Civil Engineering/Buildings

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Expert: - 1/4/2011


Question
1. Remind me the different mixes for different concrete classes and their strength.
2. If given the spacing(say "y" meters from truss to truss) of trusses in for a house and all members of the truss are 50mm x 100mm, what is the formula for calculation the depth of purlins

Answer
Hi Bernard,

1. This website will help you with full details of concrete mix design:

http://concrete.union.edu/general.htm

The usual grades of concrete are 10, 15 and 20 N/mm2 for mass concrete and 25, 30, 35, 40, etc N/mm2 for structural rinforced concrete

2. The sizes of the truss members are irrelavant to design of the purlins- what matters is the span and spacing of the purlins and the loading (type/angle of roof material, plus wind/snow loading). The guide from this website is useful:

http://www.ribaproductselector.com/Docs/0/17250/external/COL2017250.pdf?ac=  

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Arshad Khan

Expertise

I can answer any questions to do with civil and structural engineering consultancy and construction industry in East Africa and the Middle East, and specifically with the analysis and design of reinforced concrete structures. My particular expertise is in the aseismic design and optimisation of tall buildings.

Experience

Employment history: 36 years in Construction and consultancy in the UK, Kenya, Tanzania, Uganda, Ethiopia, Eritrea, South Africa, Somalia, Zambia, Austria, Bahrain, Kuwait, Doha and the U.A.E.

Organizations
.Fellow of Institution of Structural Engineers (UK) .Fellow of Institution of Civil Engineers(UK) .Member of the Institution of Engineers, Kenya .Registered Engineer, ERB, Kenya .Member of the Architectural Association of Kenya (Engineers Chapter) .Chartered Engineer (UK)

Publications
•1984: International Conference on the Art and Practice of Structural Design, London •1994: 3rd Int. Kerensky Conference in Structural Engineering, Singapore •2008: International Conference on High-Rise Towers, Abu Dhabi

Education/Credentials
BSc, 1st Class Hons, in Building Engineering, University of Bath, UK MSc in Concrete Structures and Technology, University of London. Diploma of Imperial College, UK.

Awards and Honors
•Science Congress Special Award (for 2-seater Hovercraft - 1968) •Institution of Civil Engineers Award for outstanding performance at Bath University (1975) •Concrete Society Postgraduate study Bursary Award (1976) •Consular Representative for British High Commission, Nairobi. (1995 to 1998) •Examiner for Institution of Civil Engineers Professional Interviews, Nairobi. (1997 to 1998) •Branch Representative in Vienna for PI assessment for Inst. of Struct. Engrs. (1999 to date)

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