EFFECT OF LAP SPLICING HIGH TENSILE STEEL BARS IN REACTIVE POWDER CONCRETE BEAMS EXPOSED TO REPEATED LOADING

الملخص

This research is an experimental study to evaluate the effect of lap splice of high-strength steel bars in reactive powder concrete beams exposed to repeated loading. Seven Reactive Powder Concrete (RPC) beams whose tension steel bars were spliced at mid-span and one RPC beam without lap splice were casted and tested. These beams were simply supported and tested up to failure under the action of two point loads (two beams exposed to monotonic load and five beams exposed to repeated load). The studied parameters were : the repeated loading regime (two different repeated loading regime depending on the minimum to maximum applied load),the lap splice length ( 20 and 30 times diameter of bar diameter), the concrete cover thickness (30mm and 40mm) and adding steel stirrups within the lap splice region. The mid span deflection as well as cracks propagation were recorded for each load step in tested beam. The main results showed that the adopted spliced length of tension steel bars was sufficient in monotonic load but insufficient under the action of greater number of cycles of the repeated load.