Blog Archives

HANDSAWS

Posted by on 12/ 11/ 15

The following inexpensive handsaws are handy to have:

Coping saws cut curves into any thin stock, although their primary use is coping trim so intersecting pieces fit snugly. They take both metal – and wood-cutting blades.

A hacksaw is most often used to cut metal, espe­cially bolts or nails. Sawblades will last longer if you use the full length of the blade.

A Japanese saw cuts on the pull stroke. Its thin, flexible blade is perfect for cutting flush shims and other thin stock. Most are two-sided, with rip and crosscut teeth.

A handsaw is still worth having in your toolbox, preferably a 10-pt. crosscut saw. Even if you depend primarily on a circular saw, a handsaw is handy for finishing cuts that don’t go all the way through a rafter or joist.

A dovetail saw makes clean crosscuts in smal...

read more

STABILIZERS (DRAINAGE INHIBITORS)

Posted by on 12/ 11/ 15

In the 1960s—during the beginning stages of SMA manufacture—the need arose to incorporate stabilizing agents to prevent binder draindown. Such additives are called stabilizers; they stabilize or keep the binder in place. Because of these stablizers, an increase in the binder film thickness on the aggregate is possible.

The two main techniques of reducing binder draindown are as follows: [17]

Each of these methods will be discussed later in this chapter, but let us start with a definition of a stabilizer. A stabilizer or drainage inhibitor is an additive to an SMA asphalt mixture put in to prevent binder (or mastic) from draining-off. Stabilizers may be made up of various materials, including both binder absorbers (e. g., fibers) and viscosity boosters (e. g., polymers).

In addition to ...

read more

Agricultural Waste

Posted by on 12/ 11/ 15

Recycled agricultural waste has potential for use in many applications not related to high­ways. Uses of agricultural wastes (with a few notable exceptions) in highways are usu­ally restricted to landscaping applications. It is estimated that more than 2 billion tons (1.8 X 1012 kg) of agricultural waste is produced each year in the United States. This rep­resents about 46 percent of the total waste produced in the United States each year.

Animal Manure. Animal manure is produced at a rate of 1.6 billion tons (1.5 X 1012 kg) annually in the United States. Other than its use as fertilizer or as composting material for landscaping rights-of-way, it has little recycling value for highways.

Crop (Green) Waste...

read more

GRIPPING TOOLS

Posted by on 12/ 11/ 15

Mechanical hands are what carpenters call the many pliers, wrenches, and clamps we use on job sites. When we
can’t tighten a nut by hand, we use a wrench. What we can’t hold with our fingers, we hold with a pair of pliers. When we can’t bring together a glued-up tabletop with our hands, we use a clamp.

Wrenches

Most carpenters carry a wrench or two in their toolbucket. I carry three types: a crescent wrench, an Allen wrench, and a pipe wrench.

I use the crescent wrench the most. The business end has a jaw that can be adjusted to different sizes by rotating a knob near the handle. When using a crescent wrench, make sure it fits snug on the bolt head or nut. A loose-fitting

GRIPPING TOOLS

Many items in construction are held together with bolts, so a carpenter needs to carry a few wrenches in his to...

read more

The scope of the book

Posted by on 12/ 11/ 15

To provide a detailed reference, the scope of the book had to be limited. I decided to focus on the parts of a building that contribute most significantly to its lon­gevity. Virtually all the drawings, therefore, describe details relating to the structural shell or to the outer protective layers of the building. Plumbing, electrical, and mechanical systems are described only as they affect the foundation and framing of the building. Interior finishes and details are not covered because they are the subject of a companion volume, Graphic Guide to Interior Details (The Taunton Press, 1996). The process of construction, covered adequately in many references, has here been stripped away so as to expose the details themselves as much as possible...

read more

Mining Waste

Posted by on 12/ 11/ 15

Coal Refuse. Coarse coal refuse from mining operations is produced at a rate of 120 million tons (109 X 109 kg) per year. Coarse material is banked, while fine coal refuse is put into a silt-sized slurry mix and placed in impoundments. It is estimated that up to 4 billion tons (3.6 X 1012 kg) of coal mining refuse has accumulated in the United States. Concern about spontaneous combustion and leachate of the material (composed of slate and shale with sandstone and clay mixed in) has impeded in-depth studies of the use of coal waste. It is currently being evaluated for use in embankments and as subbase material, two applications that reportedly have been used in the past.

Quarry Wastes...

read more

The plain of lower Mesopotamia: irrigation, navigation, and river engineering from the Sumerian city-states to the Persian Empire

Posted by on 12/ 11/ 15

Irrigation practice in lower Mesopotamia

Field studies have shown that the urbanization of the Inrd millennium BC developed along watercourses, whether they were natural river branches or artificial canals. Notable among these studies are those of the American archaeologist Robert McAdams (Figure 2.3). However, it seems likely that at the time of the independent city-states, secondary irriga­tion canal systems remained essentially local, their layout dictated by the nature of the soil surrounding each city: a band of gardens here, a band of irrigated cereals there. Canals effectively define the boundaries between cities. And of course conflicts over the shared use of water arose along such boundaries...

read more

From Mesopotamia to the Syrian Shore: The land of the water pioneers

Posted by on 12/ 11/ 15

The triangle of land framed by the Tigris and Euphrates delta, Armenia, and the Syrian coast saw the development of the earliest large-scale techniques for water exploitation. From the IVth millennium BC through the conquest by Alexander the Great (in 331 AD), truly exceptional development occurred in this area.

The most important Sumerian city-states of lower Mesopotamia were Uruk and Larsa to the west; Umma, Lagash, and Girsu to the east; the large port of Ur to the south, and Nippur to the north. These cities imported wood and metals as raw material. The source was Bahrein (Dilmun) in the Persian Gulf, to which the following IIIrd millenni­um BC text attests :

”Ur Nanshe, the king of Lagash (…) dug a canal ( …) so that Nanshe could bring water into

the canal...

read more

Stabilizers (Drainage Inhibitors)

Posted by on 12/ 11/ 15

Stone mastic asphalt (SMA) mixtures require a high content of binder, which results in thick binder films on the aggregate grains. To avoid the draindown effect, stabi­lizing additives (drainage inhibitors) are indispensable in most cases. This chapter describes the types of stabilizers and methods of testing them.

4.1 THE DRAINDOWN EFFECT

Have you ever seen fat spots on an SMA surface? Or binder running out of a truck hauling a hot SMA mixture? If you have, those troubles may have been caused by a binder or mastic draindown.

An SMA asphalt mixture has an intentional binder surplus. The specific surface of the mineral mixture is too small in relation to the designed binder volume...

read more

Selection of a Binder

Posted by on 12/ 11/ 15

In countries where paving grade bitumens (unmodified) are used in SMA, it is usu­ally assumed that the application of hard binders to ensure improvement in rut resis­tance is not necessary. It is generally accepted that, ensuring rut resistance should be accomplished by creating the correct mineral skeleton. So medium-grade binders are justified for use in SMAs, such as the popular 50/70 binder used in Germany or the 70/100 used in the Netherlands. A very soft binder like a 160/220 may be seen in Europe (e. g., in Finland); in very cold climate conditions, use of such a soft binder in not surprising.

The selection of a binder for an SMA wearing course is determined, on the one hand, by the temperature range over which the pavement is expected to perform and, on the other, by the expected...

read more