Blog Archives

Interaction Between Percolating Water and the Pavement

Posted by on 11/ 11/ 15

In the road environment, contaminants are almost entirely moved by water-based or air-based processes. Air-based processes are, principally, by dust and spray, but these are not discussed further, being beyond the scope of this book. In water – based processes, contaminants are carried in and/or by the water through soil or aggregate pores, over the top of the pavement and through drainage systems. As water moves through the sub-surface, water that is fairly pure will have the abil­ity to pick-up chemicals from the soil through which is flowing and to carry these elsewhere while runoff water that arrives from the pavement surface may percolate into the construction carrying impurities with it which are then “dropped” by one mechanism or another into the layer...

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HOUSE AND LOT DESIGN

Posted by on 11/ 11/ 15

Factors which distinguish good design from poor design are somewhat subjective and vary from buyer to buyer, from builder to builder, and from architect to architect. There are certain qualities of good design that most can agree upon. These include a sense of comfort and good taste in the combination of materials, spaces, and equipment so that a feeling of inner satisfaction comes to the occupants of the home.

Good design and affordability are not incompatible. In fact, poor design at any price is difficult to market. The JVAH program proved that well-
designed small "affordable" homes actually enhance the neighborhood and add to property values.

Smaller lots present more of a challenge for placement of homes than do larger, more forgiving lots...

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LEAD-BASED PAINT REMOVAL

Posted by on 11/ 11/ 15

A significant number of state-maintained steel bridges are coated with lead-based paint. Steel bridges were coated with lead-based paint for more than 40 years. The coating sys­tems have an expected effective life of 15 to 25 years, and those on many bridges are now deteriorating. Life extension and overall protection of the bridges from corrosion are dependent on refurbishing deteriorating coatings.

The public has become increasingly aware that lead can represent a significant human health and environmental threat. When intact and in good condition, the paint does not pose a significant health risk. It is when paint is removed to prepare the surface for coating replacement, or as the paint deteriorates, that the risk of significant health risks escalates.

Many highway structures are loca...

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Mastic

Posted by on 11/ 11/ 15

Mastic is the second largest component of stone matrix asphalt (SMA); it is approxi­mately 20-25% by weight of the mixture and 30-35% by volume. About 35-40% (v/v) of the compacted coarse aggregates is made up of voids, and after filling the aggregate with mastic, 3% to 5% (v/v) of empty space will be left.

Mastic[9] consists of the following:

• Fine aggregate

• Filler

• Stabilizer (drainage inhibitor) in the form of fibers or other additives

• Bituminous binder

Filler and binder make up mortar. Blends of the fine fraction of the filler with binder act like binders and can be tested as a binder, but blends of the total filler and binder act more like a mixture and can be tested in that manner (e. g...

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INTERMEDIATE TO DIFFICULT

Posted by on 11/ 11/ 15

Framing and sheathing. These tasks are enjoy­able if you can swing a hammer accurately and work with someone more experienced to explain how to raise walls. If you use a power nailer to speed up the job, read the operation manual care­fully. Hard hats and eye protection are a must.

Hanging windows and doors. A well-framed rough opening (RO) makes the job a lot easier. You’ll need patience to plumb, level, and center the pre-cased unit in the RO, adjusting and readjusting shims till everything’s perfect.

Installing flooring. To get a good floor, make sure underlayment is level and solidly attached, measure and cut flooring carefully, and use appropriate fasteners or adhesives.

Plastering. This is difficult for the novice.

Plaster consistency and technique and the room’s temperature are al...

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COMMENTS ON THE PRESENTED METHODS

Posted by on 11/ 11/ 15

A downward trend that has been recently evident in Germany involves reducing the aggregate blend gradation discontinuity and establishing an upper limit on the coarse aggregate (bigger than 2 mm) content. These changes have been justified as ways to secure a more durable wearing course and to improve its compaction.

Although in some respects very appealing, another viewpoint on building a very strong SMA skeleton with coarse grains only is not without controversy. From a technological point of view and also from Dr. Zichner’s original principles, SMA is almost a gap-graded mixture. But are all gap-graded mixtures SMAs? Certainly not...

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Protecting Lumber from Decay

Posted by on 11/ 11/ 15

Moisture and warmth will promote decay of most woods. To prevent decay, naturally durable woods or preservative-treated wood must be used when the wood is exposed to moisture.

Decay-resistant woods include redwood, cedar, black locust, and black walnut. Preservative-treated wood is treated according to certain industrial specifications. Preservative-treated wood is most commonly used because of its availability.

Preservative-treated or naturally durable woods should be used in the following locations:

1. On concrete foundation walls that are less than 8" from exposed earth.

2. On concrete or masonry slabs that are in direct contact with earth.

3. Where wood is attached directly to the interior of exterior masonry or concrete walls below grade.

4...

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Design for the future

Posted by on 11/ 11/ 15

Consider building a wheelchair ramp leading to an entry or at least providing гост fora ramp to be built in the future. An accessible ramp has a 1 – in-12 rise (1 ft. of rise for every 12 ft. of length). When designing a house, its smart it) look beyond what your needs are today. Try to think about and allow for expansion in the future. An addition to the family—whether a new child or an elderly parent—often requires adding a bedroom. If you plan ahead, you 11 have room to expand when vou need to. This can save a lot of work and monev down the line.

Small doesn’t mean boring

Whether we admit it or not, we all respond emotionally to our surroundings. Buildings create interior environments that can be drab, distinctive, inspiring, or discouraging...

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Definition of an sma skeleton with other methods

Posted by on 11/ 11/ 15

In some countries (e. g., the United States and the Netherlands) a method of con­structing an SMA skeleton has been developed based on the control of stone-to-stone contact or a real gradation discontinuity. Based on these methods, the definition of SMA is expanded to mean an asphalt mixture containing mastic stabilizer (drainage inhibitor) with a gap-graded aggregate blend and a very high content of coarse aggre­gates in which smaller grains are seated among the bigger ones, filling voids among them but not shoving them aside. Based on this definition of SMA, it is necessary to determine the level of gradation discontinuity at which active grains are not shoved aside by passive ones.

Let us look at Figure 2...

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Grading of Lumber: The Good, the Bad and the Ugly

Posted by on 11/ 11/ 15

Serious organic flaws such as large knots at the edge of a timber can greatly diminish both shear and bending strength. (I will explain the difference in Chapter 2, when the differentiation is more important.) Other defects are checks (shrinkage gaps), splits, and shake (separation of annual growth layers.) Shake weakens a timber considerably. This is where lumber grading becomes important. Trained lumber graders can certify a particular timber as being of a certain structural grade. However, the buyer must still be aware. At a meeting of sawyers I attended in December of 2002, an example was shown of a graded two-by-four stud purchased from a large building supplier. The grade stamp was clearly printed right on the stud...

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