INTERNATIONAL JOURNAL FOR INNOVATIVE RESEARCH IN MULTIDISCIPLINARY FIELD

The bond behaviour between reinforcement and surrounding concrete is essential to the strength, ductility, and serviceability of precast concrete structures, where joint performance is critical. Mechanical anchorage systems like grouted sleeves and threaded couplers, though widely used, face limitations: grouted sleeves are highly sensitive to grout quality, placement, and bar alignment, while threaded couplers require precise cutting and threading, making them labour-intensive and prone to stress concentrations under cyclic loading. To address these issues, this study investigates an innovative anchorage system using aluminium sleeves filled with non-shrink polymer-modified grout (UltraTech NS-1) to house helically ended reinforcement bars through which a straight bar is passed along the axis, providing a secure mechanical connection. Two specimen categories—C2–10 mm (Fe-415, 130 mm embedment) and C2–12 mm (Fe-500, 190 mm embedment)—were cast in M40 concrete and subjected to displacement-controlled pull-out tests to record load–slip responses, bond strength, and failure modes. The same specimens were simulated using Abaqus/CAE to replicate experimental conditions, capture nonlinear bond–slip behaviour, and evaluate stress transfer at the steel–concrete interface. The model employed identical geometry, material properties, and testing conditions for direct comparison and validation. A parametric study was then conducted by systematically decreasing development length while keeping other parameters constant to isolate its effect on bond performance. Results showed close agreement between experimental and numerical load–displacement behaviour across dowel lengths, with 10 mm specimens failing by slip and 12 mm specimens failing by rebar fracture, confirming effective dowel action. Bond strengths generally exceeded the grout capacity of 8 N/mm² except in shorter embedments (8d and 6d) of 12 mm bars. These findings establish the proposed anchorage as a reliable solution with robust bond performance, effective stress transfer, and suitability for precast and retrofitting applications.