FRP reinforcement in RC structures

fib Bulletin 40 deals mainly with the use of FRP bars as internal reinforcement for concrete structures. The background of the main physical and mechanical properties of FRP reinforcing bars is presented, with special emphasis on durability aspects. For each of the typical ultimate and serviceability limit states, the basic mechanical model is given, followed by different design models according to existing codes or design guidelines

Testing Sleeping Bags According to EN 13537:2002: Details That Make the Difference

The European Standard on sleeping bag requirements (EN 13537:2002) describes a procedure to determine environmental temperature limits for safe usage of sleeping bags regarding their thermal insulation. However, there are several possible sources of error related to this procedure. The main aim of this work was to determine the influence of the various measuring parameters on the acuity of the respective parameters in order to judge the requirements. The results indicated that air velocity, mattress insulation and time between unpacking the bag and measurement had a significant impact on the result, with a difference of up to 5–15% in thermal insulation between minimum and maximum allowable parameter levels. On the other hand, manikin weight, thickness of the artificial ground and presence of a face mask were found to have a negligible influence. The article also discusses more general aspects of the standard including the calculation methods used

The influence of sustained stress on the durability of GFRP bars embedded in concrete

A new test equipment has been created to study the combined effect of environmental exposure and external stress on the durability of a GFRP (E-Glass/Vinyl ester) rebar. GFRP specimens embedded in moisture-saturated concrete have been conditioned at two temperatures and at two levels of sustained tensile stress (5% and 25% of the ultimate tensile strength). According to the preliminary results, stress levels up to 25% of the original tensile strength do not appear to have a negative influence on the durability of GFRP bars embedded in concrete