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# The mixture is put into templates or a mould matrix
# The mixture is put into templates or a mould matrix
# Applying a compressive force at a rate of 600 k/min for about 50 s for mechanical compaction. <ref name="faukour"/>
# Applying a compressive force at a rate of 600 k/min for about 50 s for mechanical compaction. <ref name="faukour"/>
===Budget Tables ===
 
==Budget Tables ==
The budget tables will include 3 different types of table which are for the purpose of replicating the blocks, the overall cost of manufacturing the blocks, and the research cost.
The budget tables will include 3 different types of table which are for the purpose of replicating the blocks, the overall cost of manufacturing the blocks, and the research cost.



Revision as of 00:08, 3 July 2014

Abstract

The plan to make a building block that is cost effective and will be more environmentally sound while still having high tensile strength. This project is taking place from May 25th to July 5th and will take place in Las Malvinas a community in Santo Domingo. The group will be basing their blocks from rice husks and coconut husks so that the blocks can sustain the weather and pressure while still being environmentally sound.

Background

The ecoladrio project location is in Las Malvinas, a community outside of the main section of Santo Domingo. Our team is made of two Humboldt State students and are taking classes in UNIBE. The block project that the group is conducting is made so that the community in Las Malvinas can create a more inexpensive and sustainable block that will later be used by a local company to substitute regular commercial building blocks.

Objective

The objective of this project is to recreate a cinder block made from products other than solely concrete. This new block must also be more cost and environmentally effective while still being able to withstand the climate and natural disasters that occur in the Dominican Republic.

Criteria

Criteria Constraints Our Weight (0-10)
Aesthetics Must resemble local architecture. 7
Production Cost Must cost less than regular cinder blocks. 10
Durability Must withstand weather and pressure. 10
Material Locality Must attain materials near or within Las Malvinas. 7
Reproducibility Ease to reproduce products. 9
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 8
Environmental Impact Blocks should have a smaller footprint than concrete blocks 7

Literature Review

This is a review of the available literature pertinant to the 2014 Practivistas innnitiative to begin ceating Hullkrete and fiber-crete for the community of Las Malvinas in Santo Domingo. The topics been covered range from the potential materials to the production for construction.

The Community of Las Malvinas

The community of Las Malvinas is a rural barrio located on the North Side of Santo Domingo. The community and Practivistas students have experimented using upcycled materials in other to developed cinder blocks which are less expensive and utilize local resources.

Weather

eco-Block procedure

Constructions norms of structural masonry walls in Dominican Republic (R-027)

In accordance to the constructions norms of structural masonry walls in Dominican Republic (R-0217) “The thickness of concrete blocks walls, used as earthquake resistant structural elements, shall not be less than 0.20 m (8 “)”. [1]

“The ranges of resistance for block units must be 10 kg/cm2 to 65 kg/cm2” (R-027)

Compressive strength of concrete block.png

ELASTIC MODULUS Em= 900·f’m

R-027 says that "Crushing of the masonry strength will be evaluated according to the formula" [1]

Crushing of the masonry strength formula.png

Manufacture and Curing of Block

Joseph J. Shideler, in his Investigation of moisture-volume stability of concrete masonry units with the Portland cement association, they stated “Concrete mixing, molding and curing procedures were established that produced compressive strengths at 72 hours after molding… The molded block were immediately place in a kiln and subjected to an 18-hour curing cycle.” [2]

For the drying process the cycle “consisted of holding the block at room temperature for 2 hours, then raising the kiln temperature to 160F at 40F per hour… until the block reached the required moisture level” [2]

Materials

Rice Husk Ash

The Article "Production and Utilization of Active Rice Husk Ash as a Substitute for Cement" by YAMAMOTO and M. LAKHO was published in 1982 and covers an experiment carried out in Asian with Rice husk ash (RHA). It mentions the interest of using this material as a building source since Mehta and Pitt published a paper introducing the mass production of active RHA in 1974. “These efforts have confirmed that RHA (Rice Husk Ash), if produced properly, was a prospective silicious material not only for plastering but also for production of acid resistant high strength concrete.” The article also include the ratio in which the experiment was carried out and the source they obtained from. The materials used were rice husks,boiler rice husk ash, lime, Portland Cement, and fine aggregate. “Dirt free rice husks were obtained from a rice mill in Thailand. They were stored in plastic bags at their natural moisture content of about 20 %. They were later burnt in a muffle furnace or in the open air to reduce to their ash under various conditions.” “Rice husk ash taken from a boiler of the same mill was also used in this work for comparative purpose.” “Lime used in this investigation was reagent grade calcium hydroxide. It was kept in air tight glass bottles to prevent its carbonation.” This source also specifies the water qualities of using river sand. “Natural river sand was used for making mortar. Its specific gravity, fineness modulus and water absorption were 2.60, 2.75 and 1.40, respectively.” Some of the ratios been used for the experiment are listed below. “The mixing ratio for the mix proportion of Mostars was “Sand-cement ratio of 2.75 by weight was maintained throughout the work. In preparing the blended cement of lime and RHA, lime-RHA ration was initially kept at 2.0 by weight. But it was changed to 0.5 in the later parts of the study after the latter was found to be the optimum. Water lime plus RHA ratio was fixed at either 0.80, 0.65 or 0.60 depending on the purpose of the study. The proportion of RHA in the mixture of Portland cement and RHA was changed from 0 to 70 % by weight.” [3]

