In the past 3 months, Safuan, our architect intern from Arkitrek have been working on our long term plans for a more sustainable and environmental friendly /green building project at all of our Camps in Borneo by continuing work experiment on bio-crete brick mix on site apart from working on the final phases of the Community Centre at Camp Bongkud. At the final stage of his intership, this report is invaluable to us hoping we finally get the right mix of recipes realizing the bigger picture of it all. Safuan was assisted by Camp staff and volunteers during his time out here. Here is his report which narrates the progression of unfired bricks exploration and how it will advance in the futureÛ_ Objective of Experiment Camp Borneo is keen to have their own unique product of construction materials, in accordance with their theme and identity of exploring/conserving the nature and engaging with community. Meanwhile, Arkitrek aims to conserve natural resources through design. Popularising bio-crete will allow us to reduce or phase out the energy intensive, environmentally harmful and non-renewable quarrying for cement and mineral aggregates in favour of more responsible alternatives. åÊ What are we looking to find out from this experiment? Û¢ Most suitable ratio of ingredients to produce a bio crete brick using brick presser. Û¢ Method statement of the overall process, the tools used, the procedure undergone and the faults done. Û¢ Variety use of natural fibre in bio crete bricks and how it behaves as building material åÊ åÊDay 1-21/03/2013 I have laid out few types of natural fibre to be tested in this experiment. They are: åÊåÊåÊåÊåÊåÊåÊåÊåÊåÊåÊåÊåÊåÊåÊåÊåÊåÊåÊåÊåÊåÊåÊ Û¢ Coconut coir (separate experiment for both bigger chunk and finer fibre of the coir; in order to determine the best mix regarding their workability and strength) -fig 1 åÊåÊåÊåÊåÊåÊåÊåÊåÊåÊåÊåÊåÊåÊåÊåÊåÊåÊåÊåÊåÊåÊåÊ Û¢ Rice Husk (to compare the compressibility of the fibre with coco coir) åÊåÊåÊåÊåÊåÊåÊåÊåÊåÊåÊåÊåÊåÊåÊåÊåÊåÊåÊåÊåÊåÊåÊ Û¢ Straw paddy ( only available after the harvesting period on April) åÊåÊåÊåÊåÊåÊåÊåÊåÊåÊåÊåÊåÊåÊåÊåÊåÊåÊåÊåÊåÊåÊåÊ Û¢ Betel Nut ( One of the villages proposed the fibre of betel nuts when they saw me working on the coconut coir) -fig 2 åÊ To make quantifying of the materials easier, mix proportion were made up in terms of volume rather than mass. I have decided to adopt previous method to determine the ratio, by using the yellow bucket to measure each ingredient. åÊ åÊ åÊ åÊ åÊ åÊ åÊ The first experiment saw the brick was too runny/wet and unable to hold its shape, which from my opinion caused by incorrect quantity of water (too much) and sand (too little). During this first try out, we have found out that the main problem of the presser is the method of transferring the wet bricks to somewhere where it will be cured. Obviously any good mix wonÛªt have enough strength to hold its shape when been lifted up, since we are not dealing with any clay and minimum amount of cement and sand. The second experiment we conducted generally with the idea to increase the strength by improving ratio of Sand and how different water content will affect workability and final strength and also how well the brick retains itsÛª shape. We reduced bit of water and put on more lime to ensure better binding strength with the fibre and sand. åÊ The result of the second experiment was much more convincing, the brick has much more strength to hold its shape, but we still think we have to reduce the quantity of water. This time we decided to let the brick dry a bit first for about 1 hour on the presser before we moved them on plywood. The Brick is still hardening and the next step will be to test its strength. The second mix we made has a bit of leftover, so the next experiment we will consider reducing a tiny bit of sand or coir. åÊ Day 2-22/03/2013 After the 2nd experiment we have decided to reduce the amount of sand, as to improve its compressibility, and to have less water to see its capability of holding up the shape. This time, we used finer fibre of the coconut, which been cut to approximately 2Ûªinch to see its workability and strength. Because itÛªs finer, the amount compacted in the wheelbarrow is much significant. åÊ For the presser, we improvised a little by putting a plastic sheet to the base plate, to help us move the brick right away. åÊ åÊ The brick that came out was much sturdier, and the lack of water made it drier and better in holding up the shape. With less sand, the brick seemed to be better compressed than before, and it didnÛªt seem to affect its shape. The finer fibre was pretty impressive as we think it was properly mixed and spread better than the previous one, and made the brick easier to compress even though it might have effect on its tensile strength. åÊ The plastic sheet seemed to contain the lime from leaking and it was pretty much collected at the bottom of the brick (where the plastic