Blog Archives

Sources

Posted by on 16/ 11/ 15

Pollution sources include five main groups: traffic and cargo, pavement and embank­ment materials, road equipment, maintenance and operation, and external sources. Road and traffic pollutants having received the greatest attention include heavy metals, hydrocarbons, nutrients (mainly nitrogen), particulates and de-icing salt (Table 6.1). Recently, precious metals worn from catalytic converters have also been given attention. In addition to these pollutants, a range of gaseous pollu­tants is emitted as a result of fuel combustion. These are to a large extent aerially transported away from the road area, and this issue is beyond the scope of this overview.

The amount of pollutants originating in road and traffic depends on several aspects related to road design, road materials, road mainte...

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Raise exterior butt walls next

Posted by on 16/ 11/ 15

Raise exterior butt walls next

Once you’ve finished with the exterior

Подпись: STEEL STRAPS PROVIDE EXTRA HOLDING POWER. Metal ties like this one are sometimes required by code. They anchor the wall framing to the floor andRaise exterior butt walls next

Подпись: foundation, keeping the house together under adverse conditions.
Подпись: TACK THE DOUBLE TOP PLATE. When raising interior walls, it often helps to tack part of the double top plate to the wall, as shown here, until after the wall has been raised. Later, this short section of double top plate can be positioned to overlap the top plate in an adjacent wall.

16d nail between each stud. Be sure to drive a 16d nail close to each king stud. Drive plate nails into the rim joist or into a floor joist. Nails driven through the subfloor alone don’t have nearly as much holding power as those

through walls, its time to raise the exterior butt walls. Remember that vou want the butt walls’ double top plates to be about 3/ in. longer than the Lop plates (5’A in. for 2×6 walls) so that they will lap over the through walls’ top plates. This can make it difficult to

Raise exterior butt walls next

Подпись: IT'S A HOUSE! When the last wall has been raised, something special happens. What was once just a jumble of framing lumber on the deck all of a sudden feels like a house with real rooms.

raise the butt walls, though, because the dou­bletop plate sticks out at both ends.

There are a couple of tricks for making it easier to raise these and other butt walls.

One approach is to double-plate the entire butt wall ex...

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The Open-Cell vs. Closed-Cell Debate

Posted by on 16/ 11/ 15

In most closed-cell foams, such as those made by Corbond®, an HFC blowing agent is captured in the foam’s cell structure. This gas has a better thermal performance than the air-filled open-cell foam and gives it a higher overall R-value. However, while HFC – blown closed-cell foam might initially have an R-value as high as R-8 per in., its R-value diminishes as the blowing agent evaporates through cell walls and is replaced by air. Closed-cell foam’s "aged" R-value is roughly R-6 per in. Some manufacturers produce water-blown closed-cell foams. These foams have the same performance properties as HFC-blown foam, but slightly lower R-values, at around R-5.5 per in.

Closed-cell foam’s greater density, 2 lb. per cu. ft. compared with open cell’s 1/2 lb. per cu. ft...

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Preparation of Samples

Posted by on 16/ 11/ 15

Preparation of samples for an SMA recipe is conducted according to the Marshall method, with a compaction effort of 2 x 50 blows, or in a gyratory compactor, where the number of rotations are selected in such a manner that the specimen bulk density is similar to results obtained from the Marshall method. While designing SMA with the use of the gyratory compactor, the maximum density of the mix is experimen­tally established.[42] 7.4.3 Design Method

The applied method of SMA design in the Netherlands belongs to the group of volu­metric methods. However, the assumption of a constant amount of binder in a mix makes a significant difference in comparison with other volumetric methods...

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Context

Posted by on 16/ 11/ 15

Roads and road traffic influence the natural environment in a complex manner. At the same time as roads serve the transport of people and goods, roads take land and form barriers to the movement of people, animals and water in the land­scape. A range of pollutants is emitted from roads and traffic and spread to the environment.

