This project was part of the Summer 2013 Practivistas Dominicana project, led by Lonny Grafman in the Dominican Republic. Five students, three from Cal Poly Humboldt (HSU) in California and two from Universidad Iberoamericana (UNIBE) in Santo Domingo, collaborated with the community of Las Malvinas to construct three walls for a "Botica Popular" in the community. This experimented with cinder blocks, or concrete masonry units (CMUs) made of various upcycled materials such as sawdust, paper and rice hulls mixed with cement and pressed using an industrial cinder block maker. At the same time another team worked on building an internal wall out of ecoladrillo, or upcycled plastic bottles.
Las Malvinas is a rural barrio on the Northern outskirts of Santo Domingo, next to the La Isabela industrial zone. Las Malvinas and Practavistas began working together in 2012, when together they built a schoolhouse out of ecoladrillo and papercrete blocks. Through a series of public meetings Las Malvinas community members have identified and prioritized a list of needs. On that list are access to running water and medicine. To address the need for water a team of motivated community leaders constructed a large cistern (approx. 50 cubic meters). An engineer from UNIBE assisted in the design. To address the need for medicine the two student teams mentioned above worked with community members to construct a Botica Popular. The Botica Popular sits partially on top of the cistern and is approximately 6 meters long and 3 meters wide.
Botica Popular[edit | edit source]
Boticas populares are neighborhood pharmacies that provide medications at cost price. They are part of government public health campaign called El Programa de Medicamentos Esenciales or "Essential Drugs Program" (PROMESE). Established in 1984 by presidential decree, PROMESE is the Dominican Republic's central supplier of medications and medical supplies with a mission of ensuring quality, low-cost access to the nation's public health system, Sistema Publico Nacional de Salud. PROMESE has provided greater medical coverage to the population by optimizing public health spending with the implementation of an economy of scale and buying medications and medical supplies in larger volumes. The "Essential Drugs Program" directly serves public and military hospitals, boticas populares, and rural clinics.
For boticas populares, the program fronts the medications and accepts payment at cost price upon distribution to the patient. Las Malvinas does not have a local clinic or hospital. The nearest hospital is Moscosos Puello about 5 km away.
Objective[edit | edit source]
The community of Las Malvinas is seeking to construct a Botica Popular, or government-funded pharmacy, in their community. The objective of this project was to build two of the four walls of the Botica using alternative masonry and to erect the complete Botica by 5 July 2013. This student team fabricated building blocks with sawdust, rice hulls or paper mixed with cement and pressed in an industrial block press. With the climate in the Dominican Republic, the blocks need to be able to withstand heat, rain and the test of time.
Part of the objective of this project was to find a building material, specifically a fiber-concrete mixture, that the community will be able to utilize in the future to make more blocks for other projects. As such, final product should be composed of locally purchased or acquired materials, and have a low cost, both monetary and environmental.
Entirely concrete cinderblocks have a high embedded energy, with an average of 0.67 MJ/kg and 0.073 kg Co2 per kg with a density of 1450 kg/m3. The new blocks should have less embedded energy per block.
Criteria[edit | edit source]
This section was designed to assist in the determination of the different aspects of this project. The group chose these criteria based on the expectations of the client, the class and personal interest. Weighing the criteria allows for focus on certain elements of the project to ensure satisfaction with the final product.
|Criteria||Constraints||Our Weight (0-10)|
|Aesthetics||Must resemble local architecture||6|
|Production Cost||Must cost less to produce than the common cinder block||10|
|Durability||Must withstand elements, impact and pressure||9|
|Material Locality||Must attain materials within or near Las Malvinas||7|
|Potential for Reproduction||Ease of access to materials as well as documentation||8|
|Safety||Must be safe both structurally and in the process of creation||10|
|Community Involvement||Must include the local community members in the creation of this project||10|
|Environmental Impact||Blocks should have a smaller footprint than concrete blocks||7|
Literature Review[edit | edit source]
See Las Malvinas Botica Popular fiber-crete 2013/Literature Review for the research done on this project.
