Here we answer some of the topics which are most frequently asked by our readers – some of whom are members of the public, some business owners and some industry professionals.
GENERAL QUESTIONS
HOW CAN I FIND A CALIFORNIA PAVING PROFESSIONAL CONTRACTOR IN MY AREA?
We hold a comprehensive list of all the paving professionals in the state of California.
The list is divided into two groups, regular members and associates.
All the contact information is provided, for both of the groups.
WHAT IS THE DIFFERENCE BETWEEN ASPHALT AND TAR?
Although they both look the same, tar and asphalt are made from different things entirely.
Tar, as the name implies, derives from coal. It is mixed with bits of broken up stone. Whereas asphalt originates from petroleum oil.
WHAT IS HOT MIX ASPHALT?
Hot Mix Asphalt is a combination of gravel, stone and sand (95%) which is held in place by asphalt cement.
This in turn, is a heated aggregate which is mixed at the HMA facility. It is then sent to paving sites and put into place with heavy rollers.
HMA allows traffic to use the paved surface just as soon as it has cooled down.
WHAT IS SUPERPAVE?
Superpave is a name given to the outcome of the research into asphalt of the Strategic Highway Research Program held between 1987 and 1993 (SHRP).
It is a mixture of asphalt binder, a HMA method of mix and HMA performance models.
WHAT IS STONE MATRIX ASPHALT?
Stone Matrix Asphalt (SMA) is HMA which is gap graded. It has been designed to combat rutting and has been rendered hardwearing by its structural makeup.
All the aggregates are in stone on stone contact with each other. This makes it much more resilient to rutting.
SMA is usually more expensive than HMA because of its hardwearing aggregates and higher asphalt levels.
Used correctly, it is a very cost effective solution to rutting and other problems with durability.
It has been used in the States since the year 1990.
WHAT IS ASPHALT TREATED BASE
Asphalt Treated Base or ATB is a dense HMA which has a lower asphalt content and a wide gradation band. It is meant to be used as a base course with stabilizing qualities. It is not as expensive as most HMAs because the aggregates are less costly and there is a lower proportion of asphalt binder.
The advantages of ATB include its water resistance. This makes the pavements it is used on withstand flooding better.
Also, it is at least three times stronger than base material which has not been treated.