p
150  9000 (9.5) T where p
lateral pressure, psf R
rate of filling, ft /h T
temperature of concrete, F See Fig. 9.6a. For columns, the maximum pressure pmax is 3000 psf or 150h, whichever is less, where h
height, ft, of fresh concrete above the point of pressure. For walls where R does not exceed 7 ft /h, pmax
2000 psf or 150h, whichever is less. For walls with rate of placement R  7, p
150 2800 (9.6) where pmax
2000 psf or 150h, whichever is less. See Fig. 9.6b. The calculated form pressures should be increased if concrete unit weight exceeds 150 pcf, cements are used that are slower setting than standard portland cement, slump is more than 4 in. with use of superplasticizers, retarders are used to slow set, the concrete is revibrated full depth, or forms are externally vibrated. Under these conditions, a safe design assumes that the concrete is a fluid with weight w and pmax
wh for the full height of placement. 9.18.2 Design Vertical Loads for Horizontal Forms Best practice is to consider all known vertical loads, including the formwork itself, plus concrete, and to add an allowance for live load. This allowance, including workers, runways, and equipment, should be at least 50 psf. When concrete will be distributed from overhead by a bucket or by powered buggies, an additional allowance of at least 25 psf for impact load should be added. Note that the weight of a loaded power buggy dropping off a runway, or an entire bucket full of concrete FIGURE 9.6 Internal pressures exerted by concrete on formwork: (a) column forms; (b) wall forms. dropped at one spot, is not considered and might exceed designs based on 50- or 75-psf live load. Formwork should be designed alternatively, with continuity, to accept such spot overloads and distribute them to various unloaded areas, or with independently braced units to restrict a spot overload to a spot failure. The first alternative is preferable. 9.18.3 Lateral Loads for Shoring Most failures of large formwork are progressive, vertically through several floors, or horizontally, as each successive line of shoring collapses like a house of cards. To eliminate all possibility of a large costly failure, the overall formwork shoring system should be reviewed before construction to avoid the usual house-of-cards design for vertical loads only. Although it is not always possible to foresee exact sources or magnitudes of lateral forces, shoring for a floor system should be braced to resist at least 100 lb / lin ft acting horizontally upon any of the edges, or a total lateral force on any edge equal to 2% of the total dead loads on the floor, whichever

Figure 1 Well blended Figure 2 Poorly blended Working with Bricks Brick Technical Manual 19 2.4 Mortar Joints Mortar joint style also plays a major part in determining the overall appearance of a building. The different styles possible are shown below. Properly filled and tooled joints improve the durability, weather proofness and sound performance of brickwork. Raked and ironed joints are used to achieve the character look in a new home. Flush joints will increase the impact of the mortar colour when a contrasting colour is chosen. For bricks with a bevelled edge, it is recommended that a raked joint be used. It should be noted that raked or recessed joints should not be used in severe marine environments and should be avoided in applications where durability is critical. Shallow Ironed (Rolled) Deep Ironed (Rolled) Struck Flush Weather Struck Raked Beaded Pointing Tuck Pointing Joint thickness and tolerances The standard thickness for a mortar joint is 10 mm. However joints must vary in thickness to allow for the natural size variation of clay bricks. AS 3700 allows a deviation from the specified thickness of bed joint of 3 mm.

Saturated: S  100% Relative Density. The relative density is a measure of the density state of a nonplastic soil. The relative density can only be used for soil that is nonplastic, such as sands and gravels. The relative density (Dr in %) is defined as: e
e D (%)  100 max (6.7) r e
e max min where emax  void ratio corresponding to the loosest possible state of the soil, usually obtained by pouring the soil into a mold of known volume emin  void ratio corresponding to the densest possible state of the soil, usually obtained by vibrating the soil particles into a dense state e  the natural void ratio of the soil The density state of the natural soil can be described as follows: Very loose condition Dr  0 to 15% Loose condition Dr  15 to 35% Medium condition Dr  35 to 65% Dense condition Dr  65 to 85% Very dense condition Dr  85 to 100% The relative density (Dr) should not be confused with the relative compaction (RC), which will be discussed in Art. 6.10.1. Useful Relationships. A frequently used method of solving phase relationships is first to fill in the phase diagram shown in Fig. 6.7. Once the different mass and volumes are known, the various phase relationships can be determined. Another approach is to use equations that relate different parameters. A useful relationship