Las Malvinas hullkrete 2015: Difference between revisions

Project data

Completed	2015
OKH Manifest	Download

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Practivistas Dominicana Program

• La Yuca
  • Ecoladrillo schoolroom (2011)
  • Rainwater catchment (2014) (2013) (2012) (2011)
  • Small scale renewable energy (2014) (2012) (2011)
  • Schoolroom renovation (2013)
• Las Malvinas
  • Ecoladrillo schoolroom (2012)
  • Botica popular hullkrete (2015) (2013)
  • Eco-block police station (2014)
  • Eco-block testing (2015) (2014)
  • Botica popular ecoladrillo (2013)
  • Rainwater catchment system (2014) (2013)
  • Rainwater feasibility study (2014)
  • Community center shade structure (2014)
• Other
  • Solar workshops (2015)
  • Arroyo Norte waste plastic innovations (2015) (2014)
  • Ghetto2Garden solar power (2014) (2013)

This page discusses the Las Malvinas hullkrete project from summer, 2015. This project includes: designing and testing eco blocks in Las Malvinas that successfully fit the criteria set; and using the best eco blocks to finish as much of the already-started destacamento in Las Malvinas as possible. The project team is composed of a group of six students studying at Cal Poly Humboldt HSU, all of whom are members of Lonny Grafman's Practivistas program.

Background[edit | edit source]

This project was included in Lonny Grafman's Practivistas summer program through Cal Poly Humboldt. It took place from May 22-July 4, 2015 in the small community, Las Malvinas, located in the outskirts of Santo Domingo, Dominican Republic. The Las Malvinas destacamento 2014 began in 2014 and is expected to be finished in 2015. The team of six dug trenches to allow a place for the foundation as well as laid several blocks and rebar to create what is now a 4 foot tall perimeter with an overgrown inner area. This team hopes to complete the wall construction of the destacamento using eco friendly blocks. The decision of which blocks to be used will be made by testing several different recipes researched with the help of the block making factory owned by Vasquez, located in Las Malvinas.

Objective[edit | edit source]

The objective of this project is to construct the destacamento in Las Malvinas in the least carbon intensive way that utilizes as many waste resources as possible while providing education about resources used and creating a perfected recipe for the hullkrete ecoblocks that can then be commercially manufactured to boost the Las Malvinas economy.

Criteria[edit | edit source]

Below, a table of the criteria the hullkrete group decided upon is shown, each weighted with a value of importance: 10 being highest. The criteria is based off of the general consensus that the quantity of recipes for the blocks tested upon was of lesser importance than testing few known recipes and perfecting them so that they could be 1. commercially sold and produced and 2. could be used to build Las Malvina's destacamento.

Literature Review[edit | edit source]

See Las Malvinas hullkrete 2015/Literature Review for the research done on this project.

Construction[edit | edit source]

Making Blocks[edit | edit source]

Below is a gallery displaying the steps taken to make blocks at Vasquez's factory.

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  Fig 1a: Sifting the wood ash obtained from the local distillery. Since it is a waste product it contained broken glass and several nails.

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  Fig 1b: Shoveling and using buckets to put rice hulls into the wheelbarrow.

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  Fig 1c: All materials get poured into the mixer in a specific order, here is directly after rice hulls had been poured in.

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  Fig 1d: Here is sand being put in the mixer. This photo displays the need for masks while working with blocks.

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  Fig 1e:Pouring wood ash into the mixer.

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  Fig 1f: Tanya measuring secante to pour into our block mix. This was only used in our initial testing stage and was no longer used to produce blocks beyond the initial trials.

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  Fig 1g: Shoveling the mix from the mixer into the block maker.

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  Fig 1h: The very noisy block maker that shook and pushed down on the mix to form it into the shape of our blocks.

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  Fig 1i: Fresh blocks right from the shaper.

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  Fig 1j: Using a dolly to transport the fresh blocks to our drying area.

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  Fig 1k: The block making team feeling proud and tired.

Steps to Make Blocks[edit | edit source]

Initially the workers were adding the rice husks first because it was the most abundant material and the basis of our blocks. However, after about 2 batches they noticed that too much of the batch was getting stuck to the bottom of the machine and not being properly mixed and so the order was changed.

Testing Blocks[edit | edit source]

If not given the opportunity to formally test blocks, a manual test can be done to see how easily the blocks can be broke, chipped or cracked.

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  Fig 1a: Some of our blocks were fairly easy to chip off, this was due to the high content of rice hulls.

