals in the wall, as well as at the corners, and the use of special block facilitates the construction of beams. Single-thickness structural concrete-block walls are usually erected on cast-inplace footings and foundations walls. Steel dowels are cast into the foundation walls at intervals corresponding to the open cells of the concrete blocks (see fig. 4-18). The spacing of these dowels and the length they must extend above the foundation are governed by local building codes. The reinforcing is located to coincide with the dowels extending up from the foundation. Horizontal steel reinforcing bars are placed at midheight, around openings, and as lintels or bond beams above openings. The masonry wall is usually built up to the first horizontal beam, and the vertical reinforcing steel is placed in the cells. At this point grout is poured in those cells that contain reinforcement to form a reinforced structural stud. To assure that the reinforcing is in place, and to clean out any mortar droppings, small openings or cleanouts are left at the bottom of all cells that are to be grouted.
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As the structural wall is built up, bolts, anchors, electrical conduit, pipes for plumbing, heating ducts, and other devices to be embedded in the wall must be placed on position. All bolts placed in a concrete-block wall must be adequately anchored by hooking around reinforcing steel or some other means to prevent the bolt from pulling out or failing under load. When a wood roof structures is to be connected, redwood plates are attached to the wall by means of bolts embedded in the bond beam at the top of the wall.
Figure 4-18
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STONE MASONRY Stone blocks used in masonry can be "dressed" or "rough." Stone masonry utilizing dressed stones is known as ashlar masonry, whereas masonry using irregularly shaped stones is known as rubble masonry. Both rubble and ashlar masonry can be laid in courses (rows of even height) through the careful selection and cutting of stones, but a great deal of stone masonry is uncoursed. Natural stone veneers over concrete masonry unit, cast-in-place, or tilt-up concrete walls are widely used to give the appearance of stone masonry. Sometimes "river rock" (oval shaped smooth stones) is used as a veneer. This type of material is not favored for solid masonry as it requires a great amount of mortar and can lack intrinsic structural strength. Manufactured-stone veneers are maturing in their popularity as an alternative to natural stones. Attractive natural stone has become more expensive in many areas and in some areas is practically unavailable. Manufactured-stone veneers are typically made from concrete. Natural stones from quarries around the world are sampled and recreated using moulds, aggregate, and colorfast pigments. To the casual observer there may be no visual difference between veneers of natural and manufactured stone. Otherwise, stone masonry walls are classified according to shape and surface finish of the stone as rubble, ashlar, and cut stone, or dimension stone. Within each of the classifications variations maybe used to provide interest or to bring out the characteristics of a particular type of stone (see fig. 4-31). Types of Stonework Rubble: Rubble masonry is composed of stones as they are either collected, called fieldstone, or as they come from the quarry. Thus the stones may have rounded natural faces or angular broken faces. Random rubble consists of fieldstones or quarry stones laid in an irregular pattern of sizes and shapes, with the large spaces between them filled with spalls, or broken bits of stone. A special type of rubble masonry, called polygonal, mosaic, or mosaic webwall, is composed of random-shaped stones fitted together to expose a web of more or less uniform mortar joints. Mosaic dry wall is similar, but is laid close together with no mortar showing. Coursed-rubble or strip-rubble
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walls are constructed of stone that has been quarried walls are constructed of stone that has been quarried in layers of uniform thickness or of roughly shaped stones laid in approximately level beds. The stones are split to length by the mason on the job. Ashlar: Ashlar masonry is constructed of squared stones set in random or uniform courses. Uniform continuous courses of the same height are called regular-course ashlar. Walls of squared stones if different sizes set in random courses are classed as random or broken-range ashlar. A wall of squared stones that is not measured and cut according to shop drawings, but is set at the discretion of the mason, is considered an ashlar wall. The surface finish of ashlar walls may be quarry face, hand split, or finish compatible to be stone used. Cut stone: Cut stone, sometimes called dimension stone, is define here as stones which are wholly fabricated and finished at the mill ready to be set in the building in conformity to drawings and specifications. Each stone is numbered and located on shop drawings and setting diagrams. Cut stones are seldom used as structural members. The most common use is as masonry veneer, which is attached to a backing with wire ties or nonrusting anchoring devices. The tie wires, corrugated metal straps, or anchoring devices. The tie wires, corrugated metal straps, or anchoring devices are cast into the mortar joint between the stones. Anchors for cut-stone veneer may be cast into structural-concrete backing walls. Dovetail slots may be formed into the structural wall to receive special anchors. These special anchors of brass, medium-hard drawn copper, or stainless steel fit into holes or slots drilled or sawed into the cut stone. The cut stone is held away from the backing by the anchors. Continuous horizontal angles bolted into the backing may be used to support and hold the-stone veneer in place. The spaces between the cut stones may be maintained by aluminum or plastic spacers (see fig. 4-32).
