how to build back better in Haiti with CEMENT (on white sand & add rocks)

[Ivan Olsen]

How to ""Build Back Better""  in Haiti with reference to CEMENT.

Do not add white sand, it is now Haitian LAW since the earthquake, and you must add gravel (aggregate, rock).

Please Help spread the word.

peace

ivan

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http://haitirewired.wired.com/

(it is the first artical on 11-29-11)

posted by Greg Higgins Nov 27, 2011 

On the road to Aquin: building back the same?

One of my goals in visiting Haiti for the first time in September was to get a general idea about whether building back better was in fact happening.  Of course, six days in Haiti was hardly enough to make anything but cursory observations, so I limited much of my time to looking for evidence of whether or not weak limestone sand and aggregate was still being used.  Back in February, 2010, a news article caught my eye that offered a ray of hope.  A month after the earthquake the Government of Haiti banned the use of white quarry sand for structural purposes:http://seattletimes.nwsource.com/html/nationworld/2011078252_apcbhaitiearthquakeconstruction.html

Since weak concrete, and associated poor construction techniques, arguably led to a majority of the deaths in the quake, the Government’s action certainly made sense.  White quarry sand, often called La Boule sand, was discussed at length in the Architecture for Haiti (AFH) group last May and June (currently forum pages 108-110). Comments centered on sourcing higher quality sand from river beds, and what the vast quantities of the sand and aggregate required would do to Haiti’s river beds.  This question, among many others surrounding the sourcing of these basic materials, remains a huge conundrum. 

Here is an excerpt from an engineering master’s thesis written by Havanna Radford that gets right to the point:

When asked how the concrete quality is assured, the Construction Sector Advisor for Tearfund replied: “There is no quality assurance. The majority of the concrete I’ve seen uses pulverised chalk with sand as aggregate, without any gravel involved. The standard way of mixing concrete seems to be by weight of cement per cubic metre, typically 250kg/m3, and they don’t specify how much aggregate or sand should be in it. Even the qualified engineers do that, and it’s not good enough."

The EERI reported that fine aggregate is sourced from nearby limestone quarry sites. Use of light coloured, weak limestone from the largest quarry, La Boule, was banned for aggregate use due to its weakness, however its use persists (EERI, 2010). Local people are often seen manually screening the aggregates into piles ready for a concrete mix, <snip>.

[ Thesis found here: http://sp.cege.ucl.ac.uk/MSc%20Projects/2009-2010/Earthquake%20Eng%20-%20Radford.pdf.  This EERI report covers many issues concerning poor quality materials and construction techniques:http://www.eeri.org/site/images/eeri_newsletter/2010_pdf/Haiti_Rpt_2.pdf ]

And does it persist; way beyond my worst expectations!  Piles of the white limestone were everywhere along the road from Port-au-Prince to Aquin, a small town I visited on the south coast, approximately 90 miles (145km) from Port-au-Prince.  Here are just a few examples:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

The challenges evidenced in these photos are extreme, both in terms of the materials involved and the techniques used in construction.  There are many serious efforts now underway in Haiti to address the quality control issues regarding confined masonry construction, and concrete in general (see Footnote).  However important this work is, it may be a drop in the bucket, as what I witnessed suggests.  There appears to be two rebuilding paths in Haiti: the efforts by various NGOs and faith-based organizations to build back better (but not in every case), and those not seemingly touched by these organizations; regular folks who have been building the same way for decades, and are continuing as if the earthquake never happened.

My observations also confirmed one of the key findings listed in a US State Department’s Workshop on “Rebuilding for Resilience” issued in March, 2010 (http://www.state.gov/p/io/rls/fs/139155.htm ):

Owner-built construction represents 80-90% of the construction within Haiti, and thus building back better requires improvements to the owner-built construction process.

The owner-builder is a key component of the Haitian culture, and they build with blocks and concrete. Do-it-yourself is often how it’s done in Haiti (I recognize that not all the photographs above are of owner-builder activity).  I can’t imagine this changing much in the foreseeable future.  Until solutions are identified that intervene to substitute high quality sand and aggregate for quarry sourced materials, and building techniques are improved, building back better will ring hollow for the majority of Haitians.

To make any progress, the first step must be a thorough inventory of Haiti’s high quality sand and aggregate; where is it, and how much is there?  Then, assuming these materials are available in adequate amounts, a means to get it into the dump trucks plying the roads must be found.  It will take a massive effort to improve the sand and aggregate supply stream.  This must be done.

 

FOOTNOTE: Many readers here are familiar with the work of Haiti Rewired member Bruce Christensen and his extraordinary efforts to improve Haiti’s concrete supply chain with the “Cement Trust” organization: http://cementtrust.wordpress.com/ .  In my view, their messages concerning “fixing the concrete supply chain” in Haiti must be taken seriously before building back better can begin in any significant way.  There is also a “Cement Trust” discussion group on Haiti Rewired:http://haitirewired.wired.com/group/cementtrust

Of course the other critical issue is the level of workmanship involved, such as the tendency to leave voids in the concrete, which leads to moisture penetration, causing rebar to rust.  There are many NGOs and other organizations that are working on teaching Haitians improved building techniques, Build Change and Extollo International are two that I think stand out:

http://www.buildchange.org/haiti.html

http://www.extollointernational.org/

Another major contribution that has taken place is the development of the “Confined Masonry Workshop Handbook”.  This document, co-authored by AIDG, AWB and Haiti Rewired, and edited by Craig Totten, P.E., was covered extensively by Derek Xava, and others, in the “Architecture for Haiti” group here on Haiti Rewired:

http://www.aidg.org/documents/CM-Handout%20MASTER%20v3%20English.pdf

I'm sure I have missed other groups making important contributions, and I apologize in advance.  Forum participants, can, of course, add organizations working on these problems through comments.