Blog Archives

Moisture Content Effect on Bearing Capacity – a Danish Study

Posted by on 22/ 11/ 15

Relationships between bearing capacity and moisture content were studied in the Danish Road Testing Machine (ALT-facility) (Krarup, 1995). A typical Danish pavement was built in the facility, and for almost one year the only condition that was changed was the level of the water table. No load was applied except for FWD – measurements. The layer stiffness moduli (E-values) of the pavement layers were calculated from FWD-measurements with the program ELMOD (Dynatest, 1989). Based on the test results, a relationship between E-value and suction, pore pressure and degree of saturation was established. Simple linear regression describes the

Slighty clayey sand – Noucelles

1. pd = 1.70 Mg/m3 : M = 111.1 + 0.119 s

R = 0.980, N = 11

2. pd = 1.62 Mg/m3 : M = 113.1 + 0.084 s

R = 0.971, N = 13

Silt...

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AN OVERVIEW OF BATHROOM FIXTURES

Posted by on 22/ 11/ 15

This short section provides an overview of what’s available and a few buzzwords to use when you visit a fixture showroom. Start your search on the Internet, where most major fixture and faucet makers show their wares and offer design and installation downloads. One of the most elegant and informative sites is www. kohler. com.

Lavatories (bathroom sinks) are available in a blizzard of colors, materials, and styles. Styles include pedestal sinks, wall-hung units (including corner sinks), and cabinet-mountedbcvaiories. Wall-hung lavs use space and budgets economi­cally, but their pipes are exposed, and there’s no place to store supplies underneath. Pedestal sinks are typically screwed to wall framing and sup­ported by a pedestal that hides the drainpipes...

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GREEN FRAMING

Posted by on 22/ 11/ 15

Green Framing is as much an attitude as it is an act of doing certain forms of framing. There are some framing designs and materials that are considered “green" but to be a green framer it takes a belief that you want to be a part of the global effort to reduce our effects on the ecosystem. In this chapter I will show you how the green movement is affecting the materials we use and in some cases the way we frame. I will also give you a basic understanding of the construction industry efforts to become green. In additions to this, I will discuss some behaviors that if you so choose will make you a part of the movement.

A little history is probably a good place to start.

It’s hard to say when the first discussions about how the human race is effecting the environment occurred and what we c...

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Energy-Saving Tips

Posted by on 22/ 11/ 15

WHILE YOU’RE THINKING about insu­lation and ventilation, you should also pay attention to a few other details that relate to energy conservation. Taken together, these small improve­ments can make a big difference in how well your house works.

a Locate the water heater near the kitchen and bathroom. This avoids long runs of pipe that increase plumbing costs and dissipate heat between the water heater and the faucets or showerheads.

a In cold climates, keep water-supply lines out of exterior walls.

a. Use an insulated wrap for the water heater. Some water heaters come with built-in insulation. If yours doesn’t, buy a water heater insula­tion kit to reduce heat loss and con­serve energy.

a Insulate all hot-water lines, and insulate cold-water lines in a crawl space...

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Correlated-sampling techniques

Posted by on 22/ 11/ 15

Correlated-sampling techniques are especially effective for variance reduction when the primary objective of the simulation study is to evaluate small changes in system performance or to compare the difference in system performances between two specific designs (Rubinstein, 1981; Ang and Tang, 1984). Consider that one wishes to estimate

Подпись:Подпись: (6.81)A© = ©1 — ©2

in which

©1 = J g1(x) f 1(x) dx = E [ g1(X)] ©2 = / g2(y) f2(y) dy = E [ g2(Y)]

Подпись: A© = ©1 — ©2 Подпись: 1 n Подпись: Eg1( Xi) — E g2(Yi) . i = 1 i = 1 Correlated-sampling techniques Подпись: (6.82)

with f 1(x) and f 2(y) being two different PDFs. By Monte Carlo simulation, A© can be estimated as

in which Xi andYi are random samples generated from f 1(x) and f2(y), re­spectively, and A©i = g1(Xi) — gjjYi).

The variance associated with A© is

Var(A©) = Var(©©1) + Var(©2) — 2Cov(©b ©2) (6.83)

In the case that random variates...