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Figure 4-31
Figure 4-32
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CONCLUSSION From deeply discussion and review of masonry which are concentrate to brick, concrete block, and masonry stone, we can concluded that have advantages and disadvantages in used these materials in construction especially in building. The advantages used of materials such as brick and stone can increase the thermal mass of a building, giving increased comfort in the heat of summer and the cold of winter and can be ideal for passive solar applications. Furthermore, brick typically will not require painting and so can provide a structure with reduced life-cycle costs, although sealing appropriately will reduce potential spalling due to frost damage different than concrete block which, the non-decorative variety generally is painted or stuccoed if exposed. It also can give the appearance, especially when well crafted, can impart an impression of solidity and permanence and is very heat resistant and thus will provide good fire protection. The disadvantages used of these materials can be seen when exposed to the extreme weather which, may cause degradation of the surface due to frost damage. This type of damage is common with certain types of brick, though relatively rare with concrete block. If non-concrete (clay-based) brick is to be used, care should be taken to select bricks suitable for the climate. In additional, masonry must be built upon a firm foundation usually reinforced concrete to avoid potential settling and cracking. If expansive soils such as adobe clay are present, this foundation may need to be quite elaborated and the services of a qualified structural engineer may be required. It is also effect at the high weight increases structural requirements, especially in earthquake prone areas. Lastly, the masonry consists of brick, concrete block, and masonry stone is very important as the materials for structural depends on its individual properties.
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APPENDIX
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REFERENCES
Don A Watson Construction Materials and Processes.1986
Harold J. Rosen, PE, FCSI Construction Materials for Architecture.1985 Arthur Lyons Materials for Architects and Builders 4th edition.2010 http://www.tpub.com/engbas/7-32.htm
http://www.flickriver.com/photos/14696209@N02/sets/72157621028957921/
http://en.wikipedia.org/wiki/Masonry
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BRICK Building bricks are solids masonry units compared of inorganic nonmetallic materials hardened or burned by heat or chemical action. Building brick may be solid or it may have cored openings not to exceed 25 percent of its volume. Brick are produced in a wide variety of colors, shapes and textures. Classes of bricks Bricks are generally classified as adobe, made of natural sun-dried clays or earth and a binder; kiln burned, composed of clays or shale¶s to which other materials may have been added and fired to hardness; sand-lime, mixtures of sand and lime hardened under steam pressure and heat; and concrete, solid or cored units composed of Portland cement and aggregates. Adobe brick: Sun-dried brick formed of sandy clay found in the Southwestern Unites States has been used for centuries by the various Indian tribes of the area. Adobe brick is still used in this semiarid area, where its good insulating qualities can be used to advantage. Modern adobe brick is composed of soils that contains sufficient clay to bind the particles together but does not contain more than 0.2 percent of water-soluble salts. The soil is mixed with a stabilizing agent of emulsified asphalt to provide the required resistance to absorption. Adobe bricks are commonly 3 in 6 in [76 to 152 mm] high, 8 in to 13 in [203 to 330 mm] wide, and from 12 in 18 in [305 to 457mm] long. Kiln-burned brick: This most widely used type of building brick is made of natural sand and clays or shale. These clays are composed of silicate or alumina and small percentages of other minerals. Clays with a large percentage of feldspar and iron oxide turn salmon, red, or brown on firing. Clays with a large percentage of calcium carbonate burn to a yellowish color. Shale is a type of clay that has been solidified under pressure. It is a type of clay that has been solidified under pressure. It is not soluble in water in its solid form and must be ground or pulverized to be used in the manufacturer of clay product. Sand-lime brick: Sand-lime brick is a pearl-grey brick formed much like dry-pressed burned-clay brick. Lime, in the form of dolomite lime or high calcium lime, is mixed with
