Asphalt vs. Concrete

My name is EE and I am an Aerospace Engineering student at the University of Texas at Austin. I am doing a feasibility study for a civil engineering technical communication class. I am comparing the use of concrete and asphalt for the reconstruction of a tennis court. I have discovered that the soil on which the reconstruction is to take place is very expansive(35% ferris soil).

I was wondering if you could answer a few questions to help my comparison?

1. Can you estimate the average life expectancy of a concrete tennis court under normal conditions? How about under soil shifting conditions?

2. Can you provide me with a rough cost estimate for a concrete or asphalt tennis court?

3. Would you expect a concrete court or an asphalt court to perform better under soil shifting conditions? why?

4. Have you ever encountered a similar situation, what decision was made? why?

5. Can soil swelling be combated by certain construction techniques?

6. What type of concrete would you recommend for a tennis court?

7. Could the type of concrete be changed in order to decrease the likely hood of it cracking in soil expansion conditions?

Thanks a whole bunch for your time.
width="450">Most of your questions require more time and space than I can provide here, but I will try to give you some guidelines and direction:

1. I don't. I doubt that anyone can do it accurately. Usually the main issue with asphalt erosion is water and traffic load. From economical standpoint it is common to use 15 years for asphalt pavement (not tennis courts) after which you need to either redo it, resurface, or replace). Serious soil shifting could cause the court to be unusable after a few months by creating cracks, bumps, and uneven surface. Asphalt has no resistance to these stresses.

2. No. That depends on market conditions. Tennis courts are very specialized work and will require a premium over normal pavement costs.

3. Depends. Concrete can be reinforced so it does not crack. Asphalt will flex and move with the soils. If done correctly, concrete (reinforced or post tensioned) will outlast asphalt without maintenance or damage by a factor of 3-4. However, you can expect the cost to probably be higher by similar factor. A lot also depends on soil preparation, proper base, proper compaction, pre-saturation...

4. Not with tennis courts.

5. Not easily. You should provide a properly graded and compacted base under the court and make arrangements to keep water content in soil constant. That can be done by either preventing water from getting there, or by making sure that it is always saturated and fully expanded. The changes are what causes the damage.

6. Any good quality material will work. I would recommend using the conditions for concrete exposed to earth (maybe sulfates) - water/cement ratio of 0.45 and type V cement.

7. Only by providing reinforcing, preferably post tension. A post-tensioned court will be more expensive, but will be the only way to assure performance.

You are welcome 

 

 width="450">Thanks for your quick response. You are very helpful. If you don't mind my partner and I would like to list you as a reference in our evaluation.