RCC21 sub-frame analysis is a spreadsheet program to calculate design moments for reinforced concrete elements such as slabs, beams and columns. The spread sheet program uses moment distribution method and considers critical load cases in the calculation of design moments.

It can analyze up to six spans and determines beam and column moments, and also slab moments as the case may be.

Generally for analysis to complete, you will be required to input span lengths, beam or slab section dimensions, dead and imposed loads, column height above and below beam section, column section dimensions and much more.