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clean, washed sand and allowed to stand for several hours before it is delivered to a press. The brick is then allowed to harden in closed vessels under steam pressure. The grading and use of sand-lime brick are similar to those of hard-burned clay brick. Concrete brick: Concrete (cement brick) is made of Portland cement and a suitable aggregate. The materials are mixed together and formed in molds of the same size as burned brick. The brick may be cured by steam or by the dry process. Concrete brick is used where a particular texture or color is desired. Manufacture of brick The clay used for kiln-burned brick are usually obtained by surface digging or quarrying. Some clay requires some preparation, while others require extensive grinding. The clay is to delivered to a granulator, which breaks up the largest pieces with steel knives. It is then discharged onto large pans, where it is ground to a fine powder by steel rollers. After the clays is ground, it is tempered in a pug mill. Tempering is the process of reducing the clay to a homogenous plastic mass. At this point sand and water added to produce the desired consistency for molding. Bricks may be molded by a soft-mud, stiff-mud, or dry-process. The soft-mud process consists of mechanically forcing wet, soft clay into molds. The molding machine forces the wet clay into several molds under pressure, cuts off excess clay, and turns the molded bricks out onto a pallet or conveyor, to be carried away for drying. The inside of the mold may be sprayed or dipped in water to prevent clay from sticking. These bricks are called water-struck bricks. Sand-struck bricks generally have sharper, cleaner edges than water-struck bricks. In the stiff-mud process only enough water is used to form the clay into a cohesive mass, which is then to forced or extruded in a column through dies in a brickmaking machine. The column of clay is forced onto a wire cutting table, where it is cut into appropriate lengths by taut wires. This produces a wire-cut face. Brick may be end cut or side cut, depending on the size and shape of the die. Dry-pressed brick is manufactured of relatively dry or nonplastic clays. The material is fed into the machine by hoppers, where it is compressed into molds under
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high pressure. Dry-pressed brick are compact, strong, and well-formed. Many face bricks are formed by this process. When the bricks come from the brick-making machine, they contain from 7 to 30 moisture content, depending on the process used. They may be stacked in open sheds for periods of 7 days to 6 weeks for final drying. Most brick is now dried in mechanical driers under controlled conditions of heat, moisture, and air velocity for 2 to 4 days. Brick kilns The earliest type of kiln used to fire brick consisted of a series of arches composed of the natural dried brick. The remainders of the dried, or green, bricks were piled on top of the arches, and a fire was built under the arches. As the heat distribution in this type of kiln is very uneven, the bricks closest to the fire were burned to a vitrified shiny surface that was almost black. These shiny, occasionally warped, dark bricks are sometimes used for special architectural effects. The bricks at the top of the pile were partially burned and were a light-pink or salmon color. Those in between varied in color and hardness, depending on their location in the pile. While this type of kiln may still be used in some small brickyards, most brick are now burned in kilns having permanent enclosures, with the heat generated in ovens outside the wall. The heat may be furnished through grates under bricks piled in arches as before. These kiln are called up-draft kilns. If the heat enters near the top of the kiln and passes down through the piled brick and out through openings in the floor to chimneys, the kiln is called a downdraft kiln. Kilns may be either intermittent or continuous. In the intermittent kiln, the bricks must be fired, the fires extinguished, the brick allowed to cool, the kiln dismantled, and the bricks removed before a new pile of green bricks is piled to be fired. The development of the continuous kiln greatly speeded up the process. The continuous kiln may consist of several compartments fired by a single oven. The heat is regulated in each section so that while the remaining water is being removed from the brick in one compartment, bricks are being fired in a second compartment and cooled in a third. The continuous tunnel kiln is now widely used. The tunnel kiln consists of either a straight or a curved tunnel, with several zones in which heat is carefully controlled. Bricks are
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loaded onto special cars and pulled through the preheating, firing, and cooling zones at a constant rate of speed. The tunnel kiln is very efficient and produces a more uniform product. Brick types and size Bricks are available in many different sizes and types, which vary greatly from area to area. For example, over 100 different clay-brick unit are manufactured in southern California alone. Hence the designer of brick-masonry structure must check carefully to ascertain whether a particular type, color, or texture is manufactured or stocked locally. The most generally used solid clay masonry units are common building brick, face brick, special brick and custom brick (see Figure 4-5).
