Experimental evaluation of CDW mortar as a sustainable alternative to epoxy for post-installed reinforcement bar anchorage

This study experimentally evaluates construction and demolition waste (CDW) mortar as an alternative bonding material to epoxy adhesive for post-installed reinforcement bar anchorage in low- and moderate-strength concrete substrates. The mortar incorporates recycled CDW fine aggregate to provide a low-cost and resource-efficient material for strengthening applications. A total of 72 pull-out tests were conducted considering three concrete strength levels (C10, C15, and C20), two reinforcement bar diameters (Ø12 and Ø14), and two embedment depths (7d and 10d). The results were assessed in terms of system-level pull-out capacity, failure mode, load–displacement response, statistical variability, and material-only unit cost. The CDW mortar showed comparable anchorage response to epoxy in most configurations, particularly for larger bar diameters, although the response was strongly influenced by substrate-controlled failure. Splitting failure was dominant, occurring in 47 tests, while pull-out failure occurred in 25 tests. Thus, the reported capacities represent system-level anchorage performance rather than intrinsic adhesive bond strength. The indicative material-cost assessment showed that the CDW mortar offers potential economic advantages based on current Türkiye market data. Overall, CDW mortar appears promising for selected anchorage applications in weak concrete substrates.