I was at dinner (outside because of Covid). The restaurant had a unique barrier to protect the dining tent. It is a portable vehicle barrier from Pitagone and distributed by ARX Perimeters. It is a product from Belgium and appears to be bad ass.There is no anchoring involved. An intruding vehicle hits the barrier, […]
Author Archive: Thomas Zimmer
Working on the Highway, Laying Down the Blacktop: Asphalt Concrete Paving
Hot mix asphalt concrete (abbreviated as HMA or HMAC) is a thermoplastic mixture of asphalt cement, rock and sand. In some states the mixture is called bituminous concrete. The earliest asphalt roads were called Macadam, after a Scottish engineer, John McAdam. He created a road building method in the early 1800s […]
Pavement Rating: The Heart of It All
The Pavement Condition Index (PCI) is the most important element of determining pavement conditions. It is at the heart of the Zimmer approach to managing pavements. The PCI was developed at the Corps of Engineer’s Construction Engineering Research Laboratory (CERL) in Champaign, Illinois by my friends, Mo Shahin, PhD. and […]
Pavement Rating: Moving from a Subjective to an Objective Approach
What we mean by a subjective approach is a property manager will rate or prioritize pavement conditions visually or with a seat of the pants approach. Rating is made by what looks worse or how uncomfortable the ride is. With pavement management, a subjective approach can work on a single, small property […]
Around n’ Round We Go: Asphalt Concrete Recycling/Paving Process
Below is a really good figure of the equipment used in the surface milling/recycling/paving process. It was produced by The Wirtgen Group. They manufacture milling machines, crushers, hot mix asphalt plants, pavers, and compactors, like a vertically integrated conglomerate. Interestingly, Wirtgen is a corporate subsidiary of the John Deere Company. […]
Pavement Patching: Throw and Go
A common approach to repairing a pavement pothole is to fill the void with asphalt concrete. If there are only a few potholes, a few bags of cold patch material from the local builder’s supply store can be use to fill the holes. Here are some tips that will make […]
RUH ROH – Time to Call the Mystery Machine and Get This Dimple Fixed!
This cute dimple in the pavement is a sign of a future maintenance problem so be sure to keep an eye out and for it to worsen. Experience tells us that a cavity has formed under the pavement surface layer, likely because subsurface water is carrying fine soil and rock […]
Tearing Up the Highway Like a Big Old Dinosaur
If you know me, you know I’ll take any opportunity to work a Bruce lyric into a post. But, unlike the song, a Cadillac isn’t tearing up the highway. The machine used is called a rotomill. In the photograph, it is working overnight to remove a portion of a parking lot asphalt concrete […]
The First Smart Road?
Roads have been constructed for centuries, but have intelligent roads been around for as long? A good case can be made by examining the above photograph. The roadway is found in the ancient Roman city of Pompeii. The Romans were on to something here and you will see similar approaches used in […]
The 2,000-Year-Old Road
It has been noted that ancient Roman roads are still intact after 2,000 years but nowadays, it seems our roads are in constant need of repair. Why is that? There are many reasons for short performance lives, but for now, we will focus on the Roman road cross section. After comparing […]