EVALUASI KELAYAKAN DIMENSI DAN BIAYA ELEMEN STRUKTUR ATAS BETON BERDASARKAN MUTU MATERIAL EKSISTING (Studi Kasus: Konstruksi Villa Serenity Ubud, Gianyar)

Abstract

This study aims to evaluate the feasibility of cross-sectional dimensions and structural costs of reinforced concrete elements in the Villa Serenity construction project based on the existing quality of materials. The evaluated elements include tie beams, columns, and beams, which act as the main load‑bearing components resisting gravity and seismic actions. The in‑situ concrete strength was assessed using the rebound hammer test, while the quality of reinforcing steel was determined through laboratory tensile tests, and then checked against the requirements of SNI 2847‑2019 and SNI 2052‑2017. Structural modeling and internal force analysis were carried out in SAP2000 using load combinations in accordance with SNI 1727‑2020 and SNI 1726‑2019.​ Structural adequacy was evaluated by comparing the nominal flexural, shear, and axial capacities of each section with the corresponding design internal forces. The results indicate that several tie beams, columns, and beams, particularly on the upper floors, do not satisfy the required design capacity because the actual concrete and steel strengths are lower than the design specifications. These inadequate elements are recommended to be modified through enlargement of cross‑sectional dimensions and adjustment of reinforcement details so that the required strength criteria are fulfilled.​ A structural Cost Budget Plan (RAB) was then prepared based on the revised work volumes and the 2025 Analysis of Unit Prices (AHSP) for Gianyar Regency, resulting in a total estimated structural cost of approximately IDR 3,173,794,000.00. The findings highlight the importance of verifying existing material properties and re‑evaluating section dimensions before continuing construction, and demonstrate that field‑based evaluation supports the application of value engineering to achieve safer and more economical structural designs