Blog Archives

Number of roller passes

Posted by on 19/ 11/ 15

Usually six to nine roller passes are enough to compact an SMA mixture. Moreover, compaction should not cause squeezing of the mastic onto the surface. The number of passes with vibrations should be limited to the indispensable minimum (most frequently, three).

On many construction sites or at the start of a new SMA mixture, it is recom­mended that the effectiveness of rolling in relation to the number of passes and type of rollers be tested on a specified section. The increase in density with more rolling passes is monitored with, for example, a nuclear density gauge, and the number of passes to reach the desired density is determined.

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Gypsum Board

Posted by on 19/ 11/ 15

Gypsum board, also known as gypboard, Sheetrock, or drywall, is the most common form of interior wall sheathing in modern res­idential construction. It is considerably less expensive than plaster. The 4- by 8-foot sheets are attached to the studs, then taped, sealed, textured, and painted.

Gypsum board is composed of natural gyp­

sum sandwiched between two sheets of card­board made from recycled newsprint. This cardboard backing creates problems when water damage occurs because it is a nutrient that encourages mold growth. In his mold in­vestigation work, John Banta has seen many cases where mold has begun to grow less than 72 hours after water damage occurs...

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Determinations of Availability and Unavailability

Posted by on 19/ 11/ 15

5.4.1 Terminology

A repairable system experiences a repetition of the repair-to-failure and failure – to-repair processes during its service life. Hence the probability that a system is in an operating condition at any given time t for a repairable system is different from that for a nonrepairable system. The term availability A(t) generally is
used for repairable systems to indicate the probability that the system is in an operating condition at any given time t. It also can be interpreted as the percentage of time that the system is in an operating condition within a specified time period...

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Materials MORE SIDING OPTIONS

Posted by on 19/ 11/ 15

IN ADDITION TO VINYL SIDING, there are three more exterior finisies to consider if you’re inter­ested in affordability, low maintenance, and attrac­tive appearance:

Composite wood. These planks are made the same way as OSB sheathing panels, but they look like solid-wood clapboards or horizontal lap siding when installed. This siding comes with a factory-applied primer coat, and it needs to be painted after instal­lation. Composite-wood planks don’t split, crack, or warp like solid-wood siding does, but they may not be a wise choice in extremely wet climates.

Stucco. Two tyaes of stucco finishes can be applied to house exteriors. Lightweight acrylic-type stucco treatments are available for application over specially prepared foam insulation board...

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Water Influence on Bearing Capacity

Posted by on 19/ 11/ 15

and Pavement Performance: Field Observations

Robert Charlier[20], Pierre Hornych, Mate Srsen, Ake Hermansson, Gunnar Bjarnason, SigurSur Erlingsson and Primoz Pavsic

Abstract This chapter presents a mechanical behaviour study, i. e. the bearing capacity as a function of the moisture degree. The field point of view is expressed and the chapter summarises a number of observations on road behaviour, in relation to variations of moisture. First, the road structure is recalled with respect to the mechanical analysis point of view. Then some observations onfield under temperate climate, humid, are given. In a second step, the specific case of frost and thawing are discussed.

Keywords Bearing capacity ■ moisture level ■ field measurement ■ stiffness ■ rutting ■ thawing

8.1 Introduction

This chapt...

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WAREHOUSES, FOUNDRIES, AND SUCH

Posted by on 19/ 11/ 15

Warehouses, foundries, manufacturing buildings, and similar buildings have some special requirements. For example, a shower must be provided for each 15 people who may be exposed to excessive heat or to skin contamination with poisonous, infectious, or irritating material. When you look at the table in Figure 9.12 you will see a number of numbers at the topic headings. Refer back to Figure 9.2 for an understanding of the special notes. An example of such a note is number 14 in the list of Figure 9.2. It says that one lavatory must be supplied for every 15 people who may have exposure to skin contamina­tion with poisonous, infectious, or irritating materials. Refer all of the special notes before you begin figuring your fixture needs.

LIGHT MANUFACTURING

Buildings used for light manufactur...

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CHARACTERISTICS OF ROADSIDE BARRIERS

Posted by on 19/ 11/ 15

Depending on their deflection characteristics upon impact, roadside barriers can be classified as flexible, semirigid, or rigid. Table 6.2 lists the most widely used barriers in each classification. Details of most of these operational barriers are presented along with other available information in Figs. 6.13 through 6.22. The dynamic deflection listed is that observed during the standard test defined by NCHRP Report 350 for the test levels listed in Table 6.2 as defined in Art. 6.4. Other characteristics of the barriers are discussed below.

TABLE 6.1 Barrier Warrants for Nontraversable Terrain and Roadside Obstacles*f

Подпись: Bridge piers, abutments, and railing ends Boulders Culverts, pipes, headwalls Cut and fill slopes (smooth) Cut and fill slopes (rough) Ditches (parallel) Ditches (transverse) Embankment Retaining walls Sign and luminaire supports^ Traffic signal supports§ Trees Utility poles Permanent bodies of water Shielding generally required A judgment decision based on nature of fixed object and likelihood of impact A judgment decision based on size, shape, and location of obstacle...

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HAIR SHOPS

Posted by on 19/ 11/ 15

Hair shops, like beauty salons and barber shops are required to have a drink­ing fountain and a service or utility sink. Figure 9.11 shows the basic require­ments for fixtures in these types of buildings. it is worth noting that only one lavatory is required for each bathroom, regardless of the occupancy load. it is also possible that beauty shops and barber shops might be required to main­tain only one restroom for occupants.

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Подпись: PLUMBER’S AND PIPE FITTER’S CALCULATIONS MANUAL

Building or occupancy2

Occupant content2

Water closets3

Lavatories4

Bathtubs, showers and miscellaneous fixtures

Clubs, lounges, and

40 sq ft per

Persons (total)

Male

Female

Persons (total)

Male

Female

Comply with board of

restaurants with club

person

1-50

2

2

1-150

1

1

health requ...

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Some More About Doorframes and Posts

Posted by on 19/ 11/ 15

With a lot of natural building being done these days, cordwood, cob, or straw bale walls of 16 to 24 inches thick are not uncommon. Doorframes will have to be equally wide. Earth woods cordwood walls are all 16 inches (40.6 centimeters) thick, so I make my doorframes from two four-by-eight timbers, with their 4-inch
(ioi millimeter) dimensions butted together, forming, effectively, a 4-by-i6-inch door post. These vertical timbers can be fastened together with metal straps, as shown in Fig. 4.54.

Fastening such a doorframe to a concrete floor requires two pins, one for each of the four-by-eights, to stop the doorframe from rotating...

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ENGINEERED WOOD PRODUCTS

Posted by on 19/ 11/ 15

Engineered wood products have been around for years, particularly in the form of plywood, glu-lam beams, and metal-plate-connected wood trusses. I-joists are more recent, as are LVLs (laminated veneer lumber), PSLs (parallel strand lumber), and LSLs (laminated strand lumber).

It is not the intent of this chapter to explain everything there is to know about engineered wood products, but rather to make you familiar with this category of materials, and give you a sense of what to look out for when you are working with them.

Engineered wood products (EWP) fit into two general categories, engineered panel products (EPP) and engineered lumber products (ELP). The

first group includes plywood, oriented strand board (OSB), waferboard, and composite and structural particleboard.

The second group in...

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