Blog Archives

Mixing: Basic Information

Posted by on 17/ 11/ 15

Mixing the components of a bituminous mixture, proportioned by weight from hot – bins, in a batch asphalt plant takes place in a pugmill. Contemporary batch plants have pugmills of various sizes, usually from 1 ton to 8 tons. Despite the different sizes of pugmills and the resulting output of the plants, mixing time, by and large, remains at the same level for all plants (USACE Handbook, 2000). Determining the suitable amounts of materials to batch given the pugmill’s volume is quite a significant step

TABLE 9.1

Recommended Maximum Production Temperatures of an SMA Mixture for example binders according to various Regulations

Mixing: Basic Information Подпись: Germany ZTV Asphalt-StB 07 (Table 5) <190 <180
Подпись: EN 13108-5:2006 (Table 16) <190 <180 <170
Mixing: Basic Information
Подпись: <180 (PMB 25/55-55)
Mixing: Basic Information
Подпись: <190 (PMB 45/80-x)
Mixing: Basic Information

Maximum Mixture Temperature in Asphalt Plant (°С)

Note: PMB = Polymer modified binder.

and is one of the decisive actions und...

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DOORS, WINDOWS, & STAIRS

Posted by on 17/ 11/ 15

Doors and windows are two of the few finish items that framers sometimes handle. It is important that time and care are taken to ensure they are installed in a proper, professional manner. Put your framing hammer in the toolbox and use, instead, a lighter, smoother-faced trim hammer and a nail set.

Exterior, pre-hung doors are the type covered in this chapter. They are the ones framers most commonly work with, and most of the skills involved in hanging them will carry over to the hanging of interior doors. The first door you hang on any job will give you the most difficulty. If you have more than one door to hang, do them one after the other; each door will go in a little easier than the one before.

Nail-flange windows and sliding glass doors will vary depending on the manufacturer...

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Production process

Posted by on 17/ 11/ 15

Suppose that we have already developed the job mix formula and that well-perform­ing batching devices, a screen deck, balances, and so on are at our disposal. Then we are ready to start production. A common occurrence with starting up an asphalt plant is the instability of the mixture temperature during the first production period. Therefore one should take into account that some batches will be underheated, while others will be slightly overheated. Such waste material should be rejected.

9.3.1 SMA Production Temperature

Two components of an SMA mixture must be heated—the aggregate and the binder...

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SITE-BUILT FIXED WINDOWS

Posted by on 17/ 11/ 15

Storm sash made today are usually fitted to aging single-glazed windows. The storm sash protects the existing window from the weather and also improves the thermal performance of the window.

Usually made of aluminum, storm sash are custom fit to the exterior face of the existing window. Many are operable from the interior and are fitted with screens. Depending on how they are installed, storm sash can either significantly extend the useful life of old windows or actually contribute to their deterioration. A proper installation depends on numerous factors including the climate and the detailing of the original window.

SITE-BUILT FIXED WINDOWS

New custom wood windows can be manufactured with single glazing if fitted with storm sash...

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Concluding Remarks

Posted by on 17/ 11/ 15

Road-related pollution sources include 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 (e. g. from vehicle corrosion, cargo spills and road equipment), hydrocarbons (from fuels, lubricants and bitumen), nutrients (generated from motor exhausts), particulates (from pavement and exhausts) and de-icing salt. Runoff, splash/spray and seepage through the road construction and the soil are major transport routes of pollutants from the road to the environment.

Pollutant transport through road materials and soils in the road environment is governed by the same physical processes as those occurring in soils elsewhere...

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REMAINING TABLES

Posted by on 17/ 11/ 15

The remaining tables are different in content, but the procedures for using them are the same. Once you know the number of bedrooms and bathrooms for a dwelling, you can quickly and easily determine the minimum require­ments for a water heater. You have just seen how simple the tables are. When you have a water heater to size, just refer to the tables in this chapter (Fig. 7.4, to 7.10) or the tables in your local codebook.

Number of bedrooms

2

3

4

5

Storage capacity (gallons)

30

40

40

50

Input in Btuh

36,000

36,000

38,000

47,000

Draw (gallons per hour)

60

70

72

90

Recovery (gallons per hour)

30

30

32

59

FIGURE 7.4 ■ Water heating sizing table for gas heaters (minimum recommendations). Assume 2 to 21/2 bathrooms.

Numbe...

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AFOSM reliability analysis for nonnormal correlated stochastic variables

Posted by on 17/ 11/ 15

For most practical engineering problems, parameters involved in load and re­sistance functions are correlated nonnormal random variables. Such distribu­tional information has important implications for the results of reliability com­putations, especially on the tail part of the distribution for the performance function. The procedures of the Rackwitz normal transformation and orthogo­nal decomposition described previously can be incorporated into AFOSM reliability analysis. The Ang-Tang algorithm, outlined below, first performs the orthogonal decomposition, followed by the normalization, for problems involv­ing multivariate nonnormal stochastic variables (Fig. 4.12).

The Ang-Tang AFOSM algorithm for problems involving correlated nonnor­mal stochastic variables consists of the followin...

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STEP 7 SHEATHE THE ROOF

Posted by on 17/ 11/ 15

Sheathing a roof is much like sheathing a floor, except that the deck is sloped, not flat, and you work at least 10 ft. off the ground. Anyone who has worked in the construction trades for more than a few years has heard stories about someone who has fallen from a roof—or has seen it happen. I was sheath­ing a roof many years ago on a cool morning with a bit of frost on the ground. The sunny side of the roof had no frost. Without think­ing, I stepped onto the shady side of the roof and was immediately careening down a fairly steep pitch, heading for doom. Fortunately, I had my straight-clawed hammer in my hand...

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Patching Foundation Cracks

Posted by on 17/ 11/ 15

Determine the cause of the crack and fix that first; otherwise the crack may recur. Shallow foundation cracks less than % in. wide are usually caused by normal shrinkage and needn’t be patched, unless their appearance disturbs you or they leak water. However, you should repair any cracks that go all the way through the foundation: Probe with a thin wire to see if they do.

Of the many crack-repair materials, there are three main types: cement-based, epoxy, and polyurethane foams. When working with any of these materials, wear dis­posable rubber gloves, eye protection, and a respirator mask with changeable filters.

Cement-based materials such as hydraulic cement are mixed with water and troweled into cracks...

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European Legislation

Posted by on 17/ 11/ 15

Across Europe, the legislation on the influence of road and road traffic on water and water bodies and associated ecosystems is wide and complex. European legislation in general prohibits water pollution and limits influences on the water biotopes. These general rules are transferred into national legislation in very different ways. Realization of these rules depends on the country’s prevailing natural conditions (e. g. climatic regime), uses of water and technical regulations concerning road plan­ning, design, construction and maintenance. In general, water pollution from roads is regulated in two main groups of legislation: environmental law and construction law. This section refers to environmental law.

Water is one of the most comprehensively regulated areas of the EU environmen­tal...

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