Clean-Up

Today, project managers Jessica Wolfe and Andrew Brown went out to the site to clean it all up. They cut the formwork and broke up the last chunk of concrete, and disposed of it properly. Now that this is done, BSCI Construction Company hopes to receive our Certificat of Substantial Completion from the owners.

We would like to give a special thanks to Stewart Construction Company for donating concrete rakes and metal stakes. This helped enormously in our slab pour. We are very grateful for their contribution.

Concrete Cylinder Break

Alex Gandy & Jordan Littlepage filled the concrete test cylinders on the first pour day, April 10th, 2012. The cylinders were placed in a curing tank of water where they rested for 7 days until the first break. The next and final break will be at 14 days. The cylinder partially out of the water was the actual cylinder that Carmichael Construction Testing broke.

The Break Card below shows the date received and age of the break, the slump of the mixture prior to adding water on site, the psi of the concrete made, and what the concrete was used for.

The concrete cylinder took 4,754 psi to break the cylinder into a type three break. This is the most common break with the type of concrete we used.







Cutting the Control Joints

Today, we cut the control joints in the slab. Cutting the control joints was not as hard as some might have suspected. The blade went through the concrete fairly easily; we just had to take our time and not try to force the blade through the concrete, but rather let the blade do the work. We cut each part of the slab 24 hours after the concrete was placed. We measured for our lines and then used a chalk line on make a straight line and then set our blade to be 1 inch deep in the slab and utilized a laser on the saw to stay on the line. The biggest problem that we encountered was that since the surface is not truly level in spots, we would hit small little bumps or small rocks that would throw us slightly off line if we were not careful. 

We cut 170 feet total and went through three blades. It helped to change out the blades when they started wearing down; once the blade starting wearing down, it made it very difficult to get a clean cut. The first blade we used cost $30 and lasted about twice as long as the one that cost $15. In cutting the control joints, we learned that you get what you pay for out of a blade. Both were comparable as far as cost and performance goes; it just depends on if you want to buy several blades or just one blade. 

Update: April 11th

Today we finished pouring the center strip of the slab. It went pretty smoothly after getting some practice from the first pour. The center strip did prove to be difficult due to its position, and we had to take precautions to keep from staining and scarring the other two previously poured sections.We also sprayed the cure and seal compound on the origional pour sections. Later that evening, several of us went back to cut the control joints in the outer two sections from the first pour. We cut the joints using a skill saw with a diamond blade.

Tomorrow, April 12th, we will go back out to finish cutting the rest of the control joints in the middle section.

Suggestions from President Williams

Today President Williams gave us suggestions about pouring the middle concrete slab section:

Update: April 10th

Tuesday was day one of the concrete pour. The concrete truck arrived at 2:00, and we finished pouring the first section at 2:45. We then called for the second truck, and poured the next section at 3:15. The concrete truck driver was extremely easy to work with, and gave us pointers on how to be more efficient with screeding the concrete.

Delivery ticket from concrete company.

The entire day went smoothly, and each student had an opportunity to do every job involved in the pour; this included screeding, floating, troweling, brooming, and edging. Superintendents Branden Reagin and Michael Stroecker did a wonderful job delegating the work and remaining composed under pressure. They helped teach those with less experience how to work with the concrete. It was a very successful day. We will be pouring our last section tomorrow, April 11th.

Update: April 8th

Today, we managed to get several people to come out and work, even though it is Easter Sunday. We were able to finish preparing the site for the pour. We needed to finish leveling the center section of our slab elevation and build the last two rebar cages above the ground as an experiment. We placed the rebar on top of some paint buckets we had laying around. Tying rebar closer to waist height improves efficiency and ergonomics. It worked well, and gave our backs a break since we weren't bending over the entire time. The real test will come when we move the cages into the formwork later this week.

Week 1 Wrap-Up

Site Status as of Friday, April 6th:

Substantial progress was made this week. Despite variable weather conditions, BSCI Construction Company managed to grade the site, build and place the formwork and keyways, and lay out the majority of the rebar cages.

Due to more thunderstorms, work yesterday and today was cancelled. We will reconvene on Sunday afternoon to finish up the two-rebar cages and the middle section of the sub grade.

We accomplished the goals we had set for the week. If things work out accordingly, our first pour day is scheduled for the afternoon of Tuesday, April 10^th. 

The site before work commenced on Monday, April 2nd. 

