AC
AC turns up in 2 fields: electrotechnology, asphalt. Here is what it means to the people in each one.
AC in electrotechnology
The standard abbreviation for alternating current.
Alternating current, the standard format for generating and transmitting electrical power on the grid. In AC systems, the flow of electric charge periodically reverses direction, allowing voltage to be easily stepped up or down using transformers.
"The inverter converts the DC from the solar array into AC for the grid."
AC in asphalt
Asphalt cement: the binder itself, and in pavement design talk, shorthand for the asphalt concrete layer.
Asphalt cement, the North American plant and lab name for paving binder: AC content means binder percent, and the binder tank is the AC tank. Viscosity-graded binders carry it in their names, such as AC-10 and AC-20, rated by absolute viscosity at 60 C, with AC-20 at about 2,000 poises. On drawings and in pavement design, AC can also mean asphalt concrete, the finished mix layer, so context decides which one is meant.
"Burn came back at 5.2 percent AC, JMF says 5.4, tell the plant to bump the oil a tenth or two."