Difference between Malleability and Ductility

“The difference between malleability and ductility is that malleability is the ability to deform easily upon the application of a compressive force, and ductility is doing the same with tensile force.

*Ductility is a mechanical property used to describe the extent to which materials can be deformed plastically without fracture.

In material science, ductility specifically refers to a material’s ability to deform under tensile stress; this is often characterized by the material’s ability to be stretched into a wire.

Malleability, a similar concept, refers to a material’s ability to deform under compressive stress; this is often characterized by the material’s ability to form a thin sheet by hammering or rolling. Ductility and malleability do not always correlate with each other; for instance, gold is both ductile and malleable, but lead is only malleable. ”

Source: http://answers.yahoo.com/question/index?qid=20090303051823AAFRJmT

Difference between Laitance & Efflorescence

Laitance and efflorescence are really two completely different things, but they are both white, powdery substances, which can be confusing.

In short, laitance is formed when there’s too much water in the concrete mix, while efflorescence is the deposit on masonry surfaces caused by soluble salts in the units or in the mortar.

Laitance can be avoided by controlling the amount of water in the concrete mix. Efflorescence can be prevented, or at least minimized, by selecting materials free of harmful salts and by preventing water from penetrating the masonry. This may be accomplished by the use of solid and tight mortar joints, capped walls, effective flashing, and adequate weather protection of the masonry during construction.

Both laitance and efflorescence can present both cosmetic AND structural problems.

read more:
http://en.wikipedia.org/wiki/Efflorescence
http://www.concreteconstruction.net/concrete-articles/meaning-of-laitance.aspx

 

 

Air Entrainment

Air-entraining agents is a type of admixture.

Air entrainment is the intentional creation of tiny air bubbles in concrete. The bubbles are introduced into the concrete by the addition to the mix of an air entraining agent, a surfactant (surface-active substance, a type of chemical that includes detergents). The air bubbles are created during mixing of the plastic (flowable, not hardened) concrete, and most of them survive to be part of the hardened concrete. The primary purpose of air entrainment is to increase the durability of the hardened concrete, especially in climates subject to freeze-thaw; the secondary purpose is to increase workability of the concrete while in a plastic state.

Source: http://en.wikipedia.org/wiki/Air_entrainment

Time Out

Origami Christmas Tree

“Architect’s Christmas Tree” made from architectural drawings

As the holiday season approaches, I decided to take a little break and have some fun. Every year I try to make something architecture-related by recycling some of the paper from work. This year I made an origami Christmas tree with some drawings. I call it “the architect’s christmas tree”. I like the sculptural yet structural quality of it. It’s not super easy, but it’s also very forgiving. The print on the paper gives it some texture and any imperfection just makes it more organic. You can of course also use any other paper- renderings, magazines, sheet music etc.

You can make your own by clicking on this link or watching this youtube video:

The one I made last year (in the background) can be found here.
Have a witty, classy and environmentally-friendly christmas. Enjoy!

The Day before the Exam

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I guess that’s something I developed from piano recitals and basketball games growing up… the day before THE DAY is always reserved for rest. The last 24 hours before an exam do matter a lot, because there’s so much to memorize that sometimes you just have to rely on your short-term memory. But then there’s so much pressure that I felt like I needed to relax a bit, otherwise I was just gonna crash. Luckily there’s this place King Pong right where I work… so on Wednesday, instead of going home to study right away after work, I went for an hour of “Indian vs Hong Kong” with my coworker Ankur. It was so much fun and so much stress relief. Totally worth it!

I took CDS yesterday, it went ok. Could I have done better if I spent that hour I spent on playing ping pong studying? Maybe, maybe not? We’ll see in a week.

ARE 4.0 Reading

Visualizing ARE 4.0 [Part 1] [ Part 2] [Part 3] [Part 4]

arewethereblog_ARE 4.0_reading

Click on image for full resolution pdf

The ARE seems to be such a mystery to a lot people. For those who are looking to get started, the two most asked questions are “What do they test you on?”, which I attempted to answer in my previous post, and “Is there a lot to study?”, which is what I try to answer in this post. Short answer, 1794 pages. Long answer…

I have made this diagram that visualizes how many pages there are to read in each test, from the two main publishers. Before we dive into the diagram above, I must make one point extremely clear:

Kaplan and Ballast are NOT the only books you have to read.

Kaplan and PPI (commonly referred to as “ballast”, after the author) are both publishers who publish ARE review materials. They seem to be the most popular, although I don’t know if NCARB has ever declared them “official” study materials. Some people study them exclusively while others say they are “complete waste of time”. If you go to “coach”‘s forum, you will see a diverse range of study materials and different opinions about these two publishers. Resources go from wikipedia, youtube to user-contributed notes, flash cards and quizzes, but that’s the topic for another post.

Nevertheless, Kaplan and Ballast are usually where people start. Kaplan publishes one book for each test and Ballast is one giant 800-page review manual. I broke them down to all the chapters so you can see the topics in each test. Since Ballast is one complete book, it does not repeat information if it’s included in two different exams, but only cross-references it between sections. Kaplan on the other hand, tends to repeat information in different books.

There are few things that this diagram doesn’t quite convey:

  1. Ballast is more technical and more wordy. For me it takes at least twice as long to read one page on Ballast compared to Kaplan.
  2. Some content areas are way heavier and more complicated than others. This is highly subjective, it really depends on your knowledge and work experience. Like for me, going through 10 pages of PPP’s “urban design” is like a walk in the park compared to 10 pages of SS’ “Seismic Design”. All I am trying to say is merely looking at the number of pages might not give you an idea of how hard the subject is.
  3. The “links” between tests are the most obvious ones, but there are many overlaps in general. You will know what I mean ones you start studying.
  4. These are pages for the multiple choice section only. You will also have to read and practice for the vignettes.

So here you go, my attempt to answer “how much do I have to read”. Not too surprisingly, SS is the winner, followed by CDS, BS, BDCS and PPP with more or less the same amount of reading, and then SPD has the least. The amount of time you have to spend on reading them depends on your test-taking order, familiarity with the subject matter and whether you focus solely on these two publishers or branch out to read materials from other sources.

Like I mentioned previously, getting started is the hardest thing to do. Once you get started, the more you read, the faster you read, and the more comprehensively you understand things. For me, the first 1-2 months were hell and everything got easier afterwards. I personally don’t like reading (architects are all visual people after all, right?), but I do have to say, there is so much I just can’t learn from work (nobody has time to explain to me how all different types of HVAC system works) and reading all the materials has helped me a lot professionally.

Again, please feel free to share this with whoever wants to know more about the ARE.

Now, back to my reading of the AIA contracts for my CDS test next Thursday…

Visualizing ARE 4.0 [Part 1] [ Part 2] [Part 3] [Part 4]

What Trumps What (CDS)

If any discrepancy exists…

1. Specifications trumps working drawings.

Updated: Apparently that is NOT true! Specifications and working drawings are complimentary to each other. If contractor notices discrepancy between the two, the first thing to do is to bring it to the architect’s attention. (source: ballast Q&A)

2. Working drawings trumps shop drawings.

3. Written word (e.g. four hundred and ten) trumps numerical figures (e.g. 410) in bid forms.

4. Owner/ Contractor Agreement trumps General Conditions.