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Approach to risk management, knowing the potential risks in realizing the construction of dam construction on the side of the work owner in the East Java area. In constructing a dam, construction on the job owner can affect the project's success. A practical risk management approach is carried out to achieve schedule, cost, quality, and service. This research aims to identify risks and provide a priority order of risks for the owner of the dam construction project in East Java that are most likely to occur to minimize the consequences arising from these risks. The identified risks will then be researched using the Failure Mode and Effect Analysis (FMEA) method. Then, the highest risk priority sequence will be obtained to determine the appropriate risk response in addressing these potential risks. In the next dam construction, the work owner will know the most significant potential risks to minimize cost overruns, time, and quality.

The present research focuses on studying the structural performance of reinforced concrete frame structures with one-way eccentric bracing due to lateral load, including stress–strain relationships and bending capacity. The effectiveness of various eccentricities was also inspected. In this experimental study, three reinforced concrete frames with simple beam-columns were investigated. Due to the limited number of tested specimens, this research cannot have a general validity and the main point is to clarify the advantages and disadvantages of eccentric one-way braces with respect to concentric ones. The dimensions, including the 70 cm height and 100 cm length were investigated. The first model, without eccentricity (called CBF), was used as the basic model. Meanwhile, other models were given eccentricities of 15 cm and 30 cm on the upper side (called EBF-15 and EBF-30). The main reinforcement was O6 mm with O4–150 stirrups. The load was measured using a load cell applied laterally. The results state that EBF-15 has a similar result to the maximum load and displacement of the CBF. However, the stress–strain relationship shows that EBF-15 has a larger strain. In addition, the largest moment capacity, 30.27 kN m, is shown in CBF, while EBF-15 and EBF-30 are 30.20 kN m and 14.41 kN m, respectively. Therefore, the smaller eccentricity of EBF has a close advantage to CBF and can be an alternative to change concentric bracing to eccentric due to difficulty in applying to a real structure.

To find out the quality of concrete, we need to test the concrete. Which is non destructive test or testing without damaging the test object, namely with an UPV (Ultrasonic Pulse Velocity). In this study using 4 variations of coarse aggregate composition (mix design), namely porous variation, RCA (Recycled Coarse Aggregate) variation, pumice variation and fiber variation. The UPV test results in this study show that the relationship of compressive strength with amplitude (A1) or transmission time (t0) is concluded that the low homogeneity value causes higher energy loss so the amplitude value becomes lower and the value transmission time depends on the density of the concrete. In the value of compressive strength that affects homogeneity, it does not mean the higher the uniform material (homogeneity), the higher the compressive strength value. Keywords : Amplitude, Concrete, Compressive Strength, Ultrasonic Pulse Velocity, Transmission Time

Some previous research indicated that a short link beam in an Eccentric Braced Frame (EBF) yields due to shear rather than flexure. Stirrups inside a concrete beam structure are functioned to carry shear forces beside concrete material itself. It means that the effect of spacing between shear stirrups is a very important aspect in increasing a short link beam structural capacity. Present study used EBF with brace V-type (EBF-V) due to its good performance compared to diagonal and inverted-V. Seven reinforced concrete braced frame structures consist of one EBF-V with short link stirrup space of 150 mm, three EBF-V with short link stirrup space of 75 mm and three Concentric Braced Frame V-type (CBF-V) as control models. Under cyclic loading conditions, load-displacement relationship and crack positions were observed. Results indicated that CBF-V models have the highest maximum load. On the other hand, EBF-V has a larger displacement than CBF-V. Smaller stirrup space results in a slightly higher strength but lower ductility. Crack visualizations of CBF-V and EBF-V model are also presented.

The study presents the potential use of Kelud volcano eruptive deposits, Indonesia which includes river sand as fine aggregate, pumice as well as scoria as coarse aggregate of green structural lightweight concretes. Their physical properties were experimentally tested and compared with controls that were commonly used in the region. Furthermore, they were applied on pumice and scoria lightweight concretes designed for five determined compressive strengths and compared with normalweight concrete as a control. The physical properties of fresh and hardened concretes as well as the mechanical properties were also investigated experimentally. Precast slab units of both lightweight concrete were used as their structural application and evaluated for their maximum bending capacity, stiffness and self-weight then they were also compared to the control. The results stated that the river sand, pumice as well as scoria fulfilled the fine and coarse aggregate requirements for lightweight concrete. The pumice and scoria lightweight concretes obtained were the structural lightweight concretes with the compressive strengths were approximately 30 MPa and the density reductions were about 22%. For the similar determined compressive strength, the maximum bending capacities of both lightweight concrete precast slab units were quite high and the self-weights at 28 days were about 85% lower than the control. However, the stiffnesses were lower than the control so that their deflections must be considered in the design.