How To[edit | edit source]
Make papercrete[edit | edit source]
|Gather materials. We received misprinted newspaper from Listin Diario - a newspaper based in Santo Domingo. Cost was minimal, they only asked for what they would otherwise have received from the recycling center. Sand, cement, lime, rice hull ash and drying agent were also used in our blocks. The drying agent was necessary due to continual rains and the slow drying time of paper and rice hull blocks.|
|Tear paper for pulping. Initially we did this by hand, but later we has access to a paper shredder (recommended)|
|Soak paper in water and lime. Approximately 1/8 bag of lime was used in a 55 gallon barrel full of paper and water. Paper should be soaked overnight before pulping, although we also experimented with dry-pulping paper.|
|Pulp paper. We used a drill and ingenious welded attachment for pulping. Paper should be throughly wet for the pulping process for ease of pulping and to make smaller pulp. We experimented with pulping only damp paper to decrease drying time, however due to some confusion in block placement after pressing we were unable to tell how this affected the blocks. Drier paper cannot be pulped as thoroughly as wet paper, and this could account for a discrepancy we discovered in the strength of our papercrete blocks.|
|Dry the paper. It should be moist but excrete no water when squeezed so that excess water will not disrupt the ratios in the mixture and wash away cement in pressing. Ideally we tried to do this in the sun to avoid compaction of pulped paper, however due to continued rain we resorted to other means of drying the paper. We put the paper in rice hull bags and pressed it to remove excess moisture before laying it in the sun. This significantly accelerated drying time and we dry-pulped it afterwards to reduce large chunks. Dry-pulped paper did not have to be pressed and thus did not have to be re-pulped. Another method that was suggested was a centrifuge, and this would likely be effective.|
|Mix and press. We had access to an industrial cement mixer and block presser for this step. The final mixture we used for papercrete was 3 wheelbarrows pulped and dried paper (assuming one wheelbarrow = 5 five-gallon buckets), 1.5 wheelbarrows sand, 2 five-gallon buckets of rice ash, 1 bag cement and 6 fluid ounces of Vinaldom SA-600, the quick-drying agent. Water was added as needed.|
|Have caution after the blocks are pressed to minimize breakage in between the machine and the drying area. Carrying by hand is recommended.|
|Wet blocks periodically as they dry to reduce cracking and ensure proper set of blocks. Papercrete tends to hold moisture so use discretion.|
Make HullKrete[edit | edit source]
|Gather materials. We received a donation of rice hulls and rice ash from a nearby distillery that burns the hulls for energy. Sand and gravel were donated from the block factory and cement was purchased from the same. A quick-dry additive, Vinaldom-600, was purchased at a nearby ferreteria (hardware store).|
|Prepare mixture - we had two final successful mixtures. The first mixture contained 2.5 wheelbarrows (1 wheelbarrow = 5 five-gallon buckets) of rice hull, 2 wheelbarrows sand, one wheelbarrow gravel, one bag cement and 4 fl. oz of the V-600. The second mixture was exactly the same with and added half-wheelbarrow of rice hull, bringing the total up to 3.|
|Mix thoroughly and press, we used and industrial cement mixer and mixed dry ingredients first, adding the drying agent diluted with water. Add water until the mixture holds together, but is not overly saturated.|
|Have caution after the blocks are pressed to minimize breakage in between the machine and the drying area. Carrying by hand is recommended.|
|Wet blocks periodically as they dry to reduce cracking and ensure proper set of blocks. This is particularly important in hot areas, try to keep blocks out of direct sunlight if this is the case.|
Strength Testing[edit | edit source]
Price Comparison[edit | edit source]
We conducted a price comparative analysis between the final block mixes and the blocks made at the factory. Both the blocks of rice hull and the blocks of papercrete were cheaper than standard blocks found at the factory based upon price comparisons of materials. This links to view the chart, which also includes the final mixtures we used and the number of blocks from each mixture.
Budget[edit | edit source]
Following is our budget for this project. Costs in both Dominican pesos (DR $) and US Dollars (US $) are included.
|Material||Quantity||Source||Cost per unit (DR$)||Cost per unit (US$)||Total Cost (US$)|
|Rice Hulls||35 bags||Collected from the brewery||200.00||4.90(labor and bag purchase)||4.90|
|Paper||550 pounds||Acquired from Listin Diario||580.00(recycle fee), 800.00(shredding)||14.00(recycle fee), 19.50(shredding)||33.50|
|Cement||21 (94 pound bags)||Purchased from block factory||280.00/bag||6.83||143.43|
|Lime||local hardware store||50.00/bag||1.22/bag||12.20|
|Sand and gravel||buckets||Provided by block factory||0.00||0.00||0.00|
|Rice Fly Ash||3 bags||Provided by brewery||0.00||0.00||0.00|
|Paper pulper||Attachment for power drill||Created by community member|
|Building materials||Buckets, barrels, applicators, shovels, etc.||Borrowed from various community members||0.00||0.00||0.00|
|Transportation of materials||Use of trucks||Community members||0.00||0.00||0.00|
|Tarp||1 large||Hardware store|
|Safety equipment||Gloves and dust masks||Local stores||164.00/gloves 82.00/masks||4.00/gloves 2.00/masks||6.00|
|Block pressing machine and mixer||Presses 4 blocks at a time||Block factory||0.00||0.00||0.00|
|Sawdust||4 barrels of various textures||Acquired from coffin maker||0.00||0.00||0.00|
|Secante (cement drying agent)||1 gallon||Purchased from hardware store||400.00||9.75||9.75|
Timeline[edit | edit source]
This timeline includes information about our progress throughout the project. It records the amount of time and preparation involved in creating both the blocks and the constructing the Botica Popular.
