graduateprogram

March Metal Madness

Live from behind welding masks and safety gear, it’s the Thermal Mass and Buoyancy Ventilation Research Project Team!

Jeff watching Rowe weld

First, the team is mega grateful for the donation of material, work space, time and patience from Jim Turnipseed, head of Turnipseed International. He’s invited the graduate students to fabricate the steel for the stair, walkway, door frame, and most importantly structural columns and bracing for the TMBV Test Buildings at his metal shop in Columbiana, AL. Turnipseed International employees Flo and Luis are teaching the team how to weld, cut, and drill steel. They, as well as Javier, have been keeping the students safe and teaching them a ton! Thank you to Jim, Flo, Luis, Javier and everyone at the Turnipseed International for their guidance and generosity!

Practice makes… not so bad!

To start out their first week at the shop, the team practiced welding. They salvaged metal scraps and ground the surfaces and edges to help the welds bind.

Flo taught them how to work the MIG (Metal Inert Gas) welding machine safely. MIG is a welding process in which an electric arc forms between a consumable MIG wire electrode and the workpiece metal, which heats the workpiece metal, causing them to fuse.

After the team got the general motion of welding down, they began practicing more specific welds. This included welding perpendicular steel pieces, steel tube to plate and fusing square metal tube cut at 45-degree angles. These welds are similar to those on the walkway, stairs, columns, and handrails. Seen above is their pile of practice. At this point, there is no clear welding champion…

Grateful for Grate!

Next, the students knocked out the metal grating for the stairs and walkway which connects the Test Buildings to the ground and each other.

The students marked out the 3’ x 3’ 6” sections on the 20’ long 1” deep metal grating. Then they used the infant-sized angle grinder to break down the price where marked. The team got all the metal grating cut in one day!

Column Connections

In order to fabricate the steel columns and bracings which support the Test Buildings, the team had to prep all the pieces and parts. This meant drilling just under 100 holes for bolt connections in the steel plate and angle which make up the ground connections, bracing, and column base and top plates. The team was also deemed ready to weld the bracing ground connections seen above.

Next, the team beveled the column ends with a grinder to help them fuse to the top and bottom plates. They also marked the columns where the bracing connections were to be welded on.

In order to weld the bracing connections on plumb and level, the team rigged up a jig. They put their newly acquired welding skill to the test to make a stencil which held the columns and plate in place as they weld. They welded all the column connectors and will be moving on to top and base plates next!

students in the corner of Turnipseed international metal working shop

Above is the Thermal Mass and Buoyancy Ventilation teams’ home away from home. Tucked into the corner of the shop they have plenty of room and help from the crew to crank out the rest of their steel work. Thanks again Turnipseed International, and as always stay tuned!

Those pour, pour foundations!

Live from on top freshly poured foundations, it’s the Thermal Mass and Buoyancy Ventilation Research Project Team! This week the students, with a little help from their friends, completed their Test Building foundations. This included installing rebar and pouring concrete. Let’s get straight to those action shots, huh?

Rebar Retreat

First, Livia’s all time favorite activity, the cutting of the rebar. The team cut sections of rebar for the bottom rebar mat, the top rebar mat, and the vertical pieces that hold the two together.

Next, it’s install time. Comprised of number 5 rebar, the bottom mat is a regular grid. The north-south and east-west pieces are joined with rebar ties. The vertical pieces were hammered into the ground at a consistent elevation. This elevation is 1” lower than the future slab surface. These vertical pieces support the top mat, comprised of number 4 rebar. The top mat only runs between future column locations.

With the rebar installation completed, the TMBV team prepared for the concrete pour. Rowe built bridges to span the foundation excavation holes. The bridges will be used to shovel and trowel the concrete in the middle of the foundations. Jeff helped test bridge durability. Livia prepped her waterproof suit, she’s quite messy and will need to be hosed down with the shovels at the end of the day. Cory practiced his elevation calling as the master of the transit.