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RUTTING RESISTANCE

Posted by on 22/ 11/ 15

Resistance to permanent deformation is the best known and most recognizable fea­ture of courses made from SMA mixtures. This resistance has its origins in the very strong skeleton of coarse particles of an aggregate mix. This issue was already thor­oughly deliberated in Chapters 2, 3, and 6, therefore only some additional informa­tion about testing that feature is provided below.

TABLE 12.1

A Comparison of Essential Functional Properties of Some Popular Asphalt Mixtures for Wearing courses

preferred

Functional

Required Fundamental mix

Typical values of various surfacing Types 0/13 mm size

properties

properties

oca

UTFC

SMA

cca

High skid

High surface

2-3 mm

1.5-3 mm

1-2 mm

0.2-0.5

resistance

texture

High

18-25%

12-20%

0%

mm

0%

interco...

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Meeting My Role Model on a Habitat Build

Posted by on 22/ 11/ 15

Подпись: THE FIRST TIME I remember working with Helen Sanders was when we were patching a rotten roof on a Habitat rehab in Charlotte, North Carolina, in 1992.1 was up on theПодпись: PHILIPPINES

roof, cutting out rotten sheathing with a circular saw, reaching as far as I could, with my foot supported by Helen, whom I’d just met. Just as I was stretched to my limit, depending totally on her for support, Helen said, “You know, my friends say a 72-year-old woman doesn’t have any business being up on a roof.” I fin­ished cutting out the rotten section of roof, but she had shaken my world: T thought she was 50.

Since then, Helen and I have become best friends. It has been nine years since we were up on that roof. We have traveled with Habitat to Africa, participated in several of Jimmy Carter’s Habitat projects, and worked hundreds of days together for our local affiliate. Helen continues to
work every Thursday in the field, moving at a steady, even pace...

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Antithetic-variates technique

Posted by on 22/ 11/ 15

The antithetic-variates technique (Hammersley and Morton, 1956) achieves the variance-reduction goal by attempting to generate random variates that would induce a negative correlation for the quantity of interest between separate sim­ulation runs. Consider that Gq and ©2 are two unbiased estimators of an un­known quantity в to be estimated. The two estimators can be combined together to form another estimator as

Подпись: (6.75)1

G a = 2(®1 + ®2)

The new estimator Ga also is unbiased and has a variance as

Var(©a) = 1 [Var(©1) + Var(©2) + 2Cov(©b ©2)] 4

If the two estimators ©1 and ©2 were computed by Monte Carlo simulation through generating two independent, sets of random variates, they would be independent, and the variance for ©a would be

Var(© a) = 1[Var(©i) + Var©)] (6.77)

4

From Eq...

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CREATING BATHROOMS THAT WORK

Posted by on 22/ 11/ 15

image679Подпись: The understated beauty of nature continues in this cabinet's soft, beveled edges and muted finishes. Slip- matched “ropey" cherry doors and drawers are edged with solid wood. Note the fine-grained “absolute black" granite countertop and matte black metal pulls.

Here are 12 factors that help make a bathroom comfortable, functional, and easier to clean:

► Enough room to use fixtures. Bathroom space isn’t efficient if there’s not enough room to use the fixtures easily and safely. "Bath Fixture Clearances," on p. 324, shows mini – mums, which may be superseded by local building codes.

► Keep it secure and intimate. Although shared bathrooms should be accessible to the rooms they serve, bathroom users should feel secure once inside. Avoid multiple-door accesses. Keep the room’s scale intimate as well: Warm, cozy spaces are best.

► Put private fixtures far from the door.

The most-used and least private fixture, the lavatory, should be nearest the door, so people can pop in and wash their hands quickly...

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Choosing a Range Hood

Posted by on 22/ 11/ 15

Cooktops and stoves should be vented by a range hood. In addition to sucking up the smoke of a charred steak, range hoods exhaust airborne grease that might other­wise migrate to a cool corner and feed mold or adhere to woodwork and discolor its finish, as shown in the photos on p. 454.

Range hoods are most often wall-mounted directly over a range. Alternatively, there are downdraft and side-draft vents that pop up from a counter area to suck away fumes. Over island and peninsula ranges, you can install chimney-type vents. In gen­eral, install the type of vent that will carry exhaust gases outdoors with the shortest and straightest duct run possible...

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