Modern seismic design and technologies have undergone tremendous developments. In modern design codes, building structures subjected to high earthquake loads are allowed to experience plastic deformations without collapsing, and the design is permitted up to the ultimate strength. According to comparative results in Japan, the number of humans injured due to earthquakes is higher than the number of deaths/missing. Likewise, the number of residential buildings that collapsed are less than the partially damaged buildings. This outcome implies that residential buildings designed based on the revised seismic standards have good earthquake resistances. It also infers that the human deaths/injury casualties were not a result of the collapsed the structure, but due to the strong vibrations originated from the earthquake, yielding in the collapse of non-structural elements such as ceilings and bookshelves. This paper presents a proposed design philosophy that attempts to implement the effect of earthquakes to non-fatal human casualties

In this study, a nonlinear 2D rigid body spring model (RBSM) was developed to verify the experimental works of Carbon Fiber Reinforced Polymer (CFRP) sheets and rods strengthened reinforced concrete (RC) T-shape beam (RC T-beam) section under a combination of bending and shearing loads. Modified Mohr–Coulomb criteria were adopted for modeling the plastic damage of concrete material. The orthotropic smeared layers representing the steel and CFRP materials were laminated on the concrete surface to model the reinforcing steel bars, stirrup steel, and CFRP sheets and rods. A mechanical behavior-based approach to fit the experimental results was discussed using the numerical results at each calibration stage. This study shows how the gradient of compressive and ultimate tensile strength of concrete affects the initial flexure behavior of the load-displacement curve of an RC T-beam. In contrast with finite element modeling, the RBSM can exhibit the crack propagation processes of element separation during the simulation. The calibrations showed the agreement of the models used in predicting the flexural behavior, ultimate load, and strengthening effects of the CFRP sheets and rods to the RC T-beam under bending loads. A systematic calibration procedure combined with the recommended use of energy-based criteria to evaluate the results of calibrated load-displacement curve was proposed.

Era kini ditandai dengan penekanan pada konsevasi energi, beton ramah lingkungan dan beton hijau. Semen merupakan bahan utama pembentuk beton, dan juga penyumbang pencemaran udara terbesar di antara bahan penyusun material tersebut. Semen slag atau Ground Granulated Blast Furnace Slag (GGBFS) yang merupakan hasil pengolahan limbah industri baja menjadi salah satu alternatif yang diminati karena proses produksi dan lebih ekonomis bila dibandingkan dengan Portland Cement (PC). Material yang mempunyai sifat cementitious ini berpotensi untuk menggantikan sebagian semen dalam campuran beton dengan tetap mempertahankan kelebihan sifat mekanis beton. Penelitian ini dilakukan di laboratorium dengan pengujian benda uji yang telah didesain dengan komposisi substitusi semen slag sebesar 0%, 10%, 20%, 30%, 40%, dan 50% dari berat semen yang dibutuhkan dan pada umur 28 hari. Sebagai benda uji kontrol beton direncanakan dengan kuat tekan f’c = 38 MPa. Semen slag yang digunakan berdasarkan referensi memiliki activity index grade 80. Penelitian dilakukan untuk mengetahui kinerja semen slag pada beton melalui pengamatan kuat tekan (f’c), hubungan tegangan-regangan (fc - ε) dan modulus elastisitas (E) beton. Pengujian menunjukkan bahwa substitusi slag menyebabkan terjadinya penurunan kuat tekan beton, regangan dan modulus elastisitas pada umur 28 hari karena adanya proses kimia yang lebih lamban daripada PC.