This guide describes the use of the European design standard Eurocode 2 to check deflection in concrete structures by calculation. The factors that affect deflection are listed and the most important ones are discussed: tensile strength, creep, elastic modulus, loading sequence, cracking and shrinkage curvature. Two methods for calculating deflection are presented: the rigorous method and a simplified method. In the simplified method, the effects of early age loading are not considered explicitly, but an allowance is made for their effect when calculating the cracking moment. Simplified creep factors are used and deflection from the curvature of the slab is approximated using a factor. It was concluded that the calculation of deflection in Eurocode 2 using the rigorous method is more advanced than the method used in BS 8110, but the method can still result in +15% to -30% error. PHASES AND STAGES. Example of simplified 4 approach crossroads, with 4 phases and 2 stages. Phase A southbound, Phase B westbound, Phase C northbound and Phase D eastbound. Note: it is conventional to notate phases clockwise round the junction. Interstage 1-2 has a 5 second interstage, made up of a 3 second amber and a 2 second red/amber. The timings for amber and red/ambers are obligatory, with a tolerance of plus or minus 250 milliseconds. The interstage 2-1 is shown with a 1 second all red, making it 6 seconds. The intergreens A-B, A-D, C-B and C-D are the same as the interstages 1-2 and the intergreens B-A, B-C, D-A, D-C are the same as the interstages 2-1. This document is Part 4 of Traffic Advisory Leaflet 1/06. It should be read in conjunction with Parts 1, 2 & 3. The Reference section is in Part 1. (Author/publisher)
Samenvatting