Blog Archives

Install the wall cabinets

Posted by on 25/ 11/ 15

Wall cabinets are usually installed with their bottom edges 54 in. from the floor, or 18 in. above a countertop (see the illustration on the facing page). Mark a level line for the wall cabinets with a soft pencil, so that it can be erased or easily cov­ered with paint. If there is a kitchen soffit make sure the cabinets are secured to the walls, with their tops fitting snugly against the soffit.

Before hanging wall cabinets, remove the doors and shelves to make the cabinets lighter. Just as with base cabinets, start in a corner and install every unit level and plumb. Use a T-support or something similar to hold a cabinet in place until it is attached to the wall (see the photo at left). Wall cabinets should be set directly above corresponding base cabinets...

read more

Load Combinations

Posted by on 25/ 11/ 15

Noise barriers can be designed by working-stress design methods or load factor design. For the working-stress design method, the following load combinations should be considered:

Group I: D + E + SC

Group II: D + W + E + SC

Group III: D + EQD + E

Group IV: D + W + E + I

dead load

lateral earth pressure live load surcharge wind load seismic load ice and snow load

For load combination I, the stresses are limited to 100 percent of the basic allowable stresses. For load combinations II, III, and IV, the stresses are limited to 133 percent.

9.9.2 Design Criteria

The AASHTO Guide Specifications state that, for the design of noise barriers in concrete, timber, or steel, the design should conform to either the AASHTO Bridge Specifications or an industry-recognized design specification...

read more

Electric Fields

Posted by on 25/ 11/ 15

Wiring to Reduce Electric Fields

In Germany, Bau-Biologists have long been concerned about the negative health effects associated with exposure to electric fields. In the United States, mainstream science has given little credence to the notion that electric fields pose a health threat and remains skepti­cal in spite of continuing evidence of biologi­cal effects.

A 1996 study by the Ontario Hydroelectric Company indicated a greater than sevenfold increase in cancers among long-term work­ers exposed simultaneously to magnetic and high electric fields.2 The study suggests that the presence of electric fields potentiates the health impact of magnetic fields. Additional data published in 2000 support the role of electric field exposure in leukemia...

read more

Homogeneity and Quality of Coating with Binder

Posted by on 25/ 11/ 15

The SMA mixture should be homogenous and completely coated with binder when discharged from the pugmill. There should be no evidence of agglomeration (balling) of the fine aggregate.

14.5.4 Void Content

Void content is one of the essential properties of a compacted SMA mix. Much attention was paid to this subject in the previous chapters, particularly in Chapters 6 and 7. Establishing the method of sample preparation and suitable conditions (compactive effort and compaction temperature) is necessary for the proper deter­mination of air voids in compacted samples. The standard categorizes of minimum and maximum void contents in SMA samples to be selected in an NAD are as follows:

• Minimum void content in SMA samples range from 1.5 to 6% in increments of 0.5% (i. e., Vmin= 1.5, 2. 2.5…)[...

read more

Pavement Underdrains

Posted by on 25/ 11/ 15

In excavated areas and cuttings where the longitudinal slope is more than 3%, a longitudinal water flow may appear fed by water from under the pavement that is

Water*………………. ………………..

table with drain ^ |

separate from the flow in channels, gutters and gully’s. In these cases, the inclusion of pavement underdrains (Fig. 13.26), installed transversally under the pavement, can be used, in order to collect all subsurface waters. These kinds of drain are best constructed in transition areas and, in areas of excavation or fill, placed centrally to improve the rapid flow of the infiltrated water. In sandy soils they should be placed with a spacing between 20 and 25 m while, in very clayey soil, these distances should be reduced to about 5 m.

It is advisable that these transverse drains b...

read more

STRUCTURAL DESIGN

Posted by on 25/ 11/ 15

9.9.1 Noise Barrier Design Loads

Wind Loads. In most cases, the wind load represents the main load. The design pressure depends upon the wind velocity, which should be based upon a 50-year mean recur­rence interval (Fig. 9.6). The wind pressure is applied perpendicular to the wall surface to develop the design wind load. On the basis of AASHTO Guide Specifications for Structural Design of Sound Barriers, the pressure may be calculated from

U. S. Customary units: P = 0.00256(1.3 V)2 Cfc (9.1a)

SI units: P = 0.613(1.3V)2 CdCc (9.1b)

where P = wind pressure, lb/ft2 (N/m2)

V = wind velocity, mi/h (m/s)

Cd = drag coefficient = 1.2 for noise walls

Cc = combined height, exposure, and location coefficient

The factor of 1.3 in Eq. (9.1) provides for wind gusts...

read more

Planking the Roof

Posted by on 25/ 11/ 15

We used the same spruce two-by-six tongue-and-groove boards for the roof deck (sunroom ceiling) as we used for the floor. The most difficult part was tearing up a couple of feet of the earth roof on the house, so that we could marry the new roof to the old. I was pleased that the new material — from Russia — was almost identical to the lumber Fd used in the original roof, which was from Quebec. So, once the rafters had been extended, and the old gutter and drip edge removed, Anna and I were able to install the roof deck very quickly indeed, about two days...

read more

PROJECT DEVELOPMENT STEPS

Posted by on 25/ 11/ 15

Preliminary Engineering. During the preliminary engineering step, the following actions should take place:

• Develop a basic noise abatement plan, and determine barrier height and location.

• Develop alternative methods of abatement such as walls, earth berms, berm-wall combinations, etc.

• Develop alternative locations for abatement facilities.

• Develop alternative material types such as concrete, timber, masonry, or steel.

• Develop a conceptual landscaping plan for each alternative.

• Develop cost estimates for alternatives.

• Develop a general environmental plan.

• Make preliminary arrangements for public informational meetings.

Items to be considered in selecting proposed alternatives include aesthetics, traffic safety, sight distance, drainage, maintenance, existing ...

read more

Cut-off Drains

Posted by on 25/ 11/ 15

Drains can be placed as a trench or fin at the toe of a cutting, between the cutting and the pavement construction (Fig. 13.23). These act to lower the water in the cutting both increasing the stability of the slope and also reducing the water arriving at, and the pore water pressure in, the foundation of the pavement. Typically these cut-off drains also perform the function of lateral pavement drains (see Section 13.4.1). However, they differ from lateral pavement drains because they are designed to collect water from both sides of the trench or fin.

In porous ground where water tables are high, or high rainfall is anticipated, the drain must be designed to carry relatively large, continuous flows unlike nor­mal lateral pavement sub-surface drains...

read more

Binder Content

Posted by on 25/ 11/ 15

A series of categories of minimum binder contents in SMA mixes, denoted Bmin, is detailed in the standard. However, maximum binder contents are not defined; therefore an appropriate category of Bmin should be matched with each SMA specification.

The categories given in the standard have been adopted for a reference density of an aggregate mix equal to 2.650 Mg/m3. For aggregate mixtures with other den­sities, the required lower limit of the binder content should be modified using the factor a

2.650 a =

Pa

image164

FIGURE 14.2 The position of boundary points of SMA 11S gradation envelopes according to EN 13108-5 and German final gradation limits for this mixture according to TL Asphalt- StB 07.
Binder Content

FIGURE 14...

read more