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. SIGNAL SEQUENCES. The signal sequence at junctions in GB is red, red +amber, green, amber, red. The standard period during which an amber signal is displayed is fixed at three seconds and the red + amber signal at two seconds (see TR 250022, “Specification for Traffic Signal Controller” for tolerances). The duration of the green signal will depend on the method of control. See later references to “vehicle actuation”, “MOVA”, “UTC”, “SCOOT” and “linking”. Traffic signal controllers in GB make use of “stages” and “phases”. Controllers select stages. The timings and demands are, however, phase based. The controller philosophy is designed to select the duration and the order of the stages to give right-of-way to phases in an optimum manner. This document is Part 2 of Traffic Advisory Leaflet 1/06. It should be read in conjunction with Parts 1, 3 & 4. The Reference section is in Part 1. (Author/publisher)
Samenvatting