Friday June 7, 2013
Making Blocks[edit | edit source]
Saturday June 8
- First day to work on mixes. We went to Las Malvinas in the morning and, with Ginger's help, secured a barrel of sawdust from the coffin manufacturer who will be providing that material and the block-making site next door where we and members of the community will be doing experiments and making blocks with sawdust and other materials. We also were given two bags of lime and loaned two barrels for mixing the sawdust, lime and water to soak. After an initial mix, the owner of the plant arrived and made some changes to the mixture we had put together, encouraging us to "go big" with our experiments. There was a high level of interest from the community members who came to work with us - they really ended up taking over much of the work, sifting, mixing and all the while peppering us with questions. A kid from the community spent most of the afternoon with us helping mix the sawdust, lime and water. We will be returning to the site on Wednesday to try more mixes and Thursday is the day to press blocks.
Wednesday, June 12
Thursday, June 13
|Ingredient||Type of measurement||Mix 1 Qty||Mix 2 Qty||Mix 3 Qty||Mix 4 Qty|
|Sand||5 gallon bucket||2||2||1.5||1.5|
|Gravel||5 gallon bucket||0||2||0.5||0.5|
|Sawdust||5 gallon bucket||14||14||10||0|
|Rice Hull||5 gallon bucket||0||0||0||10|
|Cement||Bag (90 lbs)||1||1||0.5||0.5|
|Rice Hull Ash (RHA)||5 gallon bucket||1/4||1/4||1/6||1/6|
|Lime||Bag (approx. 1 5-gallon bucket)||1||1||2/3||2/3|
|Compression Test||Crumbled||Crumbled||Crumbled||Held up|
Saturday, June 15
Sunday, June 16
- Assessed the blocks again, sawdust blocks are still wet, rice hull blocks are closer to dry. The sawdust may not be used in the final round, testing will continue before this is a final determination. The rice hull blocks were found capable of supporting human weight, and general consensus is that they will work well with more cement. Papercrete is also going to be tested in the next round.
- The very fine sawdust from the coffin manufacturers proved challenging to sift. It may not be used in blocks, it might be used in the finish for the Botica.
Monday, June 17
- Sought sources for waste newspaper. Attempted several contacts.
- Determined plan of action for block testing round 2.
Tuesday, June 18
- A source for newspaper for making papercrete was secured.
- We tore up and set paper to soak in water and lime for testing on Thursday or Friday.
- Determined that using the 4 inch sized block forms will not make a significant difference for the tests: the forms in the machine will not be changed back to 6 inch blocks until Monday.
- Seeking a paint mixer to pulp the paper for blocks.
Wednesday, June 19
- Secured the rice hull source for tests and block making, we should have rice hulls to use tomorrow.
- Joel found an admixture that we can use to accelerate the drying of the blocks. We will be experimenting with adding it when we make the test blocks.
Thursday, June 20
- Worked on leveling the area that will be underneath the floor of the Botica, it was built up with a large pile of dirt from the cistern.
- Discussed need for a paper pulper. Initially we were going to find a paint mixer, however some community members knew a welder nearby who would be able to weld us a tool for pulping paper.
Friday, June 21
- Tore more newspaper
Saturday, June 22
- In order to dry out the paper we soaked, the pulp was put into rice hull bags and pressed by stepping on it until it was dry enough to be used in the mixture. This was even more effective with the added weight of giving a kid a piggy back ride.
- One the paper was dry enough and the workers were ready, we pressed six more mixtures, this time adding a drying agent to accelerate the rate of set and reduce dry time of the blocks. None of these mixtures contained sawdust.
Sunday, June 23
- Plastering commenced on the cistern today, and some of our group had the opportunity to help with that process and learn cement plastering skills.
- More paper was pulped and torn today as well as laid out to dry for the next block pressing
Monday, June 24
- Shredded more paper by hand, Joell contacted a friend with a paper shredder to accelerate that process.
- Pulped paper and set out on a tarp to dry in the sun. This process has been slowed by daily rain.
Tuesday, June 25
- Pulped the paper from the day before.
- Worked to dry paper for pressing blocks on Thursday
- Received the shredded paper in the evening and set it to soak.
Wednesday, June 26
- Discussed block pressing with respect to day, community involvement and mixes to use. We are working on a spreadsheet to determine the relative cost of different blocks to aid in determining which mixture to use for the Botica.