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  Fig 1b: Lexie using her feet to see if the blocks can be chipped off easily. Also jumping on both ends of the blocks to see if and how the blocks break.

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  Fig 1c: Our highest preforming block, recipe 5, of the first set of test blocks in a compression tester. This compression tester located at P&R Ingeniería on Av. San Martin, Santo Domingo.

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  Fig 1d: Resulting crack from the compression tester on our highest preforming block, recipe 5.

Applying Blocks[edit | edit source]

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  Fig 1a: Annette placing two mortar layers on the outer edges of the already applied layer of blocks.

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  Fig 1b: Kaileigh lifting a block to place it on the mortar layer.

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  Fig 1c: After the block has been placed, mortar is fit in between the blocks.

Filling Blocks[edit | edit source]

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  Fig 1a: Not an actual picture, but the best way to mix the fill mixture is to shovel it all into the center like a mountain and then make a volcano. This was done about 5 times, mountain to volcano, mountain to volcano, until it was all about the same color, and then the water is added.

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  Fig 1b: A mini volcano of mixing materials.

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  Fig 1c: The dry fill mixture, now in volcano style ready to be mixed with a shovel and pickax.

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  Fig 1d: Gregorio is mixing the fill mixture with a shovel which is extremely tedious and difficult.

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  Fig 1e: Gregorio is blending the mixture as someone uses their hands to add water little bit little.

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  Fig f: Here Gregorio is using the pickax to blend the mixture because its a lot easier to move through the gravel in this way.

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  Fig 1g: Pouring the fill mixture down the blocks we had just laid.

Timeline[edit | edit source]

The following is a list of the tasks assigned and achieved as well as the dates.

Costs[edit | edit source]

Below is a table of the costs associated with this hullkrete project.

Recreation Cost Recipe 6[edit | edit source]

The following table describes the cost to make 11 batches of recipe number 6 which yielded 340 blocks.

Recreation Cost Recipe 9[edit | edit source]

The following table describes the cost to make 11 batches of recipe number 9 which yielded 152 blocks.

Tests[edit | edit source]

Recipe 6[edit | edit source]

Using the following recipe for 11 batches, 340 blocks were made

Recipe 9[edit | edit source]

Using the following recipe for 4 batches, 152 blocks were made

Testing results[edit | edit source]

Below, are the recipes used for the Eco Blocks and their results from the compression test performed on them. Please note, each batch produced roughly 24-40 blocks, with multiple rounds each producing 4 blocks at a time. Each batch had an extra amount of cement added into the last couple rounds whose mixture was on the bottom and received less cement initially. This was done with the workers discretion, so recorded quantities are not exact.

Block Recipes

Material	Type of Measurement	Recipe 1 Block 1	Recipe 1 Added Cement	Recipe 2	Recipe 3	Recipe 3 Added Cement	Recipe 4	Recipe 5	Recipe 5 Added Cement	Recipe 6
Ricehull	5 gallon buckets	12	12	12	12	12	12	12	12	4 heaping
Caliche	5 gallon buckets	0	0	0	3	3	3	3	3	4
Sand	5 gal bucket	1	1	1	1	1	1	2	2	2
Gravel	5 gal bucket	0.5	0.5	1	1	1	1	2	2	2
Lime	5kg Bag	1	1	1	1	1	1	1	1	2
Cement	94lb Bag	1.25	${\displaystyle +}$0.25	1 (${\displaystyle +}$.25 bag for last 20 blocks to get cement on dregs of batch that didn't receive as much)	1	${\displaystyle +}$ 2 shovelfuls for last 8 blocks	1 (${\displaystyle +}$.2 shovelfuls for last 16 or so blocks)	1	${\displaystyle +}$0.5 bag for last 8 blocks	1 bag for whole batch
Wood Ash	5gal Bucket	0	0	1	2	2	0	0 (simply because ran out)	0	0
Batch indicator	Symbol sprayed on each block (*Note: batches with added cement marked with original symbol plus single dot except in first batch*)	Line along edge ${\displaystyle +}$ single dot	Line along edge	line along middle (added cement portion marked with additional single dot)	T	T ${\displaystyle +}$ single dot	Two vertical dots (added cement contains extra dot)	Diagonal line	Diagonal line ${\displaystyle +}$ single dot	Infinity sign (or 8)
Weight (kg)		5.52	5.49	7.13	8.68	8.66	8.83	10.15	11.36	6.45
Surface Area (cm2)		576.00	580.65	557.20	568.80	578.16	588.00	574.20	575.65	578.16
Breaking Load (kg)		2680.00	2520.00	4700.00	6060.00	6180.00	10080.00	12320.00	12920.00	4580.00
Breaking Stress (kg/cm2)		4.65	4.34	8.44	10.65	10.69	17.14	21.46	22.44	7.92

