Pavements? What’s the Difference?

There are three pavement types: Flexible – Asphalt concrete Rigid – Portland cement concrete Interlocking pavers – Stone, brick, or blocks But there are seemingly infinite variations of each. Flexible: The black stuff is asphalt concrete (left photo), also called hot-mix asphalt concrete. In some states or regions, it is […]

Portland Cement Concrete

Portland cement concrete (PCC) is primarily a composition of Portland cement, water, rock, and sand.  Portland cement is manufactured by grinding limestone, iron ore and/or fly ash into a powder and feeding into a rotary kiln at 2,700 degrees Fahrenheit. Not unlike the residue of a coal furnace, clinkers are […]

How Does Asphalt Get Made?

Producing hot mix asphalt concrete is an energy intensive process involving heating aggregate up to 435 degrees F, then mixing in asphalt cement and recycled materials. Typical recyclables are asphalt concrete removed from older pavements & garbage, asphalt shingles, plastic and glass.     So, the plant site shown has a stockpile of aggregate […]

Miscellaneous: Vehicle Barrier

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, […]

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 […]

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 […]