The site five days later, on Friday, April 6th.

Day 2

Day 2 commenced with a brief meeting with Steve Williams, our company president. He confirmed and approved the 50’ length of the slab diagonal, and helped us figure out the logistics for efficiently using as many people as we could on site.

The majority of the day was spent moving sand and dirt to bring the location of the slab to grade. After figuring out where the high spots and low spots were, we moved the sand with a shovel and wheelbarrow. Our goal was to avoid moving sand more than necessary; although we leveled the sub base, we still have about ½” to take off to satisfy the specified 4” slab.

Once the 3-10’ wide strips were screeded, we worked on the interior formwork. The key component for the interior formwork was the keyway. Superintendent Branden Reagin and his assistants glued and nailed the quarter rounds onto a 2x4 and then set them.

A main difficulty here was the fact that we lacked a drill to fasten the form-stakes to the forms. We had to attach 5-100’ extension cords together to bring power out to the site so that we could operate a corded drill. The team only got this line of forms completed today.

Overall, today was much more efficient than yesterday. We assigned each person to either grade the slab or help with the formwork; this allocation of jobs kept work running proficiently at all times. The only reason we did not get more done was the sudden afternoon thunderstorm.

 Weather permitting, we will continue this process tomorrow. We will also begin putting the rebar in the slab.

Breaking Ground: First Official Workday

Today was the first formal workday for the AU Outdoor Demo Lab. There were about ten students on site at different times throughout the day. We focused on building the perimeter formwork, stalking the boards in, using a string to make a consistent elevation, and splicing the boards when necessary.

First, we set the elevations at the corners with string lines.  Then, to build the perimeter formwork, we cut 2x4s into the correct lengths for each side of the exterior forms. The 40' sides were made of 3-12' boards, plus a 4'3" board on each side. The 30' sides were made of 10' boards; this will give the concrete truck ample room to be in the interior section on the day of the pour.

Pre-Construction Activities

Presentation to the Owners

March 23, 2012

Dry Cut Test

On Wednesday, March 28, graduate student Dan O'Hara built a form for two concrete samples. He then mixed a small batch of concrete and poured it into his forms.

After letting the concrete set for 12 hours, Terry Bryan did his first dry cut test using a circular saw with a diamond blade. The concrete was still fairly green, so the cut did not come out very smooth. After the concrete has had a full 24 hours to set, we will attempt another cut.

AU Demo Lab Assignment

Below is the original assignment sheet for the community service project in Professor Williams' Concrete Structures class.                                                                              

Preliminary Activities: We will be constructing a 30’ x 40’ concrete slab. The slab will is to 4 inches thick, and will be constructed on University property. As a part of your pre-construction services, the owner has requested a detailed Sketch-Up model showing (at a minimum) the following:

a) A basic layout drawing locating the slab in relation to pre-established points on property

b) A drawing of the slab superimposed on a photograph of the site

c) A detailed drawing of the formwork including exact material sizes and lengths, splice locations, splice details, steel stake locations, keyway details, form elevations, and location and depth of all control joints

d) A drawing showing the exact location of all reinforcing steel within the slab, including an accommodation for 2’ long splices, and specification of tie wire locations

e) A drawing showing the pour sequence, utilizing a concrete truck (drawn to scale) indicating the locations of the truck at various times of the pour

f) A drawing showing a complete material list, including all formwork, fasteners and concrete.

Groups: You will choose your own groups at the beginning of class on Monday, March 19. Groups will be comprised of 4 or 5 members. Each group shall designate a leader. Each group shall also choose one or two members that are charged with pre-construction services, who can immediately begin constructing the Sketch-Up model. Send (not later than noon on March 19) a listing of members ant titles to Professor Williams and Richard Allen.

Presentation of Pre-Construction Activities:

You will present your Sketch-Up drawings to the owners’ representative, Professor Bruce Smith, on Friday, March 23, in room 303 at 9:00 a.m. The presentation should last 20 minutes, and may include a 10 minute question and answer session.

Grading Criteria for Pre-Construction Presentation:

• 50% successful completion of all requirements
• 20% quality of drawings
• 20% quality of presentation
• 10% accuracy and completeness of material takeoff
• 10% extra credit possible

This grade for this presentation will be distributed equally to all students in the class, and will account for 20% of the entire grade for the project, so choose your group’s representative carefully.