Purdueenginerd

more common than you think! Even for small-ish pours. Refer to section 2.4 http://dl.mycivil.ir/dozanani/ACI/ACI 305R-99 Hot Weather Concreting_MyCivil.ir.pdf (older version)

Concrete curing procedures are based on ACI 308.1 (http://dl.mycivil.ir/dozanani/ACI/ACI 308.1-98 Standard Specification for Curing Concrete_MyCivil.ir.pdf) (link is for the 1998 version, I think the latest version is actually 13). Can't tell what they've put down from the photos but at least from 200' away they appear to be complying with section 2. A contractor, should follow curing procedures on all of their concrete placements. Outdoor Flat work pours are especially susceptible to damage if procedure isnt followed. The reason for performing these actions is because when concrete cures, the chemical reaction of water and cementitious materials puts off heat, ie, it is an exothermic reaction. A temperature differential between the interior and the exterior faces of the concrete can built up tensile stresses and cause large cracking in the face of the concrete (this is bad!) In addition, for flatwork and/or outside pours, air flow, evaporation, and sunlight can change the strength characteristics of exposed sections of the concrete(this is bad!). Curing procedures are put in place to make sure these bad things dont happen or are mitigated. IE, ensuring that exothermic concrete can dissipate heat more quickly, or alternatively, make the concrete uniformly warm. For Mass pours.. or concrete placements that are huge. Additional steps have to be taken to mitigate these affects. ACI207.1R-14 (http://dl.mycivil.ir/dozanani/ACI/ACI 207.1R-05 Guide to Mass Concrete_MyCivil.ir.pdf) (i've provided an older version). Provides guidelines and specifications on how to handle that. The history section of the commentary is quite educational if you'd like to learn more. There are additional specifications for Hot weather and Cold Weather concreting.

yeah, lots of earth work on this one. Agree with you Triton. Very large project for 358 units.

LOL.

A few years ago I had a repair project at petrochemical facility where we had a mass-pour with a high-early strength concrete. A 2' thick concrete roof deck for a below grade structure. After the concrete set (to give you context on how fast it was setting, I could walk on one side of the roof while the other side I would sink into), the contractor basically flooded the top of the concrete with 3 inches of water. The next morning, I recorded the water temperature at 120ºF. It was stunning to me how much energy it put out curing. The contractor indicated they had a fire break out several years back because of extreme exotherming of the setting concrete.

agreed. thats an awesome photo. The volume capacity of a concrete truck is about 10 cubic yards fully loaded. I'm counting about 25-28 trucks total lined up. Thats a lot of concrete.

The entire building is about 10k sq feet.

There are gonna be some sick neon lights for sure on this facade.

I know a few actually who do. I do collect old AISC steel construction manuals (though I use them for work still on occasion) Right now I have 1st, 5th, 6th, 7th, 8th, 9th, 13th, 14th, 15th edition. My 1st edition is dated January 1930. Found it for about 60 dollars online. The 5th, 6th, 7th, 8th, 9th I have found at Half-Price Books over the years, each for about 15-20 dollars. 13-15 Ive used in my professional career so I bought them when they were/are still active codes.

Yes! You want the concrete and rebar to act as a composite material. The rebar deformation patterns were standardized in 1947. Before then there was a lot of variance on rebar deformation patterns and a lot of proprietary shaping by manufacturers . Even older concrete structures (Normally pre-1920's) have "smooth" bar.

its 13 pounds per linear foot. Excellent paper weight material!

Fun Fact! #3 bar, Diameter 3/8" #4 bar, Diameter 4/8" #5 Bar, Diameter 5/8" #6 Bar, Diameter 6/8" #7 Bar, Diameter 7/8" #8 Bar, Diameter 8/8" #9 Bar, Diameter 9/8" (also 1 in^2 in cross area) - Pre 1940's, #9 bars would traditionally be square 1"x1" bars. #10 Bar, Diameter 1.27" (They stopped using the previous numerical system) #11 bar, Diameter 1.41" #14 bar, Diameter, 1.693" #18 bar, Diameter 2.257" Here's a picture of #18 bar I took the other day

Crane all the way up these morning.

This comes off as a little needlessly accusatory, FYI. Anyway, to settle the population density of Houston here's an interactive map, from 2014. https://www.arcgis.com/home/webmap/viewer.html?webmap=85a821d13a4f4502a85f71c4aae8bae8

I would consider midtown houston to be part of the city center. I know when I lived there I routinely used the light-rail to get to downtown and the med center. I would imagine a not-unsubstantial percentage of midtown residents commute to either downtown or the med center and contribute to the pedestrian traffic of both. If theres going to be signficant residential growth in the city center, Midtown and South Downtown are primed for the most growth, in my opinion.