Figure 4-5
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Common brick: Common brick is the most widely used building brick. This is the ordinary red brick used for walls, backing, and other structures where a special color, shape, or texture is not required. The color may vary from dark orange to a deep red color, depending on the composition of the local clay. Common brick can obtained in some areas with rug-face, ruffle, scored, combed, roughened, smooth, wire-cut, barkface, stone-face, and several other finishes. Grades of common brick are shown in table 4-2. Common brick are manufactured in many sizes. While the masonry industry has been working for the many years to standardize brick sizes, a survey in 1976 showed that more than 50 different sizes of brick were being produced in southern California. The sizes produced in local areas must be checked carefully. The Masonry Institute of America has recommended that the sizes be standardized as shown in Tables 4-3, 4-4, and 4-5. (Metric brick sizes have not yet been established in the Unites States). Modular brick: Bricks which can be laid to modular dimensions are available in some localities. These brick are sized so that the brick plus the mortar joint will form a 4 in, or 12 in increment, or module. Thus three bricks 25/12 in × 33/4 in × 73/4 in plus 1/4 in joints would form a 4 in × 8 in × 8 in block. Face brick: Face brick is made under controlled conditions that produce close dimensional tolerances and high structural qualities. It is available in two grades, which conform to the same standards as SW and MW grades of common brick. The ASTM groups face brick into three basic appearance classifications, as shown in table 4-5. Standard sizes of face brick are shown in table 4-4. Glazed face brick: Glazed brick is produced to the same close tolerances as other face brick, but it has been given a hard, impervious face with a dull, satin, mottled, or glossy finish. The brick is sprayed with a ceramic glaze and is then fired to temperature of nearly 2000oF [1090oC] to fuse the glaze to the brick. Many colors, texture, and finishes are produced by applying metallic salts to the face of the brick before firing. This transparent salt-glaze allows the original brick color to show through the glaze.
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Fire brick: Brick made of clays having a high percentage of alumina or silica, flint, and feldspar are used where masonry will be subject to extreme heat. Fire brick is used for the lining of fireplaces, incinerators, chimney, stacks, industrial fire boxes, and smelting furnaces. Fire brick is softer than common brick and is light beige to brown in color. A fire brick is normally 21/2 × 41/2 × 9 in; fire-brick splits are 11/4 × 41/2 × 9 in. Cored brick: Some building codes allow the use of unreinforced 6-in [152-mm] walls. A type of brick with 10 vertical cores 13/8 in in diameter was developed in order to satisfy the need for a masonry unit 51/5 × 21/16 × 111/2 in, for use with 1/2, in joint. The vertical cores through the unit reduce the weight. The SCR, produced by Structural Clay Research, is a brick of this type. A wall constructed of SCR brick looks like a wall laid up with Norman brick. Paving brick: Special hard-burned paving bricks, or pavers, are produced for installation where wear or abrasion is a factor. These pavers are burned at a high temperature to make them impervious to water and resistant to abrasion. They are usually obtainable in depth of 21/3, 3, and 31/2 with a 4 × 81/2 in face. Special brick Brick is manufactured in special shapes for specific purposes. Caps, sills, lintels, and corners are manufactured and stocked by many producers. Bull-nose shape bricks are manufactured for window and door trim. Interior and exterior rounded corners are sometimes available. The increased use of reinforcement brickwork has led to the development of special shapes to allow either horizontal or vertical steel reinforcing to be placed in the brick wall. Many building brick codes in areas are subjected to wind or earthquake require reinforcement of masonry construction, and most companies now produce these special shapes in either standard or modular sizes. Brick made to order for special design are also available from many brickmakers. These custom bricks may be made in special shapes, colors, and textures. One architect wanted a special long, thin unit to carry out the lines of his building. The owner of a chain of motels and restaurants wanted a unique brick to be used in all his buildings to establish a company image. The cost of custom brick may often be offset by the importance of such factors.
