Relax wrote:penny wrote: 95% aggregate would produce some of the weakest concrete you can make. No room for binding agents.
FYI, as an engineering student you are exposed to that course, Strength of Materials - or its nickname just strength - in your lower junior year. 3rd year of a five year course. You had to do a year abroad.
But you've certainly reminded me why I needed a very long break from the forum.
Oooo instead of 95% it is 90% and if we are talking UHPC... 80%... yea this makes things so much "better"
Great a 10kWh battery now ***only*** requires 225 Cubic Meters under perfect conditions assuming making it does not destroy the material properties of the UHPC(yea right)... Lovely. Or, you can build a 10kWh battery in less than half a cubic meter... which actually has battery leads, is contained, protected, can be replaced.
Yes, you certainly reminded me why
PS: Strength of materials comes before Mechanics and is Freshman year or Sophmore year(latest if you take 1yr of community college) if you go to an engineering school. I do not know about general education Uni's. Your school did not start actual engineering courses until Junior year? Yikes! What was your horrific drop out rate? 95%? No wonder USA public Uni's are graduating fewer engineering students if you start actual REAL course work only after 2 years of garbage classes sucking you dry of $$$.
PPS Hrmm now my kid really did go to sleep... Uggg work tomorrow. Sorry if I am being short with you.
Interesting course study at your school.
In my day at my uni, Strength and Mechanics were taken concurrently. They were not prerequisites. Not in my day. Dunno about now.
And yes, actual engineering courses (at the university) were not offered until your (if you had bothered to read it)
lower junior year. Which is technically your second year if you scale it against other
four year universities. Again, it is a 5-yr course! At my uni.
Four year universities offer a well-rounded education. I was able to take cosmology as an elective. Loved that course! I admit that the four year uni forced electives on you. Again, a well rounded education. I am thankful. Especially when discussing just about anything with most two-year "college" students. As is my experience. But I digress.
As I said, my school forced you to take a year abroad as an exchange student. The standing joke at my uni at the time was "Your parents send you off to college, then the college sends you off to college." It was encouraged to study abroad your Sophomore year. The thinking at the time was nobody wanted to study abroad in the middle of advanced studies. But a student could certainly choose to study abroad the Upper Junior year; I think it is like that now.
As an exchange student you were in class at night and on the job during the day! Grueling! But lots of fun. And very exciting! A very tailored program! And that is Sophomore year and you are taking course studies. But not at your own university. But you could technically postpone the courses until you return. I didn't. I graduated a year early.
Freshman year was reserved for a solid foundation in the maths, chemistry and physics. Students pouring in from all over the county were leaving high schools that didn't even offer subjects like trig, geometry and physics. So your freshman year was building a solid foundation in those studies. I took theory in high school. Advanced chemistry. Advanced Biology. Calculus. Trig. Geometry. I was fortunate. Many students were not.
Sophomore year was spent abroad (if you so chose, and it was recommended). I was actually making fifty grand as an exchange student for an engineering company. As an exchange student? Boy did I learn a lot!!! And the pay was good. I didn't need the money at the time, but it looked good on my resume later. Try explaining to companies why you listed a $50,000 salary while you were in college! LOL
My third year, my lower junior year is when the shit hit the fan. Strength and Mechanics were offered simultaneously! They were back to back classes. Although a student could postpone mechanics until the following year. Your OJT as an exchange student prepared you for the courses. 18 credit hrs per semester was the lowest credits one could take. As opposed to 16 at the time for most universities. And whereas Tuesdays and Thursdays were lazy days at most universities, you were in school all day six days a week at my university. SCHOOL ON SATURDAY??? WHAT THE FUCK!!!
Saturdays was pretty much lab all day long! Engineering students actually had a passcode to get in the engineering building 24/7. And you needed it. It was the first time I was exposed to an environment like Hephaestus. The equipment and lab rivaled Bolthole.
Dropout rate? I am not sure about that. Except for chemistry. Chemistry at my Uni was a bitch at the time. I recalled students crying. And, yes, the dropout rate in chemistry was high at my uni. Students simply took it at the neighboring university.
But I do know about the recruitment rate. Engineering companies across the country, and especially locally, heavily recruited students from my university. A lot of universities teach you engineering without actually preparing you for the market. Engineering firms want to hire people who can hit the ground running without having to hold their hand. In fact, students from my uni were recruited too soon. The university had to encourage students not to leave study. Companies were hiring students before they even graduated. Summer jobs turned into full time careers. After a year abroad actually working in your field, you knew what you were doing already enough to accept a (sic) entry level position, for whatever reason.
After I graduated, I was immediately offered the position of Lab Manager. Six figure base salary right out of college. And this was the late seventies!
My first day on the job, there was an orientation waiting for me. The company made you feel at home. It felt like a surprise birthday party. I knew almost every single person there. Several had graduated from my university years before I did. We had met in the labs. I was astounded that the largest engineering firm in the country recruited almost exclusively from my university.
I later left the company and moved to California seeking to sow some wild oats and pursue a masters on a beautiful campus by the water. I was immediately hired as Lab Manager with a local company without an interview.
"You graduated from that program huh?" My new boss asked, rhetorically. That's a fucking grueling program. But you people know your shit!"
Women from my university were hired instead of men from other programs. I am still not over that. I am not a chauvinist, people. And I am happy the market was fair to women graduating from my uni. I was simply surprised by the fact, considering the era. But applicants from other programs screamed bloody murder!
Do note that concrete, as the article suggests has varying mixtures of aggregate. You don't want the strongest concrete for roads. Some poor schmuck will beat himself to death jackhammering that stuff just trying to get to a six inch water main that has burst. You have to be practical with your applications. Those roads will develop potholes easily. But they are practical. They are not airports where the runway must not develop potholes.
The strongest mix will certainly be used in powerplants. But if the plant suffers a catastrophe, the strongest concrete is going to be a godsend in one sense, and a bitch in another. Watching the documentary on Chernobyl, my heart went out to the heroes trying to wrestle with that concrete to contain the disaster.
But I've seen concrete in mixtures 20-30 % aggregate for special projects where strength was not needed. But simply the look and feel of concrete. Low strength concrete often replaces drywall.
At any rate, you still need to drop that 90% down a little further. 87-89 is the sweet spot depending on climate and application. In the real world!
As the thread suggests, varying strengths of concrete will be used for varying applications. I am excited.
For clarity, you still disagree with the proper usage of jibe and/or gibe as opposed to jive?
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The artist formerly known as cthia.
Now I can talk in the third person.
, it is ok according to them to bastardize, one word, jibe(sailing term) which most certainly never used to be used as "to agree with", but not the other, jive even though that word is most used in society and actually means to dance with the music which aligns with "to agree with" unlike jibe or gibe? 
It fueled good discussion. I do not want someone to agree with me for the sake of. That's no fun. Neither is disagreement for the sake of. But I will never be able to stomach blatant disrespect.