Structures 3 Midterm Winter 2025 Study Notes

Structures 3 Midterm Winter 2025

Problem Overview

• A building owner intends to repurpose a recently purchased facility into a factory.

• The floor of the second storey is framed with concrete beams.

• The task involves determining the maximum beam spacing (tributary width) based on the loading conditions provided, specifically for the new factory configuration.

Loading Conditions

• The following loading conditions are defined for the scenario:

  • Service Dead Load (SD): 20 kN

  • Service Live Load (SL): 35 kN

  • Additional unit loading (udl):

  • Service Dead Load (SD): 2.2 kPa

  • Service Live Load (SL): Library study room

• The loading pattern for the second floor is detailed in the accompanying diagrams (not shown here).

Calculation Requirements

• The objective is to find the maximum beam spacing that can support the combined loading.

• It is specified that the answer should be rounded to one decimal place.

Notes for Calculation

1. Concrete Specifications:

   • 25 MPa Concrete

   • Designed for exterior exposure

   • Maximum aggregate size is 20 mm

2. Structural Considerations:

   • Self-weight of the concrete beams must be considered in the calculation, as it contributes to the overall dead load.

Example Calculations (Assumptions made for illustration)

• If the total uniform load is calculated by adding the dead and live load:
  $Total\, Load = SD + SL = 20 \, kN + 35 \, kN = 55 \, kN$

• The area of the beam can be determined by considering the unit load and dimensions:
  $Area = Load \, (in \, kN) / Unit \, Load \, (in \, kPa)$

• For example, if the unit loading is calculated:

  • For Service Dead Load:
    $UDL_{SD} = Service \, Dead \, Load imes \, ext{Area}$

  • For Service Live Load:
    $UDL_{SL} = Service \, Live \, Load imes \, ext{Area}$

• The combined loading configuration would need to ensure that the shear and moments within the beams are manageable based on this calculated load.

Conclusion

• The maximum beam spacing calculation needs to consider both dead and live loads, ensuring it is structurally sound under proposed conditions. Ensure to finalize the calculations and rounding thoroughly for submission in accordance with guidelines provided.