5.1 Design for Durability 56 - Guidelines for Laying Designa Basalt bricks 26 -General -Armaclay Building Guidelines 27 (Available in WA ONLY) - Masonry Units 57 - Mortar 60 -Verticore Building Standards 28 (Available in WA ONLY) - Ties, Connectors and Lintels 2.7 Brick Storage 29 - Reinforcement 5.2 Robustness of Brickwork 61 3. CLEANING & MAINTENANCE - Design Principles 3.1 Brick Cleaning and Maintenance 31 - Limiting Dimensions for Robustness 62 - Preventative Care is the First Step 5.3 Design to Avoid Cracking 65 - Cleaning Your Brickwork - General -Removing Common Stains - Locations of Articulation Joints 3.2 Cleaning Mortar stains with Hydrochloric Acid 33 - Detailing of Articulation Joints 67 -Control Joints 3.3 Hand vs High Pressure 34 5.4 Design Considerations of Designa Basalt 68 3.4 Efflorescence 35 5.5 Armabeam Clay Brick Lintels 76 3.5 Calcium staining/Scum 36 (Insoluble white deposits) (Available in WA only) 3.6 Iron Stains 37 5.6 Brick Estimator 77 3.7 Vanadium Stains 38 5.7 Brick Coursing Heights 78 3.8 Bowral Chillingham White Cleaning Instructions 39 5.8 Brick Gauge 79 3.9 Bowral Bricks Cleaning Instructions 40 - 230mm bricks 79 3.10 San Selmol Bricks Cleaning Instructions 41 - 290mm bricks 80 - 470mm bricks 81 - Armaclay/Verticore Brick 82 - Face Block 83 - Peninsula brick 84 Cover Image: La Paloma Miro. Architect: DKO Architecture. Photography: Peter Clarke

specified concrete compressive strength, psi d
effective depth of wall, but not to be taken larger than 80% of the wall length h
wall thickness Shear carried by the concrete should not exceed the smaller of the values of Vc computed from Eq. (9.112) or (9.113). N d V
3.3

hd  u (9.112) c c 4Lw where Nu
factored vertical axial load on wall acting with Vu, including tension due to shrinkage and creep (positive for compression, negative for tension). L (1.25

 0.2N /L h) w c uw V
0.6

  hd (9.113) c c M /V  L /2 u u w where Mu
factored moment at section where Vu acts. Alternatively, Vc
may be used if Nu 2

hd causes compression. Shear c strength Vc computed for a section at a height above the base equal to Lw/2 or onehalf the wall height, whichever is smaller, may be used for all lower sections. When Vu  0.5Vc, the area of horizontal shear reinforcement within a distance s2 required for shear is given by (V /  V )s A
u s 2 0.0025hs (9.114) h d 2 y where s2
spacing of horizontal reinforcement (max  Lw/5  3h  18 in) and y
yield strength of the reinforcement. Also, when Vu  0.5Vc, the area of vertical shear reinforcement with spacing s should be at least FIGURE 9.57 Components of a fixed arch. L A A
0.0025  0.5 2.5  h  h  0.0025 hs 0.0025hs (9.115) vh L nL w h where Lh is the wall height. But Avh need not be larger than Ah computed from Eq. (9.114). Spacing s should not exceed Lw/3, 3h, or 18 in. Arches are used in roofs for such buildings as hangars, auditoriums, gymnasiums, and rinks, where long spans are desired. An arch is essentially a curved beam with the loads, applied downward in its plane, tending to decrease the curvature. Arches are frequently used as the supports for thin shells that follow the curvature of the arches. Such arches are treated in analysis as two-dimensional, whereas the thin shells behave as three-dimensional elements. The great advantage of an arch in reinforced concrete construction is that, if the arch is appropriately shaped, the whole cross section can be utilized in compression under the maximum (full) load. In an ordinary reinforced concrete beam, the portion below the neutral axis is assumed to be cracked and does not contribute to the bending strength. A beam can be curved, however, to make its axis follow the lines of thrust very closely for all loading conditions, thus virtually eliminating bending

Virtually any species of wood can be used in the laminating process if the design values have been determined. Different species can be intermixed within the depth of a section to achieve optimum resource utilization. Higher-strength species are positioned in a beam in zones that will be subjected to high stresses under design loads. Lower-strength species can be placed in zones with lower in-service stresses. Similarly, manufacturer of glulam beams can be based on a graded layup concept. This requires that laminations with a higher lumber grading be used in zones subjected to high design stresses, and lower grades, in lower-stressed areas of the member. As a consequence, glulam members are a resource-efficient wood product, since varying grades and species can be used to achieve desired performance. Constant-depth members normally are a multiple of the thickness of the lamination stock used. Variable-depth members, because of tapering or special assembly techniques, may not be exact multiples of these lamination thicknesses. Nominal width of stock, in 4 6 8 10 12 Standard member finished width, in 3 or 31/8 5 or 51/8 63/4 81/2 or 83/4 101/2 or 103/4 Standard widths as listed above are most economical, since they represent the maximum width of board normally obtained from the stock used in laminating. Other widths, such as 31/2 or 51/2 in, which fit well with conventional 2  4 and 2  6 framing, are also available in many market areas. FIGURE 10.28 Finger joints: (a) fingers formed by cuts perpendicular to the wide faces of the boards; (b) fingers formed by cuts perpendicular to the edges. When members wider than the stock available are required, laminations may consist of two boards side by side. These edge joints must be staggered, vertically in horizontally laminated beams (load acting normal to wide faces of laminations), and horizontally in vertically laminated beams (load acting normal to the edge of laminations). In horizontally laminated beams, edge joints need not be edge-glued. Edge gluing is required in vertically laminated beams. Edge and face gluings are the simplest to make, end gluings the most difficult. FIGURE 10.27 Plane sloping scarf. Although no longer used in the glulam industry, a plane sloping scarf (Fig. 10.27), in which the tapered surfaces of laminations are glued together, can develop 85 to 90% of the strength of an unscarfed, clear, straight-grained control specimen. Finger joints (Fig. 10.28) are less wasteful of lumber and hence are widely used by the glulam industry. Quality can be adequately controlled in machine cutting and in high-frequency gluing. A combination of thin tip, flat slope on the side of the individual fingers, and a narrow pitch is desired. The length of fingers should be kept short for savings of lumber, but long for maximum strength. Typical finger joint lengths are 1
11/4
. The usefulness of structural glued-laminated timbers is determined by the lumber used and glue joint produced. Certain combinations of adhesive, treatment, and wood species do not produce the same quality of glue bond as other combinations, although the same gluing procedures are used. Thus, a combination must be supported by adequate experience with a laminators gluing procedure. The only adhesives currently recommended for wet-use and preservative-treated lumber, whether gluing is done before or after treatment, are resorcinol and phenolresorcinol resins. Melamine and melamine-urea blends are also used for highfrequency curing of end joints. Glued joints may be cured with heat by several methods. Radio-frequency (RF) curing of glue lines is used for end joints and for limited-size members where there are repetitive gluings of the same cross section. Low-voltage resistance heating, where current is passed through a strip of metal to raise the temperature of a glue line, formerly was used for attaching thin facing pieces. The metal could be left in the glue line as an integral part of the completed member. Printed electric circuits, in conjunction with adhesive films, and adhesive films impregnated on paper or on each side of a metal conductor placed in the glue line are other alternatives. Preheating the wood to ensure reactivity of the applied adhesive has limited application in structural laminating. The method requires adhesive application as a wet or dry film simultaneously to all laminations, and then rapid handling of multiple