marble sludge powder

F. J. Aukour, from the Faculty of Natural Resources and Environment,The Hashemite University, Jordan. In the 3 years period investigation of (Feasibility study of manufacturing concrete eco-blocks using marble sludge powder as raw materials), says "The possibility of using marble sludge powders (MSPs) as a substitute for limestone was investigated over a three year period. The results have shown that appropriate incorporation of MSP can result in favourable characteristics in terms of compression strength 9 N/nm2 at 28 days,and water absorption (7%), anticipating a complimentary usage of sludge as a by-product instead of being waste." [4]

The methodology used by F.J. Aukour,

  1. The collection of Msps.
  2. Sieved and graded of marble powders.
  3. Treatments design "having a certain amount of mixed materials represented in the volume base and each volume unit having its own weight, were derived from the combination of the following four components: Coarse aggregates (A), Fine aggregates (B), cement, and MSP." [4]
  4. The mixture is put into templates or a mould matrix
  5. Applying a compressive force at a rate of 600 k/min for about 50 s for mechanical compaction. [4]

Budget Tables

The budget tables will include 3 different types of table which are for the purpose of replicating the blocks, the overall cost of manufacturing the blocks, and the research cost.

Quantity Material Source Cost (RD$) Total ($)
4 bags Cement Bag Block factory in Las Malvinas 250 /
8 wheelbarrow Sand Block factory in Las Malvinas 120 /
10 sacks Rice hulls Destileria "La Isabella" / /
Total Cost $246.60

Timeline

"Thursday June 19, 2014"

  • Used initial materials gathered and made first batch of blocks.
  • After making blocks cleaned coconuts for upcoming batch and smashed coconuts to size of gravel used in mixes.
  • Finished digging trenches for the police station foundation.
Ingredient Type of measurement Batch 1
Sand 5 gallon bucket 3
Gravel 5 gallon bucket 3
Cement Bag (90 lbs) 1 1/5
Rice Hull Ash (RHA) 5 gallon bucket 15
Caliche 5 gallon bucket 1
Water Gallons 12
Secante Ounces 6
Number Blocks 32
Compression Test ------
"Considerations for Next Batch"
  • Use less water. Mixture was very wet and would produce better results out of the press by using 8-9 gallons of water instead of 12.
  • Use a better sifter for the ash. Most large particulates were filtered out but some larger pieces of hardened concrete were in the mix.

"Friday June 20, 2014"

  • Acquired two 55 gallon drums of sawdust from a coffin maker next to the block factory. Soaked the sawdust in water and a bag of lime per drum overnight for use the next day in blocks.
  • Tied rebar for foundation in the Destacimento.

"Saturday June 21, 2014"

  • Acquired more coconuts for use in future mixes for blocks.
  • Made two batches of sawdust blocks. One using sawdust as a aggregate replacement and a second using sawdust and the coconut shells as aggregate replacements. Cracking occurred in only a few blocks and the workers were optimistic about the quality of the blocks.
  • Continued to dig trenches and tied rebar for the Destacimento.

"Monday June 23, 2014"

  • Tied rebar for the Destacimento.
  • Smashed coconut for future batches

"Tuesday June 24, 2014"

  • Acquired 157 lbs of newspaper from Listin Diario. Tore newspaper for 2 hours with the help of children from the community and the group working on the Destacimento.
  • Acquired a 55 gallon drum to soak the newspaper.
  • Poured concrete at the Destacimento.

References

Template:Reflist

  1. 1.0 1.1 http://www.mopc.gob.do/media/6238/R-027%20REGLAMENTO%20MAMPOSTERIA.pdf
  2. 2.0 2.1 http://stuff.mit.edu/afs/athena/dept/cron/project/concrete-sustainability-hub/Literature%20Review/Building%20Energy/Concerte%20Industry%20Reports/PCA%20CD%20Cement%20Research%20Library%202008/reports/DX003.pdf
  3. http://library.jsce.or.jp/jsce/open/00037/322/322-124102.pdf
  4. 4.0 4.1 4.2 F. J. Aukour. Faculty of Natural Resources and Environment, The Hashemite University, Jordan. (Feasibility study of manufacturing concrete eco-blocks using marble sludge powder as raw materials) www.witpress.com, ISSN 1743-3541
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