The pollutants are transferred away from the road mainly via road-surface runoff and aerial transport but also with percolation through the pavement. Runoff pol­lution is a much studied issue whereas much less is known about pollutants per­colating through the pavement and embankment into the groundwater and surface waters.

The vast majority of the pollutants stay close to the road where they accumu­late in vegetation, soil and also animals...

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Cob and Other Wet Clay Techniques

Posted by on 16/ 11/ 15

Throughout history, several methods for mud construction have evolved using wet mud fashioned into various shapes and stacked onto the wall while still plastic. The mud is then fused with the layers below it to create a monolithic wall. This type of construction has lent itself to laybuilders because it requires no formwork or special equipment and no pro­cessing other than onsite mixing. Two mod­ern innovations in this building method are of note.

In Germany, Gernot Minke has devel­oped a method called stranglehm for build­ing with extruded clay profiles. Casein or whey is added to the clay mixture to make the clay more water resistant. Minke has created a mechanized extrusion apparatus for use at the building site that can produce about six feet of material per minute...

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DECK SURFACES AND DECK OVERLAYS

Posted by on 16/ 11/ 15

New Construction. Some agencies use asphalt concrete overlays on new decks and protect the deck with a waterproofing membrane below the asphalt overlay. Currently, however, concrete-wearing surfaces are more popular on new bridges than asphalt concrete. Concrete surfaces may be placed as an integral part of the structural bridge deck (monolithic), or placed as bonded overlays of various types including dense concrete, latex-modified concrete, and silica fume concrete (see Art. 4.5.1).

Repair of Existing Bridge Deck Surface. The concrete overlays discussed above can be used, in combination with patching of spalled areas, as a means of repairing deteriorated existing bridge decks...

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Raise exterior butt walls next

Posted by on 16/ 11/ 15

Once you’ve finished with the exterior through walls, it’s time to raise the exterior butt walls. Remember that you want the butt walls’ double top plates to be about 3/4 in. longer than the top plates (5/4 in. for 2×6 walls) so that they will lap over the through walls’ top plates. This can make it difficult to raise the butt walls, though, because the double top plate sticks out at both ends.

There are a couple of tricks for making it easier to raise these and other butt walls. One approach is to double-plate the entire butt wall except for a short section—say, 4 ft. or 5 ft.—at each end. Cut these short pieces and tack them to the wall to keep them close at hand (see the bottom right photo on p. 103). Then nail them on after raising the wall...

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EXAMPLES FROM THE DEMONSTRATION PROJECTS

Posted by on 16/ 11/ 15

Подпись: JVAH Walls and PartitionsMost JVAH sites used some aspects of Optimum Value Engineered wall systems to minimize costs. The most commonly used techniques were in-line framing with 24-inch stud spacing, single top-plates, 1×4 bottom plates, two-stud outside corners, metal drywall clips instead of wall and ceiling nailers, and elimination of headers and jack studs in nonbearing walls.

Подпись: Christian County, Kentucky

Besides using OVE techniques which saved $448 per unit, Pup Robertson saved 3,000 bricks per house by starting the brick at the bottom of the wood floor instead of below grade, eliminating gable brick and reducing the wall height to 7’6"; moreover, since each house required less brick than normal, he was often able to buy odd-lot quantities at substantial savings. These techniques saved $1,685 per unit on brick veneer.

EXAMPLES FROM THE DEMONSTRATION PROJECTS

Подпись: Fairbanks, AlaskaTom Webb use...

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SUMP VENTS

Posted by on 16/ 11/ 15

Sump vents, the ones used to vent a sump system, are calculated on a basis of a pump’s discharge capacity. Tables are often provided for this type of sizing. See Figure 5.37 for an example of such a table. Using a table like this one, you can quickly and easily size a vent for a sump. As long as you know the discharge rate of the pump being used in the sump, the rest of the work is simple.

SUMP VENTS

SUMP VENTS
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