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BRICKWORK Brickwork involves the assembly of masonry units including mortar, jointing, bond, tieing and workmanship to ensure performance, appearance, strength, and weather tightness. Other factor which influence heat transmission, sound transmission, and fire resistance are a function of the design of a masonry wall. Mortar The primary function of mortar is to bond masonry units together so that the mortar joint is durable and acts as a seal against the entrance of water. Other important properties of mortar are workability, water retentively, and strength. The primary ingredients of mortar are cementitious material, aggregate, and water. Two standards for mortar are available: ASTM C270 and Brick Institute of America (BIA) M1-72. Essentially, the BIA standard restricts the cementitious ingredients to Portland cement and lime, whereas the ASTM standard also allows the use of masonry cement as one of the cementitious ingredients. Canada Building Digest 163 states: ³it is difficult to predict the properties of masonry cement since their composition is not always published. Their use should therefore be based on the basic of known local performance.´ BIA standard M1-72 lists four types of mortar as shown on table 4-3-1. Portland cement ±lime mortars are proportioned by volume in accordance with information shown in table 4-4-1. As stated at the outset, the most important functions of mortar are its bonding or adhesive qualities and its durability. Bonding is increased by: 1. Mixing mortar to the maximum flow (ASTM C109) compatible with workmanship. This means using maximum amount of water and retempering. 2. Wetting clay units whose suction rate exceeds 20 grams per minute.
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Joints The aesthetics of brick joint are determined by its size, color, and the manner in which it is tooled. The method by which a joint is tooled also contributes to the watertightness of the wall. The tooled concave joint which compresses the mortar tightly against the masonry units produces the best resistance to water penetration by densifying the surface of the mortar. Joints should be made after the mortar has received its initial set; this compensates for any initial shrinkage. Joints that are made by cutting with a trowel or that are rubbed or designed so that they do not shed water run the risk of admitting water. Such joints where desired as part of the aesthetic purpose should be limited to designs using cavity wall construction. Joints sizes are a function of the masonry unit size and type. Glazed brick joints are generally ¼ inch; facing brick joints, 3/8 to ½ inch; and building brick joints ½ inch. Typical joints are shown in figure 4-3-1.
Figure 4-3-1
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Bond patterns While masonry bonding is the laying of units in rows or courses to tie the units together, bonds are also designed to enhance the appearance of a masonry wall. Depending upon the wall design (solid wall, cavity wall, or faced wall), either masonry bonding or metal ties are employed to bond the units into a solid mass. Each course of brick is one continuous horizontal layer bonded with mortar. The course can consist of brick laid end to end (stretcher) and/or with header (short dimension). In solid or cavity wall, each continuous vertical section of masonry one unit in thickness constitutes a wythe. The manner in which the wythes are bonded or tied creates a bond pattern. See figure 4-4-1 for bond patterns. 1. Stretcher or Running Bond: A pattern created by laying brick end to end (long dimension) with each course breaking joints at the midpoint of the course below. 2. Common Bond: a pattern consisting of stretcher or running bond courses, six or seven courses high with a course header (short dimension) laid perpendicular to the stretcher course and thus bonding into the inner wythe. 3. English Bond: A pattern consisting of alternating courses of stretchers and headers. 4. Flemish Bond: A pattern created by using one header followed by one stretcher in a course and with each course offset so that a header in one course is centered over the stretcher below. 5. Stack Bond: A pattern of brick stretchers laid so that horizontal and vertical joints are all in line. 6. Soldier course: Brick laid on end with the face showing; used essentially for belt courses or flat arches. 7. Rowlock Courses: Brick laid on face edge with end showing; used for sills or belt courses.
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Figure 4-4-1
Ties and Anchorage Masonry walls of the solid type are bonded together with either brick bond or metal ties. Cavity walls and faced walls (against concrete or brick veneer) are tied to the backing with various types of metal ties. Intersecting walls may be bonded with masonry or metal ties. Metal anchors and ties are usually of zinc-coated steel or other non-corrodible metal, and include a variety of types such as wire mesh, wire, corrugated metal, dovetails slots with flat dovetail anchors, rigid steel straps, cavity-wall anchors, and continuous horizontal reinforcement. See figure 4-5 for masonry wall ties. A study made by the Armour Research Foundation in 1960 concluded that continuous horizontal reinforcement is as effective as brick headers in tying walls against lateral wind loading. A similar study noted that solid walls bonded with metal ties had significantly greater resistance to water penetration than masonry bonded walls.
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Figure 4-5-1 Quality of Work Leaks in masonry walls are the result of the penetration of water through openings between mortar and brick rather than through mortar or brick. Therefore workmanship, rate of absorption of masonry units, and water retentively of mortar are the controlling factors affecting the construction of watertight masonry walls. To achieve this end result, do the following: 1. Lay brick in a full bed of mortar without furrowing. 2. Head of joints of stretcher courses should have end of each unit fully buttered with mortar. 3. Header courses should have each side fully buttered with mortar. 4. Shove each brick into place so that the mortar oozes out at the top of joints. In solid masonry construction, lay heavy back-up units first, parge its outer face, then lay face units. Tool face joints as here in before noted under joints.
