Booklet on: Challenges and Opportunities in the Production and Purchase of Good Quality Blocks
- Build Change tested 129 blocks from 43 locations in Port-au-Prince and found an average compressive strength of 4.45 MPa, compared with the 10 MPa guideline.
- All 45 block makers in the program habitually used about 5 wheelbarrows of sand for one bag of cement, a ratio of 1:12.
- Build Change recommends a mix of 1:7, one part cement to 7 parts sand, which yields 25 to 30 blocks per bag of cement.
- After training, block makers regularly produce blocks above 7 MPa, and more than 20 are certified for blocks above 10 MPa.
- Good blocks cost 35 to 40 gourdes each, which is 40% to 60% more than a bad block, and low demand discourages block makers from making them.
The booklet reports on the capacity training that Build Change and Save the Children have given to concrete masonry unit makers around Port-au-Prince since June 2011, after a 2010 pilot with 9 block makers. Build Change tested 129 blocks from 43 locations and found an average compressive strength of 4.45 MPa, less than half the 10 MPa guideline of the Ministry of Public Works, Transport and Communication (MTPTC).
Part 1 describes a seven-week training method and four recommendations: a cement to sand ratio of 1:7, careful selection of aggregates, sufficient mixing and compaction, and adequate curing. Part 2 addresses agencies that buy blocks. Good blocks sell at 35 to 40 gourdes each, compared with 25 gourdes for a bad block, and the booklet asks agencies to buy from certified block makers to create a market. Build Change reports that more than 20 block makers are certified to produce blocks above 10 MPa.
How to cite
Build Change, 2012, Booklet on: Challenges and Opportunities in the Production and Purchase of Good Quality Blocks, accessed via HaitiDocs, https://www.haitidocs.org/doc/build-change-2012-good-quality-blocks-booklet
- Rights holder
- Build Change