Bang It Out!

The Haitian approach to work follows the dictum, “Work requires banging.” Most Haitians are remarkably strong, and much of the work site camaraderie is based on shared displays of physical prowess.  There is nothing praiseworthy in the carpenter who cuts concrete formwork with such precision that it slides into place.  Ah, but if the plywood is a too long and the carpenter can poise a mallet over his head, swing a giant arc and force it into submission, that is work.  Better yet, the wood does not comply at once, so the worker has the opportunity to pound repeatedly, creating reverberation over the entire site.  Of course if the plywood is cut too short, the carpenter has a similar opportunity, force fitting shims to fill the gap.

A concrete building is essentially built twice. First we build it in wood, creating formwork that takes the inverse shape of our design, molds of columns, beams and floors.  Concrete is terrific at withstanding forces that push on it (compression), but lousy when pulled apart (tension), so we hang steel inside the concrete, which we call reinforcing, or rebar.  The steel, encased in the concrete, takes care of the tension very well, but it must be fully covered by the concrete, for exposed steel will rust and deteriorate.  When building up from the ground, columns and walls, we install the reinforcing first, and the formwork is built around it.  For elements in the air, beams and floor slabs, we install the formwork first, and then fill it with reinforcing.  Either approach offers multiple opportunities for banging.

Reinforcing must be installed straight and plumb, the steel cut, bent and tied off with thin wire called fille alegature, which might be the longest word in Creole.  Banging 5/8” diameter steel rod can’t do much of anything to it, so gratuitous banging goes on all day to no real effect.  Installing the formwork around it is the real fun.  There are a few important rules to follow. The walls need to be straight, and they need to have clearance around the steel; if the steel touches the formwork, it will be exposed to air in the finished product, which will cause the steel to rust when wet.  Rusty steel is weak steel.  We require at least 1-1/2” of cover, 2” is preferable.  We never get it.  The walls are supposed to be 12” wide.  If they are 13 or 14 inches wide, no matter, so long as they are consistent.  But there is no fun in erecting a piece of formwork and just letting it stand there.  The carpenters routinely install the formwork about 10 or 11 inches wide. The result, of course, is that the reinforcing is too close to the walls, which then affords the wonderful opportunity to insert cleats and stone shims and hammer the forms wider apart.  This also affords the opportunity to stop work and negotiate, a pastime that they love and I loathe. I identify location after location with insufficient clearance and the carpenters argue.  They are in a no lose situation; if I prevail they get to bang some more, if I capitulate, they have triumphed over the blan.

We have yet to complete one concrete pour with a full 1-1/2” cover everywhere.  The engineers back in the States would be disgusted with my track record, but then again, they are back in the States while I am here surrounded by fifty really strong guys who love to swing their big mallets. I console myself that Haiti is not New England.  We have no freeze / thaw cycles that will spall the concrete and expose reinforcing, and in Haiti the finished concrete is covered with a thick parge that will offer another level of protection.

Above ground walls are built of concrete masonry units (CMU), modular block that are 16” long by 8” high by 8” wide.  Standard Haitian block has three voids in them.  The problem with three hole block is that when you stagger the block vertically, the holes do not align.  Many people died in the earthquake when unreinforced CMU walls fell on them, so we add reinforcing to every row of block and vertical rebar throughout our walls.  We custom fabricate two hole block (US standard) so that if the crews offset the blocks on each course by 8”, the holes line up, as do the vertical reinforcing bars in each hole.  It sounds so simple, yet we never quite get it right.

We carefully set vertical reinforcing in the concrete foundation at 16” on center (oc), hoist the blocks up and slide them into place.  The mason’s like to work as pairs, and prefer to start both ends of a wall and work towards the middle.  The result, of course, is that the middle block is either too short of too long.  An opportunity for banging!  Over a few courses the vertical joints shift so much the vertical rebar no longer align with the holes.  The masons bang a crimp in a vertical rebar to shift it to a new void; often as not we wind up with reinforcing 8” oc in some locations and 24” in others.  The virtues of beginning the wall in the middle and working towards each end (where we frame into a column to be poured later and therefore have some slack), seem clear to me, but no matter how I try, and have the bosses explain in Creole, the workers give me their weary nod and then start a new row from opposing sides.

Haiti is a tradition bound country, and their concrete construction methods have evolved over hundreds of years.  The earthquake proved their techniques inadequate, if you think like an engineer.  But Haitians put more faith in tradition than calculations, and are just as apt to credit the mystical for the trauma of their earthquake as they are to credit physics; so trying to explain why a particular piece of steel is necessary to protect them in the future is a daunting challenge. I comfort myself that we have come so far; that the walls are being reinforced, if not perfectly, and they are tied to the columns, fairly well, and the concrete covers the reinforcing, good enough.   The quality of the work is increasing, ever so slowly.  We make progress every day, we tear out and rebuild less and less all the time.  And when we hit an impasse, the workers find a way to bang it out, which always makes everyone feel better.

 

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About paulefallon

Greetings reader. I am a writer, architect, cyclist and father from Cambridge, MA. My primary blog, theawkwardpose.com is an archive of all my published writing. The title refers to a sequence of three yoga positions that increase focus and build strength by shifting the body’s center of gravity. The objective is balance without stability. My writing addresses opposing tension in our world, and my attempt to find balance through understanding that opposition. During 2015-2106 I am cycling through all 48 mainland United States and asking the question "How will we live tomorrow?" That journey is chronicled in a dedicated blog, www.howwillwelivetomorrw.com, that includes personal writing related to my adventure as well as others' responses to my question. Thank you for visiting.
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