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Since units with high rates of absorption will suck the water from the mortar, reduce the bond, and induce shrinkage cracks it may be necessary to wet the units prior to laying. Brick with high suction rates can be determined as follow: Draws a 1-inch diameter circle with a wax crayon on the bed of the unit. Place 20 drops of water inside the circle. If the water is absorbed in less than 11/2 minutes, the units should be wetted prior to laying, since their suction rate is high. Water retentivity of mortar is a measure of the flow and workability of a mortar. It is also the property of a mortar. It is also the property of a mortar which prevents ³bleeding´ or ³water gain´ when the mortar is in contact with retentivity, specify that the mortar have a flow after suction of not less than 75% of that immediately after mixing as determined by ASTM C91. Efflorescence The white soluble salt that sometimes appears as a deposit on masonry is known as efflorescence. This deposit is due to the entrance of water into the brickwork, the dissolving of salts (primarily sodium and potassium carbonates and sulfates), and their migration to the outer surface and deposition there in the form of a white soft powder. All of the ingredients used in masonry construction (brick, mortar, and water) may contain the salts described above. Face brick, ASTM C216 refers to test method ASTM C67 to preclude using brick that may cause efflorescence. Therefore, mortar ingredients and water may be the unknown source of these salts. The use of lime and Portland cement of low alkali content will greatly reduce the capacity of mortar to contribute to efflorescence. Water and sand can be checked by laboratory analysis for alkalinity to reduce the possibility of efflorescence.
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CONCRETE BLOCK Hollow masonry units of Portland cement, sand, gravel, or other suitable aggregate are termed concrete block. Concrete block is used for interior and exterior bearing and nonbearing walls, partitions, and backing. Precast concrete units to be set by masons are sometimes called artificial stone or cast stone. The weight, color, and texture of concrete block depend largely on the type of aggregate used in its manufacture. Block made with sand and gravel or crushed rock weights from 40 to 45 lb [18.1 to 20.4 kg] per 8 × 8 × 16 in [203 × 203 × 406 mm] unit. These blocks are strong and durable, with a low absorption rate. Blocks made with lightweight aggregate may weigh 25 to 35 lb [11.3 to 15.9 kg].Lightweight blocks are produced as non-load-bearing units, for use as backup walls, or as load-bearing-units, for use as the finished surface of both interior and exterior walls. Standard concrete blocks have the typical light gray color of concrete. Colored blocks may be made with naturally colored aggregates or by including inert mineral pigments in the concrete mix. Lightweight concrete blocks are available with colored surfaces produced by applying compounds of silica sand and color pigments. This type of block is used on interior where a smooth, durable, washable, colorful surfaces is desired. Lightweight concrete block is used where a lightweight material with good strength and high insulating or acoustical qualities is desired. Its use also simplifies the attachment of finish materials or accessories to a structural wall, in that common nails can be drive into the block.
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Types and Sizes Concrete block is manufactured in many sizes and shapes. The most commonly used block is designated as 8 × 8 × 16 in. It is designed to be laid up in a single thickness to produce a wall which is actually 75/8 in thick with courses 8 in high. For this reason the actual unit dimensions are usually 3/8 in smaller than the nominal sizes to allow for the thickness of mortar joints. For example, a standard 16 in unit is actually only 153/8 in long; with a 3/8 in mortar joint it will occupy 16 in in the wall. Similarly, the 75/8 in height plus a 3/8 in mortar joint is exactly 8 in. this allowance for mortar joints makes all wall measurements work out to even modular dimensions. Block are produced for the construction of walls and partitions in nominal thicknesses of 4 in, 6 in, 8 in, 10 in, and 12 in. half-blocks are produced for use at the ends of walls laid in running bond. Blocks 4 in high are available in some areas. The face shells and webs of concrete blocks vary in thickness from 11/4 to 2 in depending on the size of the block and the use for which it was designed. Some blocks are manufactured with closed cells at the ends, while others are open at one or both ends. Many special shapes are produced for specific purposes, Bullnose blocks , used for rounded exterior corners, are available in most sizes. Specially shaped sill blocks are manufactured for windows. Blocks with vertical slots cast in to one end are used in conjunction with the installation of metal windows or for the installation of wood bucks to which door casings can be nailed. Header and bond beam blocks are open-end blocks which have been hollowed out to allow the pouring of reinforced concrete beams over openings. Special shapes are produced for use where reinforced pilasters are to be included in a structural wall. Detailed block: Forms may be used in block-making machines to produce a block with a patterned face (see figs. 4-14, 4-15 and 4-16). Some block has vertical and horizontal grooves to simulate mortar joints. Block with triangular or rectangular indented areas may be laid in different directions to create interesting shadow patterns. Surface textures resembling that of rough adobe brick are produced in some areas. These textured blocks are called slumped block, termed Slump stone by one manufacturer.