- Pulped more paper for block pressing tomorrow.
Thursday, June 27
- Pulped and dried more newspaper, we are going to experiment with pulping methods. One version of paper pulping involves immersing the paper in water and pulping while very wet, then allowing the paper to dry before adding it to concrete. Another possibility is that the paper can be wetted minimally and pulped, allowing for more expediency in the making of papercrete.
- A sudden rainstorm kept us from being able to press blocks, they shall be pressed tomorrow instead.
Friday, June 28
- Pulped yet more paper.
- Lay paper out to dry=.
- Made first part of blocks for the Botica, three different rice-hull crete (HullKrete). Because of measuring error, one set of blocks had to be retried. The owner of the block factory offered a mixture of his own and we also re-tried the first HullKrete mixture with increased cement.
- Re-analyzed the spreadsheet for determining relative cost of fibercrete blocks versus conventional blocks.
- Communicated with Jacob to see if he is interested in testing the blocks at UNIBE with a machine. He is, and the tests will take place on Monday.
|Final Blocks/Final Test round 1|
|Ingredient||Type of measurement||HullKrete Final Weirdness||HullKrete Vasquez Final||Original HullKrete Revisited|
|Sand||5 gallon bucket||10||10||3|
|Gravel||5 gallon bucket||2||5||1|
|Rice Hull||5 gallon bucket||15||12.5||20|
|Cement||Bag (95 lbs)||1.5||1||1.5|
|Rice Hull Ash (RHA)||5 gallon bucket||1.25||0||0.5|
|Lime||Bag (approx. 1 5-gallon bucket)||0||0||1|
|AS 600 (Drying Agent)||Fluid Ounces||6||4||6|
|Number repetitions of mixture||2||1||1|
|Total Number Blocks||60||52||Machine broke halfway through pressing. Incomplete.|
|1 wheelbarrow=5 five-gallon buckets|
Saturday, June 29
- Pressed over 300 blocks: most were HullKrete with two different mixtures and there were three different mixtures for papercrete: one containing wet-pulped paper only, one with "dry - pulped" paper only and one with a mixture of the two. Work on the Botica recommences when the blocks are dry. Work continues on the cistern, and wood for the cap is being accumulated.
|Final Blocks Round 2|
|Ingredient||Type of measurement||HullKrete Final Vasquez*||Extra HullKrete Final||Papercrete Final Wet Pulp||Papercrete Final Dry Pulp||Papercrete Final Mix|
|Sand||5 gallon bucket||12 (10 +2 of a sand-clay mixture)||12 (10 +2 of a sand-clay mixture)||7.5||7.5||7.5|
|Gravel||5 gallon bucket||5||5||0||0||0|
|Paper Pulp||5 gallon bucket||0||0||15 wet pulped||15 dry pulped||10 dry, 5 wet pulped|
|Rice Hull||5 gallon bucket||12.5||15||0||0||0|
|Cement||Bag (95 lbs)||1||1||1||1||1|
|Rice Hull Ash (RHA)||5 gallon bucket||2||2||2||2||2|
|AS 600 (Drying Agent)||Fluid Ounces||4||4||6||6||6|
|Number repetitions of mixture||3||1||1||1||1|
|Total Number Blocks|
|1 wheelbarrow=5 five-gallon buckets|
|*This mix was repeated and changed slightly|
Building the Botica[edit | edit source]
Sunday, June 30
- Blocks that were pressed on Friday were dry enough today to use for construction, so several feet of height was added to the walls of the Botica storage area today. A cement and sand-based mortar is being used and the holes of the blocks for the storage area are being filled with concrete. The filling is added for increased security purposes.
Monday, July 1
- The cap for the cistern was created. This involved tying in rebar on the wood cap and then pouring and leveling cement.
Tuesday, July 2
- The cistern cap was dry today and building commenced.
- All three walls are in progress and columns for the interior wall were built with blocks.
Wednesday, July 3
- One wall completed, another one nearly finished and the third is approximately two thirds done. One more full workday and the walls will be finished.
Thursday, July 4
- Second wall finished, third wall will be finished either Friday or Saturday.
- Final presentations in La Zona Colonial Centro Cultural de Espana took place in the evening.
Friday, July 5
Saturday, July 6
- Plastering is under way on the walls.
- A wood frame was build for pouring the biga - essentially a concrete cap to the walls that will increase the structural strength of the building.
- Biga poured.
Sunday, July 7
- Work continued in preparation for laying the roof of the Botica.
- Ecoladrillo wall plastered
- Plastering continues on the HullKrete walls, a truth window is added on the east wall.