"Concrete has to be mixed with water in the proper proportions in order to be successful. If you use too much water, than the concrete becomes runny and won't set up properly. If you use too little water, the concrete won't spread and will clump. Concrete that needs to be mixed with air as well to allow for expansion and contraction. Be aware of the air temperature when getting ready to pour
. concrete.http://www.cement.org/basics/concretebasics_faqs.asp"