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Screen units: The use of concrete masonry units to form open grilles is an innovation that has a great impact on building design, particularly in California. Screen-wall masonry units can be molded with an almost infinite variety of pierce openings (see fig. 4-17). The manufacturing of screen units is similar to that of standard concrete blocks. Sizes and shapes of unit vary with the patterns. The most common sizes are designed to make a screen wall that is 4 to 6 in [102 to 152 mm] thick when the units are set on edge. Screen units are set with mortar in the same manner as standard blocks. The horizontal and vertical joints may be reinforced to provide resistance to wind and earthquake forces. Standard concrete block may be used to develop a screen by exposing the cored openings. Screen-wall masonry units may be used as a veneer attached to a structural wall to create deep shadow lines and textures. If the units are used as a veneer, they are supported on an extension of the wall footing and tied to the structural wall with steel angles or tie wires.
Figure 4-14, 4-15, 4-16
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Figure 4-17
Reinforced Concrete Masonry Concrete masonry structures in areas subject to earthquake or severe windstorms must be reinforced in accordance with local building-code requirements. This is usually done by building reinforced concrete beams and studs as integral part of the concrete masonry wall. Vertical alignment of the hollow cores in the units permits reinforced-concrete studs or columns to be built at regular intervals in the wall, as well as at the corners, and the use of special block facilitates the construction of beams. Single-thickness structural concrete-block walls are usually erected on cast-inplace footings and foundations walls. Steel dowels are cast into the foundation walls at intervals corresponding to the open cells of the concrete blocks (see fig. 4-18). The spacing of these dowels and the length they must extend above the foundation are governed by local building codes. The reinforcing is located to coincide with the dowels extending up from the foundation. Horizontal steel reinforcing bars are placed at midheight, around openings, and as lintels or bond beams above openings. The masonry wall is usually built up to the first horizontal beam, and the vertical reinforcing steel is placed in the cells. At this point grout is poured in those cells that contain reinforcement to form a reinforced structural stud. To assure that the reinforcing is in place, and to clean out any mortar droppings, small openings or cleanouts are left at the bottom of all cells that are to be grouted.
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As the structural wall is built up, bolts, anchors, electrical conduit, pipes for plumbing, heating ducts, and other devices to be embedded in the wall must be placed on position. All bolts placed in a concrete-block wall must be adequately anchored by hooking around reinforcing steel or some other means to prevent the bolt from pulling out or failing under load. When a wood roof structures is to be connected, redwood plates are attached to the wall by means of bolts embedded in the bond beam at the top of the wall.
