3 Answers

HI    THE CIRCUMFERANCE OF A CIRCLE IS  Pi x D  =  22/7 X 4 KEEP YOUR DIMENSIONS TO FT AS ITS EASIER

THEREFORE THE TOTAL VOLUME OF YOUR PIPE IS   22/7 X 4 X 1/3 X 20 = 84 cu ft approx

DEPENDING ON YOUR CONCRETE PIPE MIX SAY  150 lbs per cu ft

THIS GIVES   APPROX  12600LBS  = APPROX 6 IMP TONS

Concrete, Asphalt 140 pounds/cubic foot
Concrete, Gravel 150 pounds/cubic foot
Concrete, Limestone w/Portland 148 pounds/cubic foot

AS COLLEEN SUGESTS YOU WOULD BE BEST CONTACTING A MANUFACTURER AS THERE ARE VARIOUS TYPES OF PIPE AVAILABLE EG STANDARD, REINFORCED, LIGTWEIGHT ETC

HOPE THIS GIVES YOU SOME IDEA ANYWAY

MONDEOMAN

You would need to contact a company the sells them. We are general questions and answers and do not have access to this kind of information. 

12,150# more or less

3.07± cy @ 4,000 per Cy