sheet is). I did some silly mistake by moving the fresh pressed brick on to uneven plywood and made the brick bend a little as it cured. åÊ Day 3-01/04/2013 After a discussion with Ian, we decided to try maximising the percentage of natural fibre to lime/sand/cement and use less water. We also thought of eliminating cement and see how lime behaves. I decided to use small portion of fine sand hoping it can help filling small gap and reduce Û÷caveÛª all around the brick. åÊ åÊ åÊ åÊ åÊ The result we got shown that the brick was too runny, and couldnÛªt hold to its shape, and the fibre used was too little (we couldnÛªt fill up the mould) in comparison to other ingredient. Earlier during the mixing, I noticed that because of the bigger fibre of coir, the mix didnÛªt really well spread and blended evenly with the coir, causing additional water to be added on. åÊ This time we decided to take sometimes (about 30-35mins) to mix the coir and other ingredients thoroughly (figure above). We didnÛªt use cement, as from previous experiment, the lime seemed reliable in gluing up the mix. We added more fibre, but then we wasted 1 portion when we couldnÛªt load them anymore in the mould, hence for the next experiment we were thinking of reducing the ration of fibre or cut them into finer fibre. åÊ The result was pretty impressive, it held its shape well, and one of the reason being is we took quite a while to compress them by hand during loading (about 15mins). We did it layer by layer carefully and pressed them hard especially on the side. Lime and sand and water seemed to mix rather perfect with the coir and the result is as follows; åÊ We recommend using finer fibre as it would help reducing effort to mix them thoroughly and save a lot of time (look good as well). And with lime, curing process does taking a while. Other than that think we already have a really a good ratio now, managed to get rid of cement and maximised the use of fibre. åÊ In this experiment, we used rice husk as the bio fibre to investigate its properties compared to coconut coir. I tried the same ratio as the last experiment and i was dead wrong. The rice husk particle sits together really close leaving minimum gap for other ingredients to blend in. Unlike coconut coir, the 8 portion of rice husk can produce 2 bricks with leftover because of its solid grain. So lime and sand ratio in this experiment went totally wrong, too little to hold 8 portion of rice husk. Learning the problem during mixing, we tried put 1 portion of cement, and it did help a little. We added water significantly to help them bind but it still dry out.. During the loading, because of lack of lime/sand/water, it is really hard to compress them and we only managed to put about 1.5 portion and we wasted the rest of the mix. åÊ The objective this time was to get the right amount of mix for a cube of brick. Based on last experiment, we decided to use 3 portions of the rice husk, hoping it would fill the mould perfectly. And it did, after we compact them carefully and slowly. Every layer we poured, we pressed them using a piece of wood, press it until a little bit of water came out especially at the top and the side. The brick weÛªve got was pretty strong, holding its shape well and have a really smooth rectangle edges except for the top surface where it was a little bit flaky. I thought that happened because we lost a little bit of earlier compression as the top part was too thick and as we closed the lid, it just swept away the compressed surface. åÊ Bio Crete Bricks ÛÒ Building Recycle Point From the last report, I had my best and most suitable ratio of bricks tested in a form of wall with the volunteers. Throughout the week, we have managed to produce 25 pieces of bricks, and a lot about mass production issues has been learnt from it. The presser has come out with a lot of technical issues, and it affected our quality and consistency of the brick (especially the rice husk bricks). We have also invented other way of removing the pressed bricks into the curing area, and this should be taken into consideration if we are getting a new presser. åÊ *further explanation can be found in Bio Crete report attached in the email. However, we managed to produce a sufficient amount of bricks for our wall testing and we have designed a simple recycle point with three partitions, to replace the temporary one in the camp. I decided to use lime instead of cement for mortar. It isnÛªt completely done yet because of the curing duration of lime but itÛªs generally usable now. åÊ ThatÛªs a wrap for now; the next progress will be reported in July, as soon as the summer start, until then take care and thanks for the support! Safuan has returned home to Kuala Lumpur, where he resides in Peninsular Malaysia. He has now commited himself to return and volunteer as staff member for the summer to help see our goals through. Thank you Safuan, looking forward to see you back here for summer season!