In the determination of our final panel design specs, many tests need to be performed so as to optimize in terms of our concrete mix with regards to the ratio of cement to water and deterimine the required reinforcement. Below is the list of concrete samples created and what tests will be/are being performedin order to aid in our optimization:
The first concrete panel was poured March 2, 2012 as a basic run through of procedure.
On March 8, 2012, three 2-inch thick beams were poured for testing at MTC in Grand Rapids, MI. One beam, the control, is 100% concrete. The second beam is reinforced by bamboo. The third is reinforced with common 3/8" steel rebar. The purpose of these beams is to compare the benefits of bamboo versus steel rebar. On March 9, 2012, a second batch of three beams were poured. These consisted of one control, one with bagasse and a third with two layers of chicken wire mesh. A third batch of these beams were poured on March 16, 2012. One as a control, one with treated bamboo, and one with non-treated bamboo. The treatment consisted of applying a wood varnish with hopes of water proofing the bamboo to protect against expansion. The testing of these beams took place on March 27, 2012.
From the testing, it was found that rebar had yet to fail at nearly 5000lbs of pressure, while bamboo performed little better than plain concrete, which is in part due to the pre-test cracking caused by the expansion of the bamboo as it soaked up water from the concrete and water tub that the beams were placed in during curing. It was also found that bagasse not only does not provide any structual benefit, but instead weakens the concrete as it creates weak planes within the concrete that facilitate failure.
The chicken mesh beam, as can be seen in the above picture, does not increase the strength of the concrete, but it does prevent the concrete from shearing, which can be the difference between a family in Haiti getting out of their home uninjured and not.