In precast concrete, a connection is needed to unite the components so that they become a whole unified structure. This study aims to determine the reinforcement strength and length of reinforcement in precast concrete connections. To paste reinforcement into precast concrete, giving additional material in the form of grouting which is called sika grout 215 and functions as an adhesive is necessary. Pullout testing is carried out in the laboratory, and its simulation by modeling uses the finite element method based software. This research is divided into 2 phases. The first phase is making specimen to examine the bond strength between the concrete and reinforcement that has been given sika grout 215. So monolithic specimen is made as a comparison. The result of the bond strength of the monolithic test specimen is 6.24 MPa, and the sika grout 215 category is 6.52 MPa. From the experimental results in the laboratory with modeling, it is obtained the bond strength ratio of 0.94. The length of development (ld) based on the results of the testing phase I of 200 mm. The second phase is examining the damage pattern due to the stress that occurred. Specimens are made into 4 categories, namely modeling developments with the length of 120 mm (<40% ld), with the length of 160 mm (<20% ld), with length of 200 mm (= ld), and with the length of 260 mm(> 30% ld) both for monoliths and sika grout 215. The damage pattern, which is in the form of yielding and breaking reinforcement as the result of the pullout experiment in the laboratory shows not much different from the result of simulation using the software.

High strength bolt joints used on the steel truss bridge are the mechanism of slip-critical. This mechanism relies on the clamping force of high strength bolt pretension led to friction between the surface of the tied steel plates, so the forces acting on the elements of the steel bridge held by the friction. In order to get the ratio of the pretensioning and observe the mode of failure, then the experiments in the laboratory and the simulation using software were carried out. The method used in this experiment was trial and error so that the value of the pretensioning of high strength bolts needed to reach the maximum axial load press was retrieved. There are four types of the surface coating of the tied steel; milling, grit-blast cleaning, coat of primer paint by grit-blast cleaning and coat of hot-dip galvanized given chromate treatment. The results obtained show that the ratio of the pretensioning on high strength bolt between the simulation and the experiments do not look different; the range is 0.97. The pattern of failure that occurs in the simulation tends to be more regular and quite small in comparison with the experimental results.

Numerical analysis is one way of approach method to study the behavior of the structure is quite effective in terms of time, cost and equipment used. ATENA one of the software-based on finite element method. Hollow cross section is one way to reduce theself weight of concrete beam. The effect of holes on beam is reduce the bending resistance. Hollow beam is modeled in a numerical model which is then analyzed by using the ATENA program v.2.10. Material parameters used as input data is the result of laboratory tests, assuming bond steel and concrete are considered prefect bond and steel reinforcement is modeled discrete. The results of numerical analysis of the ATENA were then compared with experimental test results on the flexural behavior and serviceability limit state of reinforced concrete hollow beams lengthwise (Amir, 2010), then study the variation of quality parameters of concrete and the hole size variations. The results showed that the collapse load hollow beam only reaches 96.71% and deflection reached 135.96%. Stiffness of hollow concrete beam was also showed a higher stiffness of the experiment. The crack pattern that occurs is flexural fracture and crack-like fracture experiments. Test parameters of concrete quality variations as well as the hole size variation showed higher concrete quality/ size of the hole will reduce the ductility of beam. Keywords: reinforced concrete, elongated hollow beam, flexural, ductility, crack ABSTRAK Analisis numerik adalah salah satu cara pendekatan untuk mengetahui perilaku struktur yang cukup efektif dalam segi waktu, biaya dan peralatan yang digunakan. Program ATENA adalah salah satu perangkat lunak yang berbasis metode elemen hingga. Balok beton dengan penampang berlubang merupakan salah satu cara untuk mengurangi beratnya. Pengaruh lubang pada penampang balok tersebut tentunya akan berpengaruh terhadap kemampuannya menahan lentur. Balok berlubang dimodelkan dalam model numerik yang kemudian di analisis dengan menggunakan program ATENA v.2.10. Parameter material yang dipakai sebagai input data merupakan hasil uji laboratorium, asumsi lekatan baja tulangan dan beton dianggap prefect bond serta baja tulangan dimodelkan diskrit. Hasil analisis numerik dari ATENA tersebut kemudian dibandingkan dengan hasil pengujian eksperimen perilaku lentur pada keadaan layan dan batas balok beton bertulang berlubang memanjang (Amir, 2010), kemudian dilakukan studi parameter terhadap variasi mutu beton dan variasi ukuran lubang. Hasil penelitian menunjukkan bahwa beban runtuh balok berlubang hanya mencapai 96,71 % dan lendutan mencapai 135, 96 %. Kekakuan balok beton berlubang ternyata juga menunjukan kekakuan yang lebih tinggi dari eksperimen. Pola retak yang terjadi merupakan retak lentur dan menyerupai retak eksperimen. Uji parameter terhadap variasi mutu beton maupun variasi ukuran lubang menunjukkan semakin tinggi mutu beton/ ukuran lubang maka nilai daktilitasnya menurun. Kata kunci : beton bertulang, balok berlubang memanjang, lentur, daktilitas, retak

Numerical analysis is a time-, cost- and equipment-effective method to study the behavior of structures. ATENA is one of the available software-based on finite element method. Hollow cross section is one way to reduce the weight of concrete beam. The effect of holes on beam may reduce the bending resistance. The hollow beam was numerically modeled which and subsequently analyzed using the ATENA v.2.10 software. Material parameters being used as input data was obtained from laboratory tests, assuming that steel-concrete bond was prefect, and and the steel reinforcement was modeled as discrete. The results of numerical analysis of the ATENA were then compared with experimental test results on the flexural behavior and serviceability limit state of reinforced concrete hollow beams lengthwise (Amir, 2010), then study the variation of quality parameters of concrete and the hole size variations. The results shows that the collapse load of hollow beam reached only 96.71% and deflection reached 135.96%. Stiffness of hollow concrete beam was also showed a higher stiffness of the experiment. The crack pattern is flexural fracture and very much agree with that of the experiments. Test parameters of concrete quality variations as well as the hole size variation showed higher concrete quality/size of the hole will reduce the ductility of beam.