Characteristics of Rubble Debris in the Port-au-Prince Metropolitan Area
Summary: An LNBTP paper on whether the rubble left by the 2010 earthquake can be turned into construction material. About 5 cubic meters of debris were sampled at Truitier, the main storage and recycling site, and analyzed mineralogically, chemically and physico-mechanically in the LNBTP, BME and Faculty of Sciences laboratories. The material is more than 59 percent limestone with gravel, sand, clay and plant debris, and the paper concludes it must be rejected for ordinary-quality concrete while remaining usable, once treated, in masonry including block-making and possibly as road base course.
Key Findings
- The verdict is a rejection with a reuse path, not a blanket one. Debris from Truitier must be rejected for ordinary-quality concrete, but can be recycled into masonry work including block-making, and, once treated, into pavement base course or the wearing course of earth roads kept under a regular maintenance program.
- The number that decides it is the 28-day strength: about 22.8 MPa for concrete made with Truitier debris, with the formulation study's control specimens ranging from 22.4 to 23 MPa. That narrow band is what the authors read as confirmation rather than a marginal result.
- Composition explains the limit. The debris averages more than 59 percent limestone, with gravel and sand, clays and plant debris mixed in, so it is neither a clean aggregate nor an inert fill.
- One risk was checked and not found: internal sulfate reactions were not revealed in the tests, which matters because sulfate attack would rule out reuse entirely rather than downgrade it.
- The non-destructive methods validated themselves against the destructive ones. Ultrasonic velocity and rebound-hammer readings on the concrete cylinders, taken to gauge void content and internal microcracking, correlated well with the unconfined compression strengths, which supports using them for field control where crushing specimens is not possible.
- The institutional point is worth recording: the work is the product of three state laboratories, LNBTP, BME and the Faculty of Sciences, over about five months of technical study, under the project on managing rubble debris in metropolitan Port-au-Prince and partly financed by UNDP.
- A record-quality note: this document's corpus title previously described it as a seismic microzonation of metropolitan Port-au-Prince, which it is not. The title, summaries and findings have been rewritten from the document itself.
How to cite
National Laboratory for Buildings and Public Works (LNBTP), 2014, Characteristics of Rubble Debris in the Port-au-Prince Metropolitan Area, https://lnbtp.gouv.ht/publications/GeoRegina14Paper120.pdf