SAUNG BAMBU KOMPOSIT DENGAN SAMBUNGAN PELAT BUHUL

Bamboo can be used to make all building components, both structural and non-structural. The construction of this bamboo building is characterized by a structural framework approach similar to that applied in wooden construction. In this case, the floor, wall and roof elements are interconnected and interdependent on each other for overall stability. There is a need to control lateral deformation in some traditional forms of buildings in particular. The adequacy and suitability of the building for housing will also depend on good details. In the use of bamboo as a structural element, various types of connections are known which are often applied in various types of buildings. The types of connections are double butt bent joints, friction-tight rope connections, plug ins, positive fitting connections, and interlocking connections. These types of joints are not very strong and cannot withstand excessive loads in various directions because the surface area of the connection is very small and bamboo has cavities. This connection will not last long if it is used as a connection to the truss or bridge truss. This connection is not very strong. In the Cipete Village area, Pinang District, Tangerang City, there are still many buildings that use bamboo as a structural element, both for housing, selling places, and huts for resting. The bamboo connections in these buildings still use traditional grafting techniques, so the buildings quickly become damaged and the community pays more to repair them. The Community Service Team (PKM) of the Civil Engineering Undergraduate Study Program helps the community provide bamboo splicing technology to increase the service life of bamboo buildings by improving bamboo grafting techniques. The splicing technique is done by expanding the surface of the connection, namely making the bamboo solid in the bamboo area. In addition to making the bamboo solid in the joint area, gusset plates and bolts are also used to strengthen the connection. Bambu dapat digunakan untuk membuat semua komponen bangunan, baik struktural maupun non struktural. Konstruksi bangunan bambu ini ditandai dengan pendekatan kerangka struktural mirip dengan yang diterapkan dalam konstruksi kayu. Dalam hal ini, elemen lantai, dinding dan atap saling dihubungkan dan saling bergantung satu sama lain untuk stabilitas keseluruhan. Ada kebutuhan untuk mengontrol deformasi lateral dalam beberapa bentuk tradisional bangunan pada khususnya. Kecukupan dan kesesuaian bangunan untuk hunian juga akan tergantung pada detail yang baik. Dalam pemanfaatn bambu sebagai elemen struktur, dikenal berbagai jenis sambungan yang sering diaplikasikan dalam berbagai jenis bangunan. Jenis-jenis sambungan tersebut adalah double butt bent joint, friction-tight rope connection, plug in, positive fitting connections, dan interlocking connection. Jenis-jenis sambungan tersebut tidak terlalu kuat tidak mampu menahan beban yang berlebih dalam berbagai arah meningat karena luas permukaan sambungan sangat kecil dan bambu memiliki ronga. Sambungan ini tidak akan bertahan lama bila digunakan sebagai sambungan pada rangka kuda-kuda atau rangka jembatan Sambungan seperti ini tidak terlalu kuat. Didaerah Kelurahan Cipete, Kecamatan Pinang Kota Tangerang, masih banyak bangunan yang memanfaatkan bambu sebagai elemen struktur, baik untuk perumahan, tempat berjualan, maupun saung-saung tempat istirahat. Sambungan bambu pada bangunan-bangunan tersebut masih menggunakan Teknik penyambungan tradisional, sehingga bangunan tersebut cepat menjadi rusak dan masyarakat mengeluarkan biaya lebih untuk memperbaikinya. Tim Pengabdian Kepada Masyarakaya (PKM) Program Studi Sarjana Teknik Sipil membantu masyarakat memberikan teknologi penyambungan bambu untuk meningkatkan umur layanan bangunan bambu dengan memperbaiki teknik penyambungan bambu. Teknik penyambungan dilakukan dengan memperluas permukaan sambungan yaitu membuat bambu menjadi solid didaerah bambungan. Selain membuat bambu menjadi solid didaerah sambungan, juga digunakan pelat buhul dan baut untuk memperkaku sambungan.

Assessment of Provisions for Load Rating Gusset Plates in Steel Truss Bridges

Many states have load rated their truss bridge gusset plates following the guidelines published in 2009 by the Federal Highway Administration in response to the catastrophic failure of the I-35W Bridge. As the Manual of Bridge Evaluation released new load rating provisions after 2014, the urgency in adopting and applying these mandated provisions became a pending burden for state agencies requiring extensive work to update the ratings of gusset plates. Moreover, this paper argues that the current states’ load rating practices do not involve the rating for the welded gusset plate owing to the lack of established provisions. In addition, the gusset plate with no plans also poses particular challenges for the state agencies. To provide state agencies with better insights on the load rating approach of gusset plates, this paper presents a study that carefully reviewed the states’ current practices and load rating provisions. The results of the study indicate the necessity of adopting the new provisions, as the former load rating methodology exhibited inaccurate results in some cases. Additionally, this paper reviews extensive work done for welded connections and proposes a load rating guidance for welded gusset plates. To deliver better interpretations, a case study is provided for the welded gusset plates. This paper also reviews the evaluation method for deteriorations and staggered bolt patterns with relevant case studies. Lastly, the paper provides guidance on estimating the unknown bolt strength as well as weld metal strength for the gusset plate.

Pilot Demonstration of a Strengthening Method for Steel-Bolted Connections Using Pre-Formable Carbon Fiber Cloth with VaRTM

In recent years, many seismic retrofitting methods have been performed to improve the structural performance and prevent the brittle failure of structural members. In the case of steel structures, slender seismic braces have been widely used for buildings, towers, and bridges. The brace connections should resist the full plastic axial tension load to ensure adequate plastic deformation performance for vibration energy absorption. However, certain connections do not satisfy these requirements. Recently, carbon fiber reinforced plastic (CFRP) has been used extensively to strengthen existing structures because of its high-strength, high elastic modulus, and light-weight characteristics. In this paper, we investigate the applicability of CFRP strengthening for brace connections and gusset plates with stepped surfaces using the vacuum-assisted resin transfer molding technique as a pilot demonstration. Stepped surfaces can be eliminated by using alternative CFRP layers to straighten the structural CFRP layers in order to effectively transfer the axial stress. Eventually, it is shown that CFRP strengthening can improve the connection strength and plastic deformation with 3% elongation, even if the CFRP is molded on the stepped surface.

BEARING STRENGTH OF SHEAR CONNECTIONS FOR TUBULAR STRUCTURES: AN ANALYTICAL APPROACH

This work deals with the prediction of the bearing resistance of elementary shear connections constituted by gusset plates and square hollow sections fastened with long bolts. The research is motivated by the lack of specific rules in international codes for this particular configuration. In fact, while in lap shear connections, single or double-sided, the holes are always confined out of plane, in case of connections with long bolts and gusset plates (typical of tubular structures), the holes are constrained out of plane outwards, but they are free to buckle inwards, providing a reduction