Blog Archives

Moisture Testing

Posted by on 24/ 11/ 15

Ensuring that materials are dry is essential in healthy building. Building materials can be ruined by moisture damage. The follow­ing four building practices can cause warp­ing, deterioration of materials, and microbial growth:

1. Application of finish flooring materials over insufficiently cured concrete slabs

2. Failure to quickly and thoroughly dry out precipitation that enters an unfinished structure

3. Installation of wood members with a mois­ture content greater than 17 percent

4. Enclosure of walls containing wet-applied insulation systems, such as cellulose or spray foams, before they are properly cured

It is not always possible to detect by visual in­spection whether a material is wet...

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Drainage Layers

Posted by on 24/ 11/ 15

A rather common subsurface drainage system used to remove the infiltrated/seepage water from the pavement structures is by providing a permeable layer. Permeable layers should be at least 10-15 cm thick and extend under the full width of the roadway. They can be used under both concrete (PCC) and asphalt (AC) pave­ment surfaces. Permeable bases are usually located just above the subgrade and are discussed in more detail in the second part of Section 13.3.6. Permeable unbound granular bases must be separated from high plasticity subgrade soils by mean of geotextiles or impervious materials.

The drainage layer should drain into a longitudinal drainage pipe. In order to encourage the lateral flow of water, a minimum cross-fall should be considered, of, at least, 2%...

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Low-Energy Lighting: The Latest Bulb Technologies

Posted by on 24/ 11/ 15

Подпись: П MAXLITE © III

COMPACT FLUORESCENT LAMPS

An aversion to fluorescents is understand­able because they have been so awful for so long. They didn’t dim easily; they buzzed and gave off weird colors. And sadly, the push to offer CFLs at a price point close to that of a standard incandescent household bulb has given fluorescents a bad name all over again. The color of these cheap CFLs is poor, they burn out prematurely, and they aren’t dimmable. There are much bet­ter products on the market. Be prepared to pay more, but they will be worth it. Top – of-the-line screw-in CFLs by manufacturers like MaxLite™ and Earthtronics® (see "Bulb Sources," on p. 154) offer an energy – efficient, dimmable (down to 30%) light source that can be controlled by a standard incandescent dimmer.

A new category of CFL is the ...

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SMA ON BRIDGE DECK STRUCTURES

Posted by on 24/ 11/ 15

Surfacing on bridge structures is not, and should not be, like that of a standard pavement on a soil subgrade. The essential difference lies in a different mode of operation. There are special circumstances that must be considered, including the following:

• The cooling and warming effect developing from underneath the bridge deck pavement caused by changes in air temperature under the steel struc­ture and faster changes of the pavement temperature due to wind action, which occurs faster and more intensely than in case of a pavement on grade

• Structural deflections of a bridge’s deck caused by passing vehicles

• The amplitude of bridge deck vibration, which is much higher than that of conventional road pavement

• Much more intensive applications of deicers, leading to the quick d...

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Company Goals

Posted by on 24/ 11/ 15

Job site goals need to be directed by overall company goals, which will vary depending on the owner’s desires. Here are some examples:

Sample Company Goals:

1. To provide income for framers and the company

2. To provide a safe and enjoyable work environment

3. To coordinate with the general contractor’s schedule and needs

4. To produce high-quality framed buildings

5. To grow the company

6. To develop framing skills

Communication

Communication is to a lead framer what a hammer is to a framer—one of your most important tools. Before you were a lead framer, you had to communicate with only one person—most likely the lead contractor or superintendent. As a lead framer, you will be communicating with these same people, but also possibly with the architect, engineer, owner, and the crew.

Ea...

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STEP 8 PAINT THE EXTERIOR SIDING AND TRIM

Posted by on 24/ 11/ 15

On our Charlotte house, we didn’t have a lot of exterior painting to do. We installed vinyl siding, soffits, and windows and covered fascia and rake boards with aluminum cladding. But we still needed to do a bit of exterior paint­ing (door casings and doors, for example). On houses with more exposed wood, you should know how to paint the exterior correctly. Here are some guidelines you can use to make sure your exterior finishing work will look good and hold up well.

Choose an exterior finish

Wood siding, such as shingles or clapboard, is often better off when finished with stain rather than with paint. Solid-color exterior stain gives wood a paintlike appearance, but it does not crack or peel the way paint can...

