EGB375 · Design of Concrete Structures
The Complete Exam Bible · S1 2027Design of Concrete Structures
EGB375 Design of Concrete Structures is a third-year civil-engineering unit at Queensland University of Technology, worth 12 credit points, taught in the Faculty of Engineering and graded on GPA (QUT's 7-point grade-point average). It is the reinforced- and prestressed-concrete design unit of the program, governed throughout by the Australian Standard AS3600-2018. It carries you from the equivalent rectangular stress block through the ultimate moment and shear capacity of beams, then serviceability, slabs, columns and isolated footings, always as a design calculation rather than pure theory. This free guide mirrors how EGB375 is assessed at Queensland University of Technology and works every element end to end for the closed-book final that decides half the unit mark.
What EGB375 covers
Twelve chapters walk EGB375 from the equivalent stress block through reinforced- and prestressed-concrete flexure, shear, serviceability, slabs, columns and footings — every element worked to AS3600-2018 for the QUT final.
How EGB375 is assessed
| Component | Weight | Format |
|---|---|---|
| Self-assessed Homework Reflection | 10% | Single end-of-semester self-assessment form (student awards own grade 1-10 across ~11 weekly HW problems + 100-word justification), Week 13 |
| Design Project — Oral Poster Presentation | 15% | Group of 4, out of 15 marks (10 group presentation + 5 individual Q&A), Week 7 |
| Design Project — Written Report | 25% | Individual written report out of 25 marks, Week 11 |
| Final Exam | 50% | Closed-book, paper-based, out of 100, QUT Central Examinations; five A4 double-sided student-prepared note sheets permitted (handwritten, typed, or a mix); duration not stated |
Ultimate moment capacity of a singly reinforced beam (AS3600-2018)
- +2Stress-block factors (grade-dependent): alpha2 = 0.85 - 0.0015(32) = 0.802; gamma = 0.97 - 0.0025(32) = 0.89 (both >= 0.67, so valid).
- +1Steel tension (steel assumed yielded): T = Ast.fsy = 930 x 500 = 465 000 N = 465 kN.
- +2Neutral axis from horizontal equilibrium C = T: dn = T / (alpha2.f'c.gamma.b) = 465 000 / (0.802 x 32 x 0.89 x 250) = 465 000 / 5710 = 81.4 mm.
- +2Ductility gate: kuo = dn/do = 81.4/450 = 0.181 <= 0.36 (ductile); strain check eps_st = 0.003(450 - 81.4)/81.4 = 0.0136 >= 0.0025, so the steel has yielded and T = Ast.fsy holds.
- +1Lever arm of the internal couple: Z = d - gamma.dn/2 = 450 - 0.89 x 81.4/2 = 450 - 36.2 = 413.8 mm.
- +1Moment capacity: Mu = T.Z = 465 000 N x 413.8 mm = 1.924 x 10^8 N.mm = 192.4 kN.m.
- +1Design capacity for bending (phi = 0.85): phi.Mu = 0.85 x 192.4 = 163.5 kN.m, to be compared with the factored moment M*.
Key terms
- Equivalent rectangular stress block
- The AS3600 idealisation of the concrete compression zone as a uniform stress alpha2.f'c acting over a depth gamma.dn from the compression face, replacing the true curved stress distribution.
- alpha2 and gamma
- Grade-dependent stress-block factors: alpha2 = 0.85 - 0.0015 f'c >= 0.67 and gamma = 0.97 - 0.0025 f'c >= 0.67 (e.g. 0.802 and 0.89 at f'c = 32 MPa).
- Neutral axis depth dn
- The depth from the compression face to the level of zero strain, found from horizontal equilibrium C = T; dn = Ast.fsy / (alpha2.f'c.gamma.b) for a singly reinforced section.
- Lever arm Z
- The distance between the concrete compression resultant and the steel tension resultant, Z = d - gamma.dn/2; the moment capacity is the couple T.Z.
- Ductility ratio kuo
- kuo = dn/do; AS3600 requires kuo <= 0.36 so the section is under-reinforced and the steel yields (warns) before the concrete crushes.
- Capacity reduction factor phi
- The strength-reduction factor applied to nominal capacity: phi = 0.85 for bending, 0.75 for shear with N-type fitments, 0.7 for footing punching, 0.6 (0.65 short) for column compression.
- Prestress ultimate stress sigma_pu
- The tendon stress at ultimate, sigma_pu = fpb(1 - k1.k2/gamma), used with the neutral-axis depth to find the prestressed moment capacity Mu.
- Shear depth dv
- The effective shear (lever-arm) depth, dv = max(0.72D, 0.9d), at which V* and M* are taken and used in the MCFT-based shear equations.
- Strut angle theta_v
- The compression-strut inclination in the MCFT shear model, theta_v = 29 + 7000.eps_x, where eps_x is the mid-depth longitudinal strain.
- Effective second moment Ief
- The tension-stiffening inertia used for deflection, Ief = Icr / [1 - (1 - Icr/Ig)(Mcr/M*)^2] <= Ig, interpolating between cracked and gross behaviour.
- Interaction diagram
- The column strength envelope in (M, N) space defined by Points A (squash), B (decompression), C (balanced, dn = 0.545d) and D (pure bending); the design point (M*, N*) must lie inside the factored curve.
- Moment magnifier delta_b
- The slender-column factor delta_b = km/(1 - N*/Nc) >= 1.0 that amplifies the design moment to Mmax = delta_b.M2* once Le/r exceeds the short-column limit.
