We had a new asphalt driveway installed nearly one year ago in New England. Today in 75 degree sunny weather we sat outside in plastic Adirondack chair for about 45 minutes. When we got up we noticed the chairs made big indents in the asphalt. Is this normal for a a year-old driveway?
When I built my 1st home 40+ years ago I noticed that my neighbor had a beautiful, smooth, and very black asphalt driveway. I remarked to him that it looked great. He said it looks great but has the same problem that you are describing, being very soft on a hot day. I inquired about this problem with the asphalt driveway guy and he said that an asphalt driveway can be black, beautiful, and soft or I can be "kind of black" with some gray stones showing and very hard. I chose the latter and found that it was almost indestructible. He had to replace his driveway in a few years and opted for one like mine.
Small chair feet with an adult in the chair put a high loading on the asphalt.
Given the choice I would rather an elephant stand on my foot than a lady in stiletto heels. Good reason that stiletto heels were banned from wood dance floors...
Consider chairs with larger feet or use pads under each chair foot.
It is possible of course that the mix may have been incorrect but i don't have any issue with mine and I have used a trolley jack on it.
"Asphalt" is about as definitive as "rock"; that is- not definitive. Asphalt is a blend of asphaltenes, oils, and resins.Depending on the ratios and the properties of the individual components AND the amount and type of aggregate, the results can be about anything. Traditional bituminous concrete ( aka -asphalt) contains 6% asphalt blend ( by weight) of the mix .My guess is the supplier added extra oil to make a cheaper product . The lower strength would ,hopefully, not be noticed because it is only a driveway. There is nothing you can do except not put chairs on it or replace it. Look at the good side, you don't have "alligatoring " or other more serious problems. There is a reason that state highway departments have whole groups testing and verifying asphalt properties for road construction.