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Gardermoen Airport in Oslo

Posted by on 24/ 11/ 15

During the 1990s, a few airfield pavements paved with SMA mixtures were constructed in Norway. Various binders and additives were used, depending on the climatic zones in which they were placed. The biggest of these airfields with an SMA pavement is Gardermoen near Oslo. On Gardermoen’s runways, 4-cm thick SMA mix of 0/11 mm were placed on the western runway) and 4-cm thick SMA mix 0/16 mm was placed on the eastern runway. Two SMA runways, 3300 m and 2950 m long, were constructed there with styrene-butadiene-styrene (SBS) modified binders (Larsen, 2002).

13.1.3 Johannesburg Airport

In 1999 the following comparative trial sections of different mixes applied in new asphalt wearing courses were laid down at the international airport in Johannesburg, South Africa (Joubert et al., 2004):

• 0/...

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TIPS FOR THE PAINT STORE

Posted by on 24/ 11/ 15

Before heading for the paint store, calculate the square footage of surfaces to be painted. Then compare those figures with the coverage figures listed on the paint containers. Unless a wall is preponderantly glass, don’t bother to subtract the square footage of windows and glass doors from your total. You’ll eventually need the extra paint for touchups.

TIPS FOR THE PAINT STORE

Although some artists can hand – tint 5-gal. quantities to match existing paint, the rest of us should rely on paint-store mixologists. They have color charts, recipes, and accurate measuring tools.

The blue object at the lower right is a power-drill paint mixer.

 

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to Thin о

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Подпись: OR NOT TO THIN?Подпись:Подпись: PROnP Less expensive than finish paints, tinted primers also hide more and therefore ensure a more uniform finish color. So you can save money by having your paint store tint the primer closer to the color of the finish coat. This is especially true if you're painting over existing paint that's darker than the new paint. 1111 Подпись: Predicting the coverage of stains is more difficult, especially if the wood is untreated. Add 15 percent to 25 percent if you need to special- order the stain and must wait more than a day or two for delivery. That way, you'll be ensured of enough stain to finish the job. If your paint job will be large, save money by buying 5-gal. rather than 1-gal. quantities. However, if it's more cost-effective to buy only a few 1-gal. cans, ensure uniform color by mixing their contents in a clean, empty 5-gal. bucket. This way, you'll avoid finishing one can in the middle of a wall and resuming with a noticeably different hue. Подпись: You may be able to extend the life of a filter cartridge by removing it from the mask, placing it in a sealed plastic bag, and putting it in the refrigerator. If you leave cartridges in a mask merely hanging in your shop or garage, they will be dead in about 3 weeks.Подпись: bntortnf tht cityПодпись:Подпись: Protect your lungs whenever you sand, scrape, or strip paint-even if there's plenty of fresh air. While heating old paint for scraping, this worker is wearing a lightweight dust mask with P100 particulate filters.image896Speaking of mixing, have your paint store mechanically shake the paint for you—unless, of course, the man...

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Superimposed versus Terraced Structures

Posted by on 24/ 11/ 15

There are instances when one MSE wall is built on top of another. In certain instances, these walls can be considered to be two independent structures, each requiring its own internal design and external stability. The global stability of the slope must be suffi­ciently stable so as not to undermine the stability of the entire embankment.

Figure 8.36 shows a superimposed structure. The walls are such that the load of the upper wall level serves as a surcharge load on the lower wall. Each wall is independently designed.

FIGURE 8.35 Foundation pressure for MSE wall calculated by the AASHTO method based on Meyerhof. (From the Reinforced Earth Co., with permission)

FIGURE 8.36 Superimposed MSE walls. (From the Reinforced Earth Co., with permission)

This design approach does not ...

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Culture Collection

Posted by on 24/ 11/ 15

Special moist, sterile swabs called culturettes are good for this type of sampling. The cul – turette is presterilized and comes with a fluid- filled glass ampoule to provide just the right amount of moisture. The ampoule and swab are housed in a sterile plastic tube. About one minute before collecting the sample, squeeze the area of the tube over the ampoule to break the ampoule and release the fluid, which then soaks the cotton swab. Slide the moistened swab from its sterile tube and use it to wipe one square inch of the area to be tested. Then in­sert the swab back into the sterile plastic tube for shipment to the lab. Since this method uses liquid, the fungal spores will be hydrated and begin to colonize...

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