Non-ductile reinforced concrete frames with unconfined joints dominate the collapse hazard of the existing building stock. Their CFRP-retrofit margin at collapse demand is poorly quantified. Two one-third-scale portal sub-frames were tested under Froude similitude. Specimen 1 was bare. Specimen 2 carried a three-ply hoop CFRP jacket on columns, beams, and joints. Both received the Antakya 3141 record from the 2023 Kahramanmaraş $M_w$ 7.7 mainshock at design intensity 0.35 g and collapse intensity 1.0 g. Cyclic response was decomposed into flexural, shear, and slip energy. At design intensity, the retrofit cut peak roof drift by 54%, suppressed residual offset, and lowered the calibrated Park–Ang index from 0.89 to 0.32. Slip share dropped from 47% to 5%. At collapse intensity, the retrofitted frame transitioned to joint-panel debonding-controlled failure at 8% drift with 245 mm residual, and shear share rose to 64%. The dominant-half-cycle ratio $R_1$ ≈ 0.72 emerged as a candidate brittle-damage signature for collapse-level response. A Lam–Teng confinement check confirms that the failure migrates from the column ends to debonding fracture in the wrapped panel rather than being eliminated by the retrofit. Supplementary joint-corner anchorage is recommended for non-ductile joints at collapse demand.

Uncontrolled solid waste affects the stress-strain behavior of the sand as well as causes an environmental problem. In this research, the effect of leachate on the dynamic behavior of sand has been studied and the results were compared with clean sand with different saturation degrees. The modified split molds at 50 mm diameter and 100 mm height were used to prepare the leachate-contaminated sand. Both contaminated and clean sand samples were prepared by dry pluviation method. After preparation, the sand samples in the modified mold were put in the leachate wastewater to keep for different cure times. Then they were installed on the dynamic triaxial test system at 0.1 Hz and the same cyclic stress ratio. During the saturation process to prevent the structure of contaminated sands from being disturbed, samples were not passed through CO2 and distilled water. Stress-controlled cyclic tests were conducted at on both clean and contaminated sand consolidated at 100 kPa isotropically. After consolidation phase the measured B values varied between 0.45-0.93. Results show that leachate-contaminated sands are more liquefiable depending on cure time at the same saturation value and saturated clean sand samples and partially saturated leachatecontaminated sand samples show similar liquefaction behavior under the same cyclic ratio.

Pamukkale University Journal of Engineering Sciences