An abutment is a sub-structure that shall be designed as no damage to withstand all external loads. However, many abutments collapsed subjected to severe earthquakes. Besides, the pounding between superstructure and sub-structure has an impact on the performance of abutment. This research is focused on crack propagation of the abutment back wall-unified wing wall subjected to horizontal incremental load with numerical and experimental analysis. According to the analysis, the crack propagation phenomenon is similar which is developed near the connection between the abutment back wall and its support. Hence, further study is needed to evaluate the behavior of full type abutment subjected to liquefaction load.

Rawannya korban gempa bumi akibat keruntuhan dinding, konsep pembangunan ramah lingkungan, serta efisiensi kinerja merupakan tiga aspek yang menuntut adanya inovasi di bidang konstruksi. Sejalan dengan perkembangan teknologi, salah satu inovasi tersebut adalah panel jaring kawat baja tiga dimensi yang merupakan produk SIPs, sebagai alternatif material penyusun dinding. Penelitian kemudian dirancang menggunakan dua seri spesimen, yaitu M4 dengan tebal EPS 40 mm dan M8 dengan tebal 80 mm. Keduanya memiliki lebar dan tinggi dinding berturut-turut 600 mm dan 900 mm, dengan tebal mortar mutu K175 yang disemprotkan 35 mm pada kedua sisi dinding, yang kemudian diangkurkan pada balok sloof. Pemberian beban dilakukan secara siklik dengan protokol pengujian berdasarkan kontrol defleksi. Mengacu pada analisis eksperimental, diperoleh bahwa energi disipasi pada seri M4 hampir 20% lebih besar dibandingkan seri M8. Sedangkan rasio redaman ekuivalen pada kedua seri spesimen dinding panel relatif sama.

This study presents the evaluation of the use of bamboo fiber to improve the performance of bamboo reinforced concrete at the tension crack area. To achieve this objective, a series of tests were conducted. The size object of concrete beam is 15 cm × 20 cm × 160 cm with reinforcement of bamboo and pumice stone aggregate. Bamboo reinforcement was coated with sand to become rough of the surface. The type of bamboo obtained from skewer producers in the Cemoro Kandang Malang is called Ori bamboo. The fiber were used vary in length. The fiber coated with paint and covered with sand to prevent the hygroscopic properties and increased the weight to prevent the float of bamboo fibers when mixed in the concrete mixer. The results were showed that bamboo fiber can reduce crack-width and deflection of concrete and increase beam post-cracking load-carrying capacity. The amount of fiber has effect on workability and quality of concrete. However, bamboo fiber can prevent the growth and propagation of cracks.

Seismic isolation is the most important in earthquake resistant structural design. Many isolation techniques have been developed to reduce the impact of earthquake. The seismic responses of eleven-storey models of folded cantilever shear structure as a proposed structure have been studied numerically. Folded cantilever shear structure (FCSS) consist of fixed-movable-fixed supported shear sub-frames and connection rigid sub-frame which connect their sub-frames at the top. The movable sub-frame is supported by roller bearings and additional viscous damper are attached laterally between beams. In order to evaluate the efficiency of the seismic isolation system and the effect of earthquake ground motions, different structures as fixed base, rubber bearing system, and folded cantilever shear structure were analyzed. The analyses were carried out under some ground motions namely El-Centro 1940, Hachinohe 1968, and Taft 1952 earthquakes. The maximum acceleration and displacement responses for the seismic isolation were reduced generally. The main objective here is to make a comparison between the seismic isolation and fixed based structure, rather than comparing the seismic isolation within themselves. The earthquake responses are compared and results are discussed.

Seismic performances of sixteen-storey folded cantilever shear structure (FCSS) with roller bearing and additional viscous damper have been studied using a shake table. The structures consist of fixed-movable-fixed supported shear sub-frames and connection rigid sub-frame which connect their sub-frames at the top. The movable sub-frame is supported by roller bearings and additional viscous damper are attached laterally between beams. Experimental and numerical analyses were conducted to identify dynamic responses of model with and without additional viscous damper. In order to observe the efficiency of the additional viscous damper and the effect of earthquake ground motion under three different strong ground motions, namely El-Centro, Hachinohe, and Taft earthquakes, both numerical analysis and shaking table test of the model with and without additional viscous damper were conducted. The maximum displacements, for top fixed floor and bottom movable floor were significantly reduced with the addition of viscous damper system of structure. A reasonable agreement between results obtained from numerical analysis and shaking table test were also obtained.