The Big Pour

If you find yourself wondering, why do these cute, little buildings need such an intricate foundation? Well, while the volumetric form of the Test Buildings appear small, they are actually quite monumental. Reaching 25’ tall and lifted 7′ 6″ off the ground, the test buildings experience substantial overturning forces which are counteracted by the foundations.

“We get by with a little help from our friends!”

With shovel-armed 5th-years, Steve long calling shots, and Andrew Freear on the chute, the pouring began. Everyone helped move the concrete around the excavation hole until it was about level with the grade pins. Grade pins are orange-painted, vertical pieces that are set to 1/4″ under the slab surface height. When the concrete reaches the grade pins evenly, Rowe and Cory began taking elevation measurements.

In order to deem the elevation, “Good!” the students meticulously move and smooth the concrete. Next, troweling begins once several spot measurements meet the elevation mark. While Livia and Jeff began finishing the surface of the west foundation, the others moved on to the east foundation. Pour, level, rinse, repeat! It is actually a good idea to rinse your shovel in between uses it isn’t ruined by the concrete…

Like most concrete pours, the fashionable ones at least, the TMBV ordered 10% extra concrete. However, the concrete suppliers do not typically take back the extra if it isn’t used. Because all that concrete has got to go somewhere, the TMBV team built formworks that match the size of the concrete scrap they already have. Therefore, they will have plentiful pieces for the design of their Cooling Porch. In the meantime, the mini-slab acts as an executive parking spot for Andrew Freear’s sky-blue Honda FIT.

The Finished Products

Completed east and west foundations
Reserved for Andrew Freear (spikes to be installed later)

Would you look at that—two beautiful foundations ready for curing. And an extra mini slab! The TMBV team could not have completed this feat without the help from the 5th-year students and faculty. The pour went smoothly with no catastrophic events! Next up, construction-wise, the team will install drainage and the steel structure. As always, thanks for stopping by and stay tuned!

f i n

Be Groovy or Leave, Concrete!

“Either be groovy or leave, man!” – Bob Dylan

The TMBV team attempts a vertical concrete panel pour

Live from Neck Down week, it’s the Thermal Mass and Buoyancy Ventilation Research Project team! From 8:00 AM to 3:00 PM last week, the 3rd-years, 5th-years, and graduates students have bonded over manual labor and project maintenance. This is the age-old tradition of Neck Down week, the start of each semester in which all year levels put their projects aside to spruce up Rural Studio’s campus and help out at ongoing and completed projects. The TMBVRP team snuck in some more concrete panel test pours in the after hours. Let’s see how they did it!

Panel Proposals

Before we dive into construction, it’s important to highlight what is different about these concrete panels. In contrast to the team’s last test pours these panels are smaller with tongue and groove edges. We will dive deeper into the tongues and grooves later. As seen above in the unfolded wall elevations above, the team experimented with different sizes and arrangements of panels. The main difference in the schemes where whether the running bond pattern stacked vertically or horizontally. The teams chose to test pour the more rectangular panels from both the vertical and horizontal running bond options.

Panel Preparations

For both chosen designs, the team planned to test making the most commonly recurring panel and the trickiest panel. Therefore, for each option the forwork for a typical rectangular panel and the more triangular panel, created by the sloping roof, was designed. However, a certain, not-Livia team member created the “construction” drawings seen above months before actual construction. The team has made significant leaps and bounds in construction drawing etiquette since. There was also much to the tongue and groove formwork that had not been fully fleshed out. So, as seen in the marked-up construction drawing above, much was decided on the fly. It was a very design-build experience.

Next, the team used their new tongue and groove router bits. Tongue and groove is a system of joining adjacent panels by means of interlocking ridges and grooves down their sides. Seen above are the first tests of the router bits to create the tongue edges for the panel formwork. For the formwork, the tongues and grooves were routed out of PVC board. PVC board will not chemically bond with the poured concrete, therefore, creating a successful cast. Connecting the concrete panels to one another using the joining system will improve their strength. The panels will act more as one structurally, but also thermally making a more effective thermal mass.

