There are a lot of risks in construction. One problem is that once something is built it is around a long time. Consider asphalt. If it is a component of heavy fuel oil, it is purchased and used in a short time. If there are problems, they are obvious, almost immediately found and taken care of. If the asphalt is used in pavements, on the other hand, it is around for years, and can be subjected to tort suites throughout its lifetime. One area where legal actions have been used extensively is with gated communities. What happens is that a team of attorneys and civil engineers contact the managers of gated communities and arrange to inspect the facilities, even after many years from construction, then sue all the contractors for one problem or another, real or imaginary. What is supposed to take place is that all of the contractors are expected to bring their insurance agent to a meeting and settle, then the attorneys and gated community share in the settlement. The attorneys can get real testy if the contractors don’t immediately capitulate.

I have had experience as a consultant on the side of a paving contractor, in which we demonstrated that one does not have to submit to such extortion.

It was very interesting with the projects with which I was involved that the engineering consultants on the attorney’s team did not even know the vocabulary of the field of asphalt technology nor were they to truly able to identify causes of stress or determine which contractor was at fault. In one case they were complaining that a product that had been applied years before had been out of specification. Unfortunately they were comparing that product to a specification of a completely different product but didn’t know enough about asphalt products to be able to recognize their error. Once I finally got that across to the attorney in a deposition, he immediately shut down the deposition.

The lesson to the contractor is to confront the attorneys with personnel who are truly experts in the field; not those with only limited academic training, but those with true experience with the field. While there can be problems that have occurred during construction that need to be addressed, problems of aging and lack of maintenance are not the contractor’s problem no matter how strong attorneys and unknowledgeable “experts” may make demands.

The lesson for the managers of gated communities is to engage someone who has real practical knowledge in the various areas of technology without the intervention of attorneys. It is very important that a maintenance program includes sealing the pavements to prevent oxidation and water damage which can greatly affect the life of a pavement.

In other areas of construction damage can be avoided. As an example, waterproofing stucco walls with certain excellent products can avoid water damage and mold problems.

And finally, a lesson for those writing the specification for asphalt paving in gated communities is to be sure that the paving specification requires that the paving mix be tested for water resistance.

Robert L. Dunning,,



What are asphaltenes? While often discussions about the composition of asphalt will define asphaltenes in chemical terms, the basic definition is that asphaltenes are material in asphalt that is insoluble in certain solvents. For some, asphaltenes appear to be something that is in the way that must be tolerated. That is far from the truth. First, as mentioned above, the definition of asphaltenes is simply material insoluble in either pentane, hexane, heptan or octane, depending on the method used. Often the compositions are described as being saturates, aromatics, polar materials and asphaltenes. In fact asphaltenes might be considered to be simply the part of polar materials that are insoluble in some arbitrary solvent. If an asphaltenes-free asphalt is exposed to light, new asphaltenes will be formed. In fact pictures have been taken using asphaltenes-free asphalt as the “film”. Upon exposure to light a picture is formed.

What do they do? Asphaltenes have three important functions: 1) a bodying agent; 2) forming a complex structure that aids in performance in conjunction with the other polar materials; 3) and helps to reduce hardening with time.

Bodying agent. There was an asphalt a number of years ago that was essentially asphaltenes free. It acted almost like lubricating oil and was such a problem that the agencies insisted that it be blended with different more suitable asphalt. Normally once a hot mix is made, and cools, a gel like structure is formed that aids in the setting of a hot mix. With some asphalts there is a setting problem because the formation of that structure is slow or weak and mixes made with them are tender. Other asphalts result in hot mixes that set very well and are not considered to be tender. At one time California DOT had a test using what they called the cohesiograph that measured tenderness.

Performance.  Tender mixes tend to rut easier and to be easily marred from power steering. If the aggregate gradation in the hot mix has too much sand, the mix will be very hard to compact. If the asphaltenes bodies up the mix well, compaction will go well even with oversanded mixes.

Aging. When the relationship between the polar-asphaltenes is optimum, oxidation will be controlled. In the asphalt “micelles” (a term coined by Dr. Claine Petersen, one of the foremost asphalt scientist in the world in my opinion) are formed such that oxidation is restricted for the material in the micelle so that the rate of oxidation decreases with time. With asphalts in which the asphaltenes are too well dissolved and micelles do not form, the rate of oxidation continues resulting in very hard asphalts in the pavement in a relatively short time. We have run across some cracked pavements that were not very old but the asphalt was very badly oxidized. The asphalt used was from a crude oil in which the micelles do not occur.

Robert L. Dunning,,


Petroleum Sciences, Inc.


Petroleum Sciences, Inc. in Spokane, Washington has asphalt laboratory equipment for sale. They are shifting their emphasis toward asphalt emulsion research and testing, seal coat mix designs and testing, seminars and booklet’s on asphalt technology, forensics and consulting. The equipment available is shown below. All sales are FOB Spokane, WA.


Mix Design Equipment

Gyratory Compactor,  2006 Reinhard, portable. Newly calibrated and in excellent shape.

plus several molds and computer.                                                                                    $17,830

Dispatch Oven, 2006 with Extra Shelf                                                                                   4,500

Remaining equipment for running S-Value, R-Value, Marshall Stability

Immersion compression stripping test, and AASHTO T 283 stripping test          15,000

Other Equipment:

Trailer mounted coring machine which uses nitrogen to cool cores so that they are dry.

Including 6” and 4”(ID) core barrels                                                                                    12,500

PAV apparatus, very little use                                                                                                 11,000

One Silverton shearing disperser, not priced yet.

Possibly Myer two shaft mixer for mastics, not priced yet.

2 Solvent Recoverers, not priced yet.,, 509-220-1360