Bending and axial force
In determining the resistance of sections in bending with axial force, in addition to the assumptions made for flexure above, the following assumptions are made:
- For sections in pure axial compression, the compressive strain in concrete should be limited to 0.00175, see Figure 8) below.
- For sections in pure flexure, the compressive strain in concrete should be limited to 0.0035, see Figure 7).
- For situations intermediate between these two conditions, the strain profile is defined by assuming that the strain is 0.00175 at half the depth of the section, see Figure 8b).
Figure 8: Strain diagrams for columns (valid for concrete up to class C50/60 from Eurocode 2)
Extract from How to Design Concrete Structures using Eurocode 2: Columns (page 37, figure 8)
The reinforcement for columns may be determined in two ways:
- Iteration on neutral axis depth, x (see Figure 7) such that Asreqd for bending = Asreqd for axial load.
- Column charts based on NEd/bhfck vs MEd/bh2fck and d2/h.
Figure 7: Stress block diagram for columns
Extract from How to Design Concrete Structures using Eurocode2: Columns (page 37, figure 7)
Axial forces are determined from analysis. Design moments must include for 1st order moments from analysis and for the effects of imperfections and, in the case of slender columns, for the effects of slenderness.
For more explanation see information on Columns
Gives likely structural options for a concrete frame, with useful points to note - written by engineers for engineers.
An all-you-need-to-know guide on the specification of sustainable concrete.
This guide sets out how concrete's attributes can be used to minimise CO2 emissions.
This guide focuses on concrete and masonry housing, and presents requirements for Part L1A of the Building Regulations.
Guidance on how concrete can be used to achieve credits under the latest version of BREEAM NC:2014.
£30.00 + VAT
This publication summarises the material used in the design of reinforced and prestressed concrete bridges using Eurocode 2
This guide focuses on the use of concrete at Coin Street Neighbourhood Centre and its part in creating a low energy building.
£55.00 + VAT
This publication assists engineers in understanding the common challenges of building tall.
This document provides information on the material and resource efficiency of concrete and masonry.
This publication looks at innovation and the learning and proven performance that we can’t afford to leave behind.