CIVL 1112 - Assignment #8

"If we knew what it was we were doing, it would not be called research, would it?"  -  Albert Einstein (1879 - 1955)

Objective

The purpose of this assignment is twofold: first, to continue to develop your engineering spreadsheet skills; and second, to develop a complete analysis tool for your reinforced concrete beam project. Basically, this spreadsheet will combine your work from the ACI mix design (Assignment #6) and rectangular reinforced concrete beam (Assignment #7) with an estimate of the reinforced beam cost to predict a cost-adjusted strength-to-weight ratio (ASWR).

Part 1: Compute the Adjusted SWR for each beam from the Week 1 data. Average the results for each beam type (the set of beams with no reinforcement, 1 rebar, 2 rebar and 3 rebars) and plot the average ASWR as a function of the number of reinforcing bars.

Part 2: Develop a spreadsheet to predict the ASWR of a rectangular reinforced concrete beams in bending without considering shear reinforcement in the beam weight or beam cost. Use the spreadsheet to predict the ASWR  for the reinforced concrete beam displayed in the sample interface sheets.

• Input parameters should include: the height and length of the beam, the amount of reinforcement material (both tension and shear), the compressive strength of the concrete, the yield stress of the reinforcement, the unit weight of the concrete, the minimum concrete cover for the reinforcement, the minimum spacing between rebars, and the shear reinforcement spacing.
   

• From these inputs, you should compute the minimum width of the beam b, the depth to the center of the reinforcement d, the area of steel in tension A_s, the area of steel is shear A_v, the b₁ constant, The height of the Whitney stress block a, and depth to the neutral axis c, the c/d, the predicted  strength in tension, shear, and compress, the weight of the beam, the SWR, the cost of a single beam, and the ASWR.  
  
  

• In addition, check to see if the reinforcement yields before the concrete crushes (see class notes) and that the reinforcing bars fit into the proposed beam. 
  
  

• Compute the cost of the reinforced concrete beam on the "ACI Mix" sheet of your workbook. Values for the concrete compressive strength, the dimensions of the beam, and the volume of steel are available from the "Rectangular Beam Analysis" sheet.