Figure 4-18
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STONE MASONRY Stone blocks used in masonry can be "dressed" or "rough." Stone masonry utilizing dressed stones is known as ashlar masonry, whereas masonry using irregularly shaped stones is known as rubble masonry. Both rubble and ashlar masonry can be laid in courses (rows of even height) through the careful selection and cutting of stones, but a great deal of stone masonry is uncoursed. Natural stone veneers over concrete masonry unit, cast-in-place, or tilt-up concrete walls are widely used to give the appearance of stone masonry. Sometimes "river rock" (oval shaped smooth stones) is used as a veneer. This type of material is not favored for solid masonry as it requires a great amount of mortar and can lack intrinsic structural strength. Manufactured-stone veneers are maturing in their popularity as an alternative to natural stones. Attractive natural stone has become more expensive in many areas and in some areas is practically unavailable. Manufactured-stone veneers are typically made from concrete. Natural stones from quarries around the world are sampled and recreated using moulds, aggregate, and colorfast pigments. To the casual observer there may be no visual difference between veneers of natural and manufactured stone. Otherwise, stone masonry walls are classified according to shape and surface finish of the stone as rubble, ashlar, and cut stone, or dimension stone. Within each of the classifications variations maybe used to provide interest or to bring out the characteristics of a particular type of stone (see fig. 4-31). Types of Stonework Rubble: Rubble masonry is composed of stones as they are either collected, called fieldstone, or as they come from the quarry. Thus the stones may have rounded natural faces or angular broken faces. Random rubble consists of fieldstones or quarry stones laid in an irregular pattern of sizes and shapes, with the large spaces between them filled with spalls, or broken bits of stone. A special type of rubble masonry, called polygonal, mosaic, or mosaic webwall, is composed of random-shaped stones fitted together to expose a web of more or less uniform mortar joints. Mosaic dry wall is similar, but is laid close together with no mortar showing. Coursed-rubble or strip-rubble
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walls are constructed of stone that has been quarried walls are constructed of stone that has been quarried in layers of uniform thickness or of roughly shaped stones laid in approximately level beds. The stones are split to length by the mason on the job. Ashlar: Ashlar masonry is constructed of squared stones set in random or uniform courses. Uniform continuous courses of the same height are called regular-course ashlar. Walls of squared stones if different sizes set in random courses are classed as random or broken-range ashlar. A wall of squared stones that is not measured and cut according to shop drawings, but is set at the discretion of the mason, is considered an ashlar wall. The surface finish of ashlar walls may be quarry face, hand split, or finish compatible to be stone used. Cut stone: Cut stone, sometimes called dimension stone, is define here as stones which are wholly fabricated and finished at the mill ready to be set in the building in conformity to drawings and specifications. Each stone is numbered and located on shop drawings and setting diagrams. Cut stones are seldom used as structural members. The most common use is as masonry veneer, which is attached to a backing with wire ties or nonrusting anchoring devices. The tie wires, corrugated metal straps, or anchoring devices. The tie wires, corrugated metal straps, or anchoring devices are cast into the mortar joint between the stones. Anchors for cut-stone veneer may be cast into structural-concrete backing walls. Dovetail slots may be formed into the structural wall to receive special anchors. These special anchors of brass, medium-hard drawn copper, or stainless steel fit into holes or slots drilled or sawed into the cut stone. The cut stone is held away from the backing by the anchors. Continuous horizontal angles bolted into the backing may be used to support and hold the-stone veneer in place. The spaces between the cut stones may be maintained by aluminum or plastic spacers (see fig. 4-32).
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Figure 4-31
Figure 4-32
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CONCLUSSION From deeply discussion and review of masonry which are concentrate to brick, concrete block, and masonry stone, we can concluded that have advantages and disadvantages in used these materials in construction especially in building. The advantages used of materials such as brick and stone can increase the thermal mass of a building, giving increased comfort in the heat of summer and the cold of winter and can be ideal for passive solar applications. Furthermore, brick typically will not require painting and so can provide a structure with reduced life-cycle costs, although sealing appropriately will reduce potential spalling due to frost damage different than concrete block which, the non-decorative variety generally is painted or stuccoed if exposed. It also can give the appearance, especially when well crafted, can impart an impression of solidity and permanence and is very heat resistant and thus will provide good fire protection. The disadvantages used of these materials can be seen when exposed to the extreme weather which, may cause degradation of the surface due to frost damage. This type of damage is common with certain types of brick, though relatively rare with concrete block. If non-concrete (clay-based) brick is to be used, care should be taken to select bricks suitable for the climate. In additional, masonry must be built upon a firm foundation usually reinforced concrete to avoid potential settling and cracking. If expansive soils such as adobe clay are present, this foundation may need to be quite elaborated and the services of a qualified structural engineer may be required. It is also effect at the high weight increases structural requirements, especially in earthquake prone areas. Lastly, the masonry consists of brick, concrete block, and masonry stone is very important as the materials for structural depends on its individual properties.
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APPENDIX
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REFERENCES
Don A Watson Construction Materials and Processes.1986
Harold J. Rosen, PE, FCSI Construction Materials for Architecture.1985 Arthur Lyons Materials for Architects and Builders 4th edition.2010 http://www.tpub.com/engbas/7-32.htm
http://www.flickriver.com/photos/14696209@N02/sets/72157621028957921/
http://en.wikipedia.org/wiki/Masonry
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