Monday, June 18, 2012
Installing the cages takes a fair amount of time and for the Second Tier Bond Beam much of the fabrication had to be established in place. For this install the build team had additional help from Corey and Ethan who installed much of the cages with the help of the now seasoned cage fabricator, Chris. Corey and Ethan also poured the Second Tier Bond Beam.
The form work for the second tier bond beam is crafted in such a way that there are no yokes to impede the flatwork/finishing that has to take place to the top of the bond beam. It is poured as one continuous unit to eliminate any cold joints and for greater structural integrity. Much of the form work is built in place and supported to the structure below.
Saturday, June 16, 2012
SYSTEMS + TECHNOLOGIES
At the site of our school and water tower builds there are a variety of systems and technologies that are currently implemented and proposed for this year. These systems include: solar power, solar thermal, rural internet, bio-sand filter, and a fast sand filter which is diagrammed above. The basic sketch diagrams the staging of tanks that will be used to filter out the iron that is very present in all of the water that feeds the school and lodge. In addition to the tanks there will be two solar panels, a solar pump that drafts water from the well, and two float switches that will control water flow and timing. This system can be expanded to meet local needs of potable water with the addition of charcoal tanks which are used locally for drinking water at a near by ranch. For now the water tower and filtration system target the removal of iron from the well water. The new tower will also be taller than the last and in turn produce greater water pressure.
A system that would provide internet through cellular signal amplification was designed by e-magine at the University of Michigan specifically for rural and remote regions. The system includes a signal booster, modem with sim card, router, a directional antenna and arduino technology to respond to humidity. A viable internet connection has not yet been realized but through strategic testing we have targeted specific issues that will be tested out to pinpoint and resolve the problem. Currently we believe that we need either more height on the antenna or there may be a problem with our signal booster. There is also a general question of what signals can be amplified and if cellular and data signals are fundamentally different and if so, is there a viable signal close enough to be amplified.
This year a team of engineering students implemented a bio sand water filter at the site and at other schools in the area. This is the third year of research and implementation of this filtration system and this year the team seems to have come close to perfecting the system itself. The variable that remains is the question of how well and rigorously the filter will be maintained by the locals. The desire for clean potable water in the area would suggest the necessary incentive. Particularly when (like this year) the drinking water is brown, what the locals refer to as chocolate water.
Friday, June 15, 2012
In week four the delays piled up, our team became smaller, yet we managed to get a fair amount accomplished once the materials did arrive to the site. We poured a bond beam which was already formed, poured two slabs (one on grade and one as a ceiling), two retaining walls, poured the Second tier columns, and laid the brick foundation for the closet. We have begun to work long days (sometimes completing a pour before breakfast) due in part to losing a week because of delays. The weather continues to be extreme. Sometimes extremely hot and the mosquitoes continue to be crazy. This has become somewhat stressful but all in all the quality and work ethic of the 2012 build crew has shown, literally working through the madness to prevail and hammer out lots of work in week four.
(TOP) We decided to hitch a ride on the back of a materials truck to get from Pocone to the site (3.5 hour drive). The truck broke down and we spent 6 hours on the side of the road waiting for a mechanic and getting back on the road.
(BOT) The second load of material was sent on a truck that would get stuck at the site and therefore the drive had to dump the sand on top of the gravel. This was a problem and a fair amount of added labor to sort the sand and gravel.
While I install reinforcement for what is to be a cast in place concrete ceiling Alli and Chris fabricate the cages for the second tier bond beam. After pouring the Tier one bond be we removed the formwork which we will reuse for the third time to pour the Second tier columns. The bond beam looks great.
While we were waiting for the bond beam to cure to a more solid state the team worked on foundations and retaining walls that would allow us to stage filtration components at different elevations so gravity can move water from station to station. A foundation for the closet is also integrated into the larger system. Some pipes are installed in the foundation to allow for us to fish electrical wiring through for the solar pump and float switches which will be installed in a couple weeks.
In one bay of the water tower there will be an enclosed closet at the ground floor. We have installed a mix of #3 and 4.2 mm rebar as a mesh reinforcement. I have woven it together in an attempt to create what would be considered a welded wire mesh and have attached the mesh to the bond beam cages prior to pouring the bond beam. Here we are forming the slab to be poured.