Experimental Study of Interior Glass Fiber-Reinforced Polymer-Reinforced Concrete Slab-Column Connections under Lateral Cyclic Load

摘要

The authors should be complimented on their pursuit of the issue of seismic behavior of GFRP-RC slab-column connections. This discussion is motivated primarily by concerns regarding the approach followed to select and design the test specimens and in interpreting the test results. The objective of this discussion is to obtain additional clarifications that should be useful for future readers. It was mentioned in the discussed paper that the slab dimensions were selected to represent the locations of contraflexure lines. Although these locations were not specified in the paper, it can be interpreted from the used slab dimensions and span length of the prototype structure. The simply supported slab dimensions of the tested specimens were 2000 × 2000 mm, while the span length of the prototype structure was 5000 mm. This implies contraflexure lines at 20% of the span length. Although this assumption is reasonable in the case of connections subjected to gravity loads only (Dulude et al. 2013; Gouda and El-Salakawy 2015), it does not necessarly represent accurate boundary conditions of connections subjected to cyclic lateral loads. Due to the reversed nature of cyclic lateral loads, contraflexure lines are typically assumed at midspan of slabs and beams in slab-column and beam-column connections, respectively (Pan and Moehle 1989; Robertson and Johnson 2006; Mady et al. 2011; Draktos et al. 2016; Ghomi and El-Salakawy 2015). Having the specimens simply supported close to the column, at 20% rather than 50% of the span, is expected to significantly affect the behavior of the specimens. For instance, if a larger slab was used, the effects of the gravity load would have been significantly intensified due to the larger supported span of the slab. The specimens would have exhibited significant deflections under the application of gravity loads in addition to a considerable amount of damage and stiffness degredation prior to the application of lateral loads. Consequently, they might not have been capable of sustaining the drift ratios reported in the paper.