Horizontal Panel Pour

Along with testing the tongue and grooved edges, the team attempted two different pouring strategies; horizontal and vertical. Seen below is the typical, horizontal panel pour method. The team is pretty well-versed in this recipe. After pouring the panels, the team will let them cure for about a week. Onwards to the vertical pour!

Vertical Panel Pour

The vertical concrete formwork meant to create two perfect panel faces and ease panel transportation. However, you guessed it, the vertical pour was quite difficult. First, vertical formwork requires more pieces that need to fit together more precisely. You are in a sense making a very precise sandwich that leaks Mayonaise everywhere if you don’t get it right. Second, getting the masonry anchors to stay in place and attach through both large faces required a special bolting jig. Another new piece to make. Third, to keep the formwork upright required leveling and sawhorse structure. Fourth and finally, the team built a funnel to transfer the concrete through the 1-1/8″ formwork opening. And repeat for 60 plus panels!

While the smaller, triangular vertical pour went fine enough, the large rectangular panel busted open. As you can see above the triangular panel had little leakage out of the masonry anchor attachment areas. The rectangular panel however suffered catastrophic failures in this area. For now, the team awaits the curing process to see the results. However, based on these vertical tests they aren’t sure the reward will be worth the hassle. But, hey, where else in the world do you get to test pouring concrete panels vertically than in the Rural Studio graduate program? It’s always worth the hassle.

The Wood Rack

Last, but far from least, the team can’t wait to show off their new wood racks. Because the Fabrication Pavilion is their construction headquarters, the team was in charge of cleaning it up as a Neck Down week task. They are stupidly proud of these wood racks they built to take all their lumber vertical and clear space for more activities! Please admire them!

Copper has joined to say thanks for tuning in! Stop by next week to see how the panel pours and tongue and grooving worked out for the Thermal Mass and Buoyancy Ventilation Research Project Team!

The 100-Year-Home

Since returning from spring break we have been quarantining here in Greensboro and working on our project documentation to pass off to the next generation of Rural Studio students who will pick up where we left off and continue the work of designing and building affordable homes for the rural south. In addition to the technical documentation drawings, we put together documentation summarizing the ideals of our project and the thinking behind the design decisions:

The “100-Year Home” is a model for housing affordability in rural areas of the Southeastern United States.  The design’s goal is to create a durable, buildable, and efficient home within a tight budget. The home provides a framework for expansion and adaptation over time, allowing the home to be modified by its occupants as their family’s needs change and as the home is passed down through generations – becoming a vehicle for wealth creation. 

The home is designed in response to the specific conditions of the rural Southeast. This region is heavily impoverished, with limited access to resources or means for economic mobility. Due to the area’s economic, cultural, and geographical conditions, residents tend to form “kinship clusters” whereby members of an extended family live in close proximity, either in a series of small structures, or by adding to a home over time. This additive strategy results in sprawling homes, occupied by a large extended family that allows the family to share resources and live within a tight-knit support network. The major issue with these expanding homes is that to expand upon an existing structure (typically with a pitched roof and raised floor) the family must tie into the existing floor and roof structure. These connection points prove problematic over time as water penetrates the structure and begins to deteriorate the home from the inside. 

Our goal with this project is to provide a framework for this type of incremental expansion and adaptation over time as the family grows and changes. The strategy is straightforward: we provide a big, independently supported roof and a big slab with a simple one-bedroom home underneath. As the needs of the family change, the partitions underneath the roof can be added and subtracted at will without compromising the water-tightness or structural integrity of the building. 

