Tip: Concrete
Concrete is a strong, durable material when it is properly prepared, but while it is being produced it is perishable and difficult to transport. It must be mixed on site or else prepared by a service that specializes in delivery.The delivery must be carefully timed.
The strength and durability of concrete depends on critical chemical reactions that have to be monitored from initial mixing to finishing. There are hundreds of different mix designs for many uses and design specifications, including different strengths and colors.
-- Tips courtesy of HomeAdvisor.com