Blog Archives

Materials CHOOSING CAULKS AND SEALANTS

Posted by on 21/ 11/ 15

IF YOU WALK DOWN the caulk and sealant aisle at any well-stocked hardware store or home center, it’s easy to feel overwhelmed by the variety of products available. For quite a few years now, the terms "caulk" and "sealant" have been used interchangeably. In technical terms, sealants are supposed to be more flexible than caulks, meaning that they are able to expand and contract with the movement of materials. But even caulk and sealant manufacturers have different definitions for these materials. For this reason, it’s smart to ask local builders and knowledgeable building – material suppliers which caulks and sealants are recommended for various jobs.

Although manufacturers haven’t cleared up the distinction between caulks and sealants, they have improved their labeling with regard to speci...

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STEP 1 Seal Penetrations in the Walls, Ceilings, and Floors

Posted by on 21/ 11/ 15

When you think about sealing a house, remember how much frigid air can go through a small opening in a sweater or a jacket. Even a tiny hole in a woolen mitten can make your finger numb with cold. The same thing can happen in a house. We had single – glazed, double-hung windows in that old prairie home where I grew up. In the spring, the windows were nice—we could open them wide to let in fresh breezes and the songs of meadowlarks announcing warmer weather. In the winter, though, that loose-fitting sash was a fright. My mother gave us thin strips of cloth to stuff between the window frame and the sash in hopes of slowing the icy winds that would soon roll down from the north.

Today, we have the materials and the know­how to seal a house effectively...

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Repeated Load Triaxial Testing of Unbound Granular Materials

Posted by on 21/ 11/ 15

The repeated load triaxial testing (RLT) (also known as the cyclic triaxial test) method is commonly used to establish the mechanical characteristics of granular materials. During the testing, a cylindrical specimen is compacted to a desired level and then tested by applying confining and vertical stresses. Two variants exist:

• a constant confining pressure (CCP) method; and

• a variable confining pressure (VCP) method.

In the CCP-method the sample is initially subjected to a hydrostatic confining pres­sure ac, which induces an initial strain ec (unmeasured in the test, but it is the same in

Fig. 10.1 Stresses in an unbound granular material layer. (a) Typical pavement structure and stresses, (b) induced stresses in a pavement element due to moving wheel load (Erlingsson, 2007)
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Transport of a Mixture to the Working Site

Posted by on 21/ 11/ 15

When it is cold and the construction site are far away, we usually console ourselves with the idea that the mixture is hot inside so the cool crust may be somehow stirred into the hot mix and warmed up in the paver. The mix really is hot inside, as shown in Figure 11.12. Typical cracks in the cool crust formed on the surface of the trans­ported mixture and its deeper cooling down by the truck’s sideboards may also be noticed. That is why it is always worth using trucks that have well-insulated boards and are tightly covered.

In cold seasons there are little chance that delivered mix will have thermal uni­formity. Usually after discharge of the mixture into the paver hopper there are many cool or poorly heated fragments in the mixture...

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FACILITIES FOR HANDICAP TOILETS

Posted by on 21/ 11/ 15

Let’s talk about the facilities for handicap toilets (Fig. 10.8). When a handi­cap toilet is installed in a privacy compartment, the minimum net clear open­ing for the compartment must be at least 32 inches wide. The door of the
compartment must swing out, away from the toilet. The width of such a com­partment should be 36 inches, with a depth of 60 inches. Unlike a standard toilet where the side clearance is 15 inches, handicap toilets require a side dis­tance of 18 inches.

Подпись:

FACILITIES FOR HANDICAP TOILETS

Grab bars must be installed at a height of no less than 33 inches and no more than 36 inches above the finished floor. The bars must have a minimum length of 42 inches. They must be mounted on both sides of the compart­ment...

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OTHER CONSIDERATIONS

Posted by on 21/ 11/ 15

In addition to the choices about pitch, shape, and structure discussed above, many other decisions con­tribute to the overall performance of the roof. These include selection of sheathing, underlayment, and roofing material; eave, rake, and flashing details; gutters and downspouts; and insulation and ventilation of the roof assembly. All of these issues are discussed in this chapter.

Подпись: RiDGE
Rafter sizes are usually 2×6, 2×8, 2×10 or 2×12, and spacing is usually 16 in. or 24 in. o. c. Species of wood vary from region to region. Rafter sizing depends pri­marily on span, spacing, roof loads, and sometimes on required insulation depth.

For a rafter-span table, see 131A.

@ ROOF FRAMING

Подпись: RAFTER SUPPORT AT TOP OF RAFTER Подпись: RAFTER SUPPORT AT EAVE SEE 131AПодпись:OTHER CONSIDERATIONS

Подпись: A STICK FRAMING Terminology

Stick-framed rafters may be supported by the walls of the building, by a structural ridge beam, or by p...

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Mixture Production in an Asphalt Plant

Posted by on 21/ 11/ 15

When storing a finished, hot mixture in a silo, the mixture closest to the walls of the container is subject to gradual cooling. As storage time increases, the amount of cool mixture is likely to rise substantially. If the SMA contains modified binder, its stiffening process proceeds much faster. Moreover, we may face additional trouble with cool mixture stuck to the walls of the silo unless the silo is heated. Also, if the silo chutes are not heated, problems with discharging the mixture out of the silo can occur.

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ЕРА Takes a "Stand" on the Carpet Controversy

Posted by on 21/ 11/ 15

In October 1987, the EPA installed carpet at its headquarters in the Waterside Mall in Washington, DC. A total of 1,141 complaints were received re­garding adverse health effects related to the new carpet.3 These complaints included decreased short-term memory, loss of concentration, confu­sion, anxiety, headaches, joint and muscle pains, rashes, digestive disorders, reproductive abnor­malities, asthma, insomnia, chronic fatigue, and multiple chemical sensitivities. Dozens of workers remained permanently disabled. After the EPA in­vestigated these carpet complaints from its head­quarters building, it published a report showing a positive correlation between the EPA worker com­plaints and the new carpet.6

Despite the results of its own study, and the removal of 27,000 square yards of ...

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Suction/Saturation Control

Posted by on 21/ 11/ 15

Although there are a wide variety of tests for assessing soils and road materials, any serious investigation will need to know the mechanical behaviour of these materials when subjected to repeated loading that simulates the effects of trafficking and under moisture conditions (water content and suction) that simulate that found in the layers of the road construction and embankment. Various devices have been developed including the k-mould (Semmelink et al., 1997) and the Springbox (Edwards et al., 2004), but the cyclic triaxial test has secured the greatest following for material assessment over many years and is now the subject of European, US and Australian standards (CEN 2004, AASHTO 2000, Standards Australia 1995). It is the use of this test that is described in this section.

In labor...

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Problems of Manufacture and Transportation

Posted by on 21/ 11/ 15

Most questions related to maintaining a suitable temperature during the mixture’s manufacture have been regulated by commonly known technical specifications (e. g., standards, guidelines). These questions are discussed in Chapter 9. Simply speaking, there are two main problematic instances in the matter of SMA manufac­ture temperatures—when the temperatures are too low or when the temperatures are too high.

Too low a manufacturing temperature of a mix prevents the formation of a correct and complete asphalt binder film. Too low a temperature can be visually recognized; aside from visible uncoated aggregate pieces, the appearance of the mixture seems to be matte...

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