Maintenance[edit | edit source]

Maintenance for the destacamento and building blocks include different requirements based upon if the destacamento is going to be built in the near future. It would be best not to keep the eco blocks outside in the weather: sun and rain, day after day if the destacamento is going to be finished being built later on. Also, if the destacamento is going to be delayed being finished, the now somewhat leveled earth floors need to be upkept in that people need to refrain from throwing their basura, trash, into the building- otherwise, the ground will start to build up trash mounds again. However, if the destacamento is going to be built sooner rather than later, plastering should occur as soon as the walls are put up to protect the eco blocks from being at all degraded by the weather and surroundings.

Conclusion[edit | edit source]

Testing results[edit | edit source]

Recipe 5 preformed the best in our compression tests, this, we believe is due to recipe 5 having half the amount of rice hull than the first recipes.

Discussion[edit | edit source]

After our first set of test blocks were made, we were able to conduct physical tests with our feet to determine the strength and what patterns we could find involving rice hull content and strength. Since we were unable to conduct professional tests on our initial test blocks before making more, we used what we learned from our feet tests to decide the recipe to use next. Our second and final time at the block factory we made blocks with a new recipe which was an iteration based on our recipe 5 which preformed the best. We also used the information we learned about the previous recipes to make the iteration. After these blocks were made, we were able to test our initial set of six recipes and were able to officially deduce that recipe 5 was the strongest and was approximately 30% as strong as the Dominican Republic's government requires blocks to be.

Lessons learned[edit | edit source]

There are a plethora of lessons learned from this project. One crucial lesson learned was to plan better. Many times trying to coordinate making eco blocks at Vasquez's factory failed because of a miscommunication of when his space and workers were accessible, and also due to not having all of the necessary supplies. It would have been way more efficient to have the entire group sit down and choose a known recipe to start with and then start making variations of recipes with lists of materials and how many blocks were desired to make in the day and quantities of materials needed to do so. Vasquez's factory is open Monday-Saturday, morning until mid to late afternoon, so the only available times the group was able to work was either full-day Sundays or part-days in the afternoons after the factory closes. The workers hired to help the team make the blocks needed to be notified and asked to stay for pay, and they expected all of the eco block materials to be at the factory and ready to go the day before. Some of the key ingredients to this year's blocks were rice hulls and wood ash. The rice hulls were located an hour away from the community, so a driver with a truck was needed, and the wood ash was off and on available at the local distillery in Las Malvinas- but needed to be sifted twice, which could take several hours depending on how much was needed. These mistakes should be read by future Practivistas students wanting to do more exploring with the blocks.

With the destacamento, it is important to have someone- generally a community member- who knowns what he/she is doing. Someone who excels at building is crucial because there are a lot of aspects to be considered: such as leveling the blocks before adding all of the mortar, or where to add rebar, or how full to pour the mortar down the block holes. This was a lesson learned when two group members showed up at the destacamento ready to finish some layers of wall and soon realized they didn't know quite what they were doing at all. It is important to learn and listen to community members who are experts in the fields of work.

Next steps[edit | edit source]

So now that the building and planning and experimenting is done for the team, what are the next steps? For the community or future Practivistas students, this means more experimenting with making blocks with different variations of materials as well as finish building the destacamento. Building the destacamento with the eco blocks made is important because it makes the building more "green" and locally resourced. If a recipe is found for the eco blocks that is exceptionally efficient, maybe the community and beyond can grow to be more locally resourced and environmental.

Current State[edit | edit source]

The Natural Building team succeeded their goal in an ecological friendly block recipe. The recipe reduces the normal cement content thus cutting costs of manufacture. The blocks were set through compression tests; ones that passed the compression tests were used to continue construction of the destacamento.

As far as the destacamento goes, the image below depicts the before and after shot of the progress made towards building this summer. The amount of work done to this building this summer is significant.

Video: Building a Destacamento[edit | edit source]

Team[edit | edit source]

The Las Malvinas natural building team, Practivistas 2015:

• Carley Bramhill
• Lexie Folkerts
• Tanya Garcia
• Allison Nerby
• Annette Penny
• Kaileigh Vincent-Welling