Tree Likkle Birds

If you have been paying attention, you may have figured out that three major mistakes were made on this project (as well as the multitudes of small mistakes). The worst these was the first of these (and it’s sequel), although all three were tragic, at least to the longevity of the roadway.

Back in the day, shortly after the Koreans quit, we recommended that they be fired, sacked, let go,… made redundant. Instead, the Client’s Project Director opted to keep them on board.

So then, we were in a quandary. How do you build a job with a Contractor who does not want to work? In this case, the Client’s Project Director decided to split the project into vertically subcontracted portions, which resulted in a current and continuing blame game regarding completion dates and quality of the underlying works.
The worst mistake, however, was the decision by the Client’s Project Director to reduce the thickness of the pavement.

During the design process, the Company traversed the North Coast and ascertained the condition of the existing pavement. Using high technology methodologies like the “falling weight deflectometer” (where you drop a big hunk of something on the pavement and listen to the thump), and lower technology methodologies like “taking a good look”, combined with estimates as to projected traffic volumes over time, a design for the proposed pavement was developed.

In the more heavily traveled areas of this road, and in areas that would be reconstructed, the Company proposed a subgrade of well compacted marl, then 350 millimeters of select material, then 100 millimeters of crushed stone, then 150 millimeters of asphalt cement concrete. We reckoned (remember that we are an Midwestern Company, where reckoning is inbred) that this would provide for a twenty year functional lifespan, at which point the roadway could be milled and resurfaced and used for another twenty years.

For reasons unknown to me (although money in some form or another might have had something to do with it), the tender documents show the depth of the asphalt layer to be only 85 millimeters. Now, while each layer of the pavement structure adds to its strength, the asphalt layer adds more strength but with greater cost per unit depth. A good pavement design will balance the performance of the various layers with their varying costs to achieve the optimal roadway. In reducing the asphalt layer by 65 millimeters (43%), the projected life of the pavement was reduced by 75%, to only five years. Based upon the original Contract prices, this major loss saved less than 8% of the total Contract cost.

This was lunacy, and a lunacy soon to be repeated, for shortly after the decision was made to retender the works to the Nominated Subcontractors, the Client’s Project Director decided to make additional reductions to the depth of the asphalt layer, this time, down to 50 millimeters. The result is a reduction in serviceable pavement life to a mere two years, plus or minus. Based on the above, a cost savings of about 15% resulted in a 95% loss in pavement life.

Some savings, huh? In the States, the trend is to provide projected pavement lifespans of greater than twenty years. In fact, the most recent sales technique by the asphalt suppliers is that, with proper design and strategic maintenance, their new pavements can last about forever. Certainly, the savings in regular reconstruction costs from now until forever would more than offset a small increase in initial construction cost. But money has something to do with this decision as well.

The reduction in pavement thickness on this highway made the dailies headlines briefly, spurred by various rants from the head of one of the local Chambers of Commerce. The gist of these rants was that the pavement thickness would be reduced significantly. The ranter was too little informed to understand the drastic reduction in pavement life caused by this, and only surmised that strength would be reduced proportionally with the thickness of the asphalt surfacing. Furthermore, the Client never released the original report showing the 150 millimeter design (I keep the office copy of this report in a secret place), so the initial reduction is not widely distributed public knowledge.

This may be the most maddening aspect of this entire assignment. That no matter how we work to maintain quality materials and workmanship, our efforts are sabotaged.

And by the Client, no less.

Hank reminds me on occasion, “We are only installers.”

As such, our responsibility would end once we made recommendation to the Client that they were making another large mistake. After that, our job is to build the road as best as we can.

What accelerates the decline of the roadway even further is the lack of any sort of enforceable vehicle weight restrictions. Too often, I see Contractors haul trucks outfitted with “cheater boards” (wooden rails extended above the top of the dump body) and then filled to a point where the angle of repose of the hauled material defines the load limits. In this case, axle loads are probably twice what they should be, which causes considerably more than twice the damage to this now fragile pavement.

I used to bitch to the Contractors about this, basing my argument on the Contract clause that requires them to obey the law. I would accompany this with veiled threats of backcharging them for repairs based upon theoretical damage caused by their overloaded vehicles. Eventually, someone was kind enough to inform me that the load limit law has not been revised since the 1930’s, and that today’s dump truck, even when deadheading, weighs in excess of the legal limit.

Ah, well. I am reminded of yet another Wailer lyric, simply “don’ worry ‘bout a t’ing, cuz ev’ry likkle t’ing gonna be alright.”