Analysis of Four Types of Anchorage Devices for Prestressed Glulam Beam and Experimental Research

An anchorage device is an integral part of the prestressed Glulam beams. Therefore, its rationality and practicability have significant effects on the mechanical performance of the prestressed beams. To investigate the impact of the anchorage devices on the bearing capacity and stiffness of the prestressed beams, this paper compared and analyzed four kinds of anchors in detail through the finite element software. The results showed that when the initial mid-span deflection was 5 mm, 10 mm, and 15 mm, the bearing capacity of prestressed beams with four anchorage devices was 80.37–177.24%, 93.56–182.51%, and 95.62–194.60% higher than that of ordinary Glulam beam, respectively. When the initial mid-span top prestresses were 1 MPa, 1.5 MPa, and 2 MPa, the bearing capacity of prestressed beams with four anchorage devices was 101.71–172.57%, 105.85–175.88%, and 109.64–180.87% higher than that of ordinary Glulam beam, respectively. In addition, based on the simulation results, the prestressed beam with the external anchorage had the highest bearing capacity and stiffness. The deformation capacity of the beam with boot anchorage was the largest. The stress distribution of the beam installed under beam anchorage was the most uniform, and the beam with slotted anchorage was easy to cause stress concentration at the notch. Finally, based on the outstanding performance of the external anchorage, it was selected to carry out one experiment, and the experimental result showed that the simulation could predict the damage model and load–deflection relationship of the prestressed beams well.

Analysis of Multi-Storied Building with Prestressed Beam using ETABS

Concrete is good in compression and weak in tension and the steel is strong in tension. So the use of reinforced concrete to resist compression and to hold bars in position and to the steel resist tension. In India RCC structures are commonly used in residential as well as business buildings. Nowadays the Post Tensioning method is widely used due to its advantages. Post tensioning is a form of prestressing, that means the steel is stressed before the concrete has to support the service loads. In this paper is exposed to the assessment of execution of Reinforced concrete beam (RCC beam) and Post-Tensioning beam (PT beam) multistoried building structure framework with seismic load using ETABS software. And also evaluate the performance of PT beam under different seismic zone (zone I, zone II) evaluate the performance of PT beam under soil type (medium soil) and compare the performance of RCC deep beam and PT beam with multistory building system with seismic loading performance.

The Behavior of Reinforced and Pre-Stressed Concrete Beams under Elevated Temperature

The behavior of unbounded post tension and reinforced concrete beams under elevated temperature was presented. The experimental work was consisted of two major phases. In the first phase, the objective was studying the mechanical performance of prestressed beam, prestressed beam with steel addition and reinforced concrete beams respectively were studied. In the second phase, the residual mechanical performance of prestressed beam, prestressed beam with steel addition and reinforced concrete beams under elevated 400oC, for 120 minutes durations. The failure mechanisms, ultimate load capacity, and deflection at critical sections were monitored. The numerical prediction of the flexural behavior of the tested specimens is presented in this paper. This includes a comparison between the numerical and experimental test results according to ANSYS models. The results indicate that the prestressed beam with steel addition and reinforced concrete beams had higher resistance to beams under elevated 400oC than that of prestressed concrete beam in terms of ultimate capacity. It is also shown that the reinforced concrete beams have higher resistance to beams under elevated temperature than that of prestressed beam, prestressed beam with steel addition.

Studi Mengenai Analisis Penampang Balok Prategang Parsial pada Beban Kerja. (Hal. 83-95)

ABSTRAKPenampang balok prategang parsial dapat dirancang dengan dua metode analisis yaitu metode analisis terhadap beban runtuh dan metode analisis terhadap beban kerja. Perancangan penampang balok prategang parsial pada umumnya dilakukan dengan menggunakan metode analisis terhadap beban runtuh yang telah ditetapkan dalam SNI 03-2847-2002, namun perancangan menggunakan pendekatan beban kerja tidak dicantumkan. Oleh karena itu dilakukan studi analisis untuk mengetahui sejauh mana metode analisis terhadap beban kerja dapat diaplikasikan dalam perancangan penampang balok prategang parsial. Studi kasus ini dilakukan dengan persentase 60, 70, 80, dan 90. Dari hasil studi kasus didapatkan bahwa dengan menggunakan metode analisis terhadap beban kerja dapat dilakukan namun dengan batasan persentase prategang yang beragam yaitu 90, 95, dan 99. Metode analisis terhadap beban kerja dapat dilakukan pada kasus-kasus tertentu dan menggunakan beton dan tendon dengan mutu tinggi untuk faktor keamanan bangunan.Kata kunci: beton prategang parsial, pendekatan beban kerja, persentase prategang, lebar retak ABSTRACTPartial prestressed beam section can be designed with two analysis methods are failure load analysis method and service load analysis method. The design of the partial prestressed beam section generally is using the failure load analysis method which has been specified in SNI 03-2847-2002, but the design with the analytical method of service load is not included. Therefore an analytical study was conducted to determine the extent to which the service load analysis method can be applied for the design of a partial prestressed beam section. This case study was carried out at 60, 70, 80, and 90 prestressed percentages. From the case study results it was found that using the analysis method of service load can be done but with variations of a limited percentage are 90, 95, and 99. The method of analysis of workload can be done in certain cases and using high-quality concrete and tendons for building safety factor.Keywords: partial prestressed concrete, service load analysis method, prestressed percentage, crack width

Perencanaan Jembatan Beton Prategang Dengan Bentang 24 Meter Berdasarkan Standar Nasional Indonesia (SNI)

Bridge is used to connect divided road sections, which are seperated by obstacles such as deep valley, river, lake, irigation canals, railway, and also grade seperated roadway. The construction of a bridge must comply with several requirements namely stiffness, deflection, and load bearing requirement. This research is a structural analysis and design of prestressed concrete girder beam with 24m length and 6.5m width. Working loads are dead load (MS), additional dead load (MA), vehicle load (TD), braking load (TB), pedestrian load (TP), and wind load (EW). Internal forces are obtained using Finite Element Method in SAP2000 nonlinear. Design of the bridge structure follows the national standar SNI 1725:2016 and RSNI T-12-2004. Result of structural design and analysis of the prestressed concrete girder beam uses 4 prestressed beam (160cm height, 1.83m distance between beam), 20cm bridge slab, and diaphragm with the dimension of 20x165x125cm . The number of tendon used in the design is 3, and each tendon comprises of 12 strand. The amount of prestressed force caused by jacking is Pj=5351.30 kN with loss prestress 24.52%. Deflection caused on the prestressed beam is dmaks = 12.6 mm (<dijin =80 mm), and occuring stress is 8696 kPa (< allowed stress 18675 kPa).

Deflection of Steel Reinforced Concrete Beam Prestressed With CFRP Bar

Carbon Fiber Reinforced polymer (CFRP) bars are weak in yielding property which results in sudden failure of structure at failure load. Inclusion of non-pretensioned steel reinforcement in the tension side of CFRP based prestressed concrete beam will balance the yielding requirements of member and it will show the definite crack failure pattern before failure. Experimental investigation has been carried out to study the deflection behavior of partially prestressed beam. Experimental works includes four beam specimens stressed by varying degree of prestressing. The Partial Prestressing Ratio (PPR) of specimen is considered for experimental works in the range of 0.6 to 0.8. A new deflection model is recommended in the present study considering the strain contribution of CFRP bar and steel reinforcement for the fully bonded member. New deflection model converges to experimental results with the error of less than 5% .