- Punching shear
- The two-way shear check on a footing or slab around a column, at a critical perimeter u a distance dom/2 from the face; require V*punch <= phi.Vuo with fcv <= 0.34.sqrt(f'c).
- AS3600-2018
- The Australian Standard for Concrete Structures that governs every design factor, capacity equation and detailing rule examined in EGB375.
EGB375 FAQ
Can AI help me study EGB375?
Yes. Sia is an AI study tutor that explains EGB375 topics step by step, so you can ask it to walk through the C = T to dn to ductility to Z to Mu flexure workflow, the MCFT shear procedure, or a column interaction check, and have it show each AS3600 step and unit conversion. It is built to help you understand and rehearse the method on your own practice sections, not to hand you homework or exam answers, and no tool can promise a particular mark or grade.
Where can I find past exam papers or practice for EGB375?
Start inside Queensland University of Technology's own systems: previous exam problems, tutorial questions and homework solutions are posted on the EGB375 Canvas site, and the free unit workbook is the primary practice source. This guide adds ten worked, exam-style design problems with fresh numbers so you can practise the same skills without reproducing any real paper; use Sia to check your reasoning on each step.
What can Sia do that a textbook can't?
A textbook shows one worked example and then stops; Sia responds to your specific working, so when your dn or your stress-block factor is off it can pinpoint the line and explain why, and it will re-explain a step as many times and as many ways as you need. It can generate a fresh practice section, walk the AS3600 check you are stuck on, and adapt to what you already know, all step by step and without ever promising an answer key or a grade.
Is EGB375 hard?
It is a design-calculation unit, so the challenge is procedural rather than abstract: you must apply the correct AS3600 factors and checks to each element and carry units cleanly, which rewards steady practice over memorisation. Students who build fluency with the flexure, shear and serviceability workflows and keep every calculation in N and mm tend to find it manageable.
Is the EGB375 exam open or closed book?
It is a closed-book, paper-based final scheduled by QUT Central Examinations, marked out of 100 and worth 50% of the unit. You may bring five A4 double-sided student-prepared note sheets, so it is not open-book and there is no official formula sheet; the duration is not stated in the unit materials, so confirm it on the QUT exam timetable.
What is examined in EGB375, and is there a hurdle?
The final is design-computation heavy: ultimate moment and shear capacity for reinforced and prestressed members, serviceability (cracking and deflection), slab, column and footing design, and reading shear-force and bending-moment diagrams, all to AS3600-2018. No hurdle is stated on any single component in the unit materials, but the 50% exam is the largest single piece of the mark, so confirm the current rules on Canvas and the unit outline.
What GPA do I need for a good grade in EGB375?
EGB375 is graded on GPA, Queensland University of Technology's 7-point grade-point average, and each grade maps to a band: grade 7 (High Distinction), grade 6 (Distinction), grade 5 (Credit) and grade 4 (Pass) - you need a 4 to pass. Your unit grade is built from the three assessment pieces (10% self-assessed homework reflection, 40% design project, 50% final exam), so a strong grade means scoring well on the design project and, above all, the 50% closed-book AS3600 final. Sia can help you target those bands compliantly: it explains each flexure, shear, serviceability, slab, column and footing workflow step by step so you build the fluency the exam rewards - it never guarantees a grade, and no tool can promise you a particular GPA.
How many credit points is EGB375 and what do I need to know first?
EGB375 is a 12-credit-point third-year civil-engineering unit at Queensland University of Technology. The unit materials do not list a specific prerequisite unit code, so treat the entry expectation as assumed knowledge rather than a named prerequisite: comfort with structural mechanics and analysis - drawing and reading shear-force and bending-moment diagrams for simply-supported and cantilever beams, and basic mechanics of materials - since EGB375 builds design methods on top of that (confirm the current prerequisites in the QUT unit outline). The unit runs on the Canvas LMS, where lectures, the free unit workbook, tutorial and homework problems and previous exam papers are posted. The closed-book final is scheduled in the QUT Central Examination period, with a revision/study week before it, so plan your final revision into that study week.
How to study for the exam
Treat EGB375 as a set of repeatable design workflows rather than a reading unit: for each element, learn the sequence once - recompute the stress-block factors, balance the forces (C = T or Cc + Cs = T), find the neutral axis, prove ductility (kuo <= 0.36), then apply phi and check adequacy - and practise it until it is automatic. Work every problem in newtons and millimetres and convert only at the end, because most lost marks are a wrong grade-dependent factor, a skipped ductility check, a mis-picked phi, or an N.mm to kN.m slip. Because the final is closed-book with five A4 double-sided note sheets, build those sheets as you revise: put the factors, one solved example per element (flexure, shear, serviceability, slab, column, footing) and the key AS3600 limits where you can find them fast, then rehearse the ten practice problems in this guide against the clock once you confirm the exam length on the QUT exam timetable. Use the QUT Central Examination period, with its revision/study week before the exam, as your dedicated window to consolidate those note sheets and work past exam papers and practice problems - the previous exam problems and tutorial and homework questions posted on Canvas are the best rehearsal for the real thing.
Your AI Engineering tutor for EGB375
Stuck on a hard EGB375 question? Sia is AskSia’s AI Engineering tutor — ask any EGB375 Design of Concrete Structures question and get a clear, step-by-step explanation grounded in how the course is actually taught and assessed. Read this whole study guide free, then take your hardest questions to Sia.
