Q1       A C25/30 reinforced concrete flooring system 160mm thick in an office block

involve slabs spanning continuously and cast in-situ with a number of 300mm wide and 340mm deep downstand beams at 5m centres.  These beams span in the             perpendicular direction continuously and monolithically over a series of columns at 10m centres. This pattern is repeated over a large plan area on a 5m x 10m grid. The total factored D+L load, including self-weight is estimated to be 10kN/m2 .

beams, determine the BMD for this beam in a typical internal area.                   [5]

(b) Determine the beam reinforcement required at a typical internal mid-span       [10]

(c) Determine whether the beam width is sufficient to carry the moment at a typical   internal column support. Propose a solution and design the reinforcement.        [5]

(d) Draw your final beam layout, sizes and rebar layout as designed above.  Show key beam cross-sections to detail your rebar pattern. Explain clearly in words and        through sketches the consequences of changes in the dimensions to part c) on your calculations in part b). (NB: You do not need to re-calculate part b)).                [5]

Q2       A series of 7m simply-supported C25/30 RC Beams are required to withstand a total

factored design UDL including self weight of 200kN/m. Bending calculations have     sized the beams as b=300mm and h= 700mm with a tension reinforcement of 4H25     bars at an effective depth = 650mm throughout the entire span. The beams will be pre- cast off site to sit on end supports.

minimum shear.                                                                                                         [15]

(b) Draw a neat scaled sketch of the practical rebar layout in elevation and cross-section

showing where the shear-link spacing changes.                                                          [5]

(c) Describe briefly utilising sketches the concept of “punching shear” and what checks   are done in flat slab construction to ensure that punching shear is not a problem.     [5]

Q3       A city centre office block built in the 1960s requires significant refurbishment in

order to bring it in line with new energy efficiency and low carbon design criteria. It comprises 425mm x 370mm C25/30 reinforced concrete short columns containing   4H32 corner bars and 8mm links with a 40mm cover to the links from the column    edges.

(b)       Using the same axial load, calculate the maximum ULS minor-axis moment this

column can withstand.                                                                                     [5]

(c)       Determine whether a reduced axial load of 1800kN would allow both of these above moments to be carried bi-axially

[10]

Q4       A structural steelwork framed factory roof contains a 7m spanning simply supported

beam. A heavy piece of machinery weighing 90kN (fully factored) is to be located on this roof but it could be located at various points along the top flange of the beam       namely at either the 1m, 2m, 3.5m, or 4m points. The construction will provide          effective lateral restraint at the two end support points and additionally as described   below. (NB: Please ignore the beam self weight in all the calculations.)

(c)       Describe with sketches the effect that lateral torsional buckling has on a beam. In addition discuss the types of construction methods that ensure that the Mc    value can be used in determining Bending Moment capacity.                        [5]