This study focuses on the monitoring of rusted and non-rusted rebar protected by sacrificial anode cathodic protection until 1000 days. Three specimens of RC beam structures having a length of 580 mm and 150x100 mm cross-section are fabricated. Two reinforcing barwith the same surface condition (ø 13 mm) were embedded in mortar parallel to each other with the intermediary distance of 40 mm and the cover depth of 30 mm in the bottom surface of the specimen. Discrete sacrificial zinc anode is connected to one rebar in patch repair section. During the investigation, the specimenswere exposed under three conditions, i.e., 20°C air curing, dry-wet cycle, and dry laboratory air. Potential of both rebar and sacrificial anode was monitored to check the condition of the cathodic protection system. The result indicates that non-rusted rebar condition in repaired patch concrete (chloride-free) is the most desirable initial condition when the sacrificial anode is applied on it to protect corroded steel bar in existing concrete (chloride contamination).

Penelitian ini berfokus pada analisis perilaku dinamis dan stabilitas struktur rumah adat bugis yang tahan terhadap beban gempa. Menggunakan kayu Bitti (Vitex cofassus) dan kayu Ipi (Intsia bijuga O.K) sebagai bahan utama rumah adat Bugis dalam penelitian ini. Sebuah model dengan skala penuh dari rumah struktur untuk menganalisis perilaku dinamis dan stabilitas struktur, termasuk sambungan balok-kolom menggunakan SAP2000 dengan berbagai beban berdasarkan SNI 1727:2013, Spesifikasi Desain Indonesia untuk Beban Desain Minimum untuk Bangunan dan Struktur Lainnya. Mempertimbangkan perkembangan zaman, penelitian ini menggunakan jenis atap yang bervariasi, yaitu atap daun rumbia, atap seng, dan atap genteng. Response Spectrum digunakan untuk beban gempa pada struktur ini. Hasil gaya ultimit dari analisis SAP2000 akan dibandingkan dengan gaya nominal masing-masing komponen struktur, untuk menganalisis rasio tegangan akibat gaya internal. Hasil analisis menunjukkan bahwa kekuatan struktur kolom kurang kuat. Namun, anggota lain masih aman untuk digunakan, meskipun menggunakan atap yang berbeda. Dapat disimpulkan bahwa anggota Rumah Adat Bugis tidak sepenuhnya aman.

The accumulation of corrosion product on the steel surface may cause eventual failure to deliver of ionic current protection from sacrificial anode cathodic protection. The effect of cleaning of deteriorated steel bar before cathodic protection application is studied in this paper. Two specimens having a length of 580 mm and 150x100 mm of the cross-sectional area with deteriorated reinforcing bar and half-part of chloride contaminated concrete were fabricated to simulate the repair process. Two corroded reinforcing bar with the same surface condition (ø 13mm) were embedded in concrete parallel to each other with the intermediary distance of 40 mm and the cover depth of 30 mm in the bottom surface of the specimen. In the first specimen, rust on the steel bar surface in the repair section was removed. Discrete sacrificial zinc anode is connected to one steel bar in the repair section. During three-years observation, the specimens were exposed to several conditions: 20°C air curing, dry-wet cycle, dry laboratory air, and wet condition, respectively. Potential of both rebar and the sacrificial anode was monitored to understand the performance of the cathodic protection system. The result indicates that rust removal process of steel bar surface in repair concrete part is the most desirable initial condition when the sacrificial anode is applied on it to protect corroded steel bar in new and existing concrete.

Geopolymer is a renewable construction material that reduces dependence on ordinary portland cement (OPC), where OPC manufacturing impacts carbon dioxide (CO 2 ) emissions. The main aspect of geopolymers being studied is the precursor of pozzolanic material, used as a cement substitute because it contains aluminosilicate (Si-Al). Polymerization occurs between the precursors, reacted by alkaline activator solution (AAS). Sodium hydroxide (NaOH) and sodium silicate (Na 2 SiO 3 ) were used as AAS. In this study, local precursors from industrial waste and biomass were utilized. Fly ash was employed as a reference in the precursor by 5% -10% substitution of glass powder, rice husk ash, bagasse ash, and palm shell ash. Moreover, 2% superplasticizer and 5% extra water were used to increase the flowability of fresh geopolymer. Tests were carried out on the setting time of paste, flow table, and compressive strength of geopolymer mortar. The tests were on the initial setting time of 25-75 minutes and the final setting time of 40-115 minutes. The setting time results revealed that the time of each substitution accelerated geopolymerization due to the substitution of precursors containing higher CaO and SiO2. Setting time and flowability/workability had a linear regression correlation (R 2 ) of 0.95, with the flow table ranging from 180-250 mm. The compressive strength ranged from 25.88 -36.36 MPa through a curing temperature of 70 o C for 24 hours, followed by curing at ambient temperature for up to 28 days.