Calibrate and Graduate

Team is posing with their new outfit

Exciting things have been happening at HomeLab lately! First, the Thermal Mass and Buoyancy Ventilation Research Project (TMBVRP) Team were able to install airflow sensors into the Concrete Chimney Experiment. Second, the chimney has brought in some impressive data. And third, the TMBVRP team participated in an end of the semester presentation and round table discussion with their big sister team, the Mass Timber Breathing Wall Research Project, and a cast of professionals in the architecture and building science research field.

This week the team received their Sensirion differential pressure air flow sensors. The sensors record a difference in dynamic and static pressure which the team uses to calculate bulk flow. Bulk flow is the total airflow at the sensor location. The team installed two sensors into the Concrete Chimney Experiment, one at the bottom and one at the top, to measure updraft and downdraft ventilation created by the thermal mass.

Just to refresh your memory, updraft occurs during the night when the cool, night air is brought in the bottom ventilation opening, warmed by the thermal mass, and exhausted out the top. Downdraft occurs during the day, the warm, exterior air is drawn into the top ventilation opening, is cooled by offloading heat to the thermal mass,  and vents out the bottom.  Being able to measure the direction and amount of ventilation is critical to understand if the Concrete Chimney Experiment is performing as expected.

And the results are in, our initial measurements from the airflow sensors do show that during the day the chimney is operating in downdraft and during the night it operates in updraft. This gives us proof of concept, that thermal mass is able to alter the atmosphere inside the chimney so that it goes against the exterior environment.

graph showing airflow in the test chimney

The GreenTeg temperature sensors have also brought in proof of concept data, showing that the thermal mass is having a damping effect on the interior air. It is important that the temperatures of the thermal mass and interior air cycle with the daily swing in temperature so that heat is absorbed by the mass during the day and offloaded during the night. This shows that the internal thermal mass is effectively moderating the temperature in the chimney and causing continuous ventilation. We are continuing our testing to further calibrate the amount of ventilation to achieve the most efficient and effective heat transfer between the internal thermal mass and air.

Temperature signal graph comparison

To wrap up our undergraduate work, we had a roundtable presentation via Zoom to give an update on where our work is and share our exciting results with Auburn, our collaborators at McGill, and professionals in the architecture and building science research field.  This panel included Billie Faircloth, a partner and research director at the architecture firm Kieran Timberlake in Philadelphia, PA.  Second, we were joined by Jonathan Grinham, who is a Lecturer in Architecture and Research Associate at the Harvard University Graduate School of Design.  Last but not least, is Z Smith.  Z is a Principal and the Director of Sustainability & Performance at Eskew Dumez Ripple in New Orleans, LA.  

It was a privilege to be able to present and have a productive discussion with such esteemed professionals.  We gained valuable insight on how to best relay the work we are doing do both those in the research field and the common person. In addition, their backgrounds led to an intriguing discussion on how The Optimal Tuning Strategy could be implemented at the building scale. It was especially awesome to discuss the successful data the team recently got form the Concrete Chimney Experiment. Both the data and the discussion gave the Thermal Mass and Buoyancy Ventilation Research Project Team a boost of confidence and pride in their work. It not always easy for these architecture students to wrap their heads around the science, but the hard work paid off. Thank you to Rural Studio, Salmaan Craig, Kiel Moe, David Kennedy, and the reviewers for a positive end of the undergraduate phase of the Thermal Mass and Buoyancy Ventilation Research Project.

Final shout out to the incredible Mass Timber Breathing Wall Research Project Team. As they complete the paper on their research and graduate from the Master’s program they still had time to do something very sweet for their little sister team. They passed along their Rural Studio lab coats, crossing out their names and writing the names of the TMBVRP team members. Their work, dedication, and attitude could not be a better example for the TMBVRP team to emulate. From one research project team to the other, thank you for helping us whenever we needed and being the best big sister team imaginable. We hope to live up the legacy! Well, everyone, stay tuned (optimally tuned) this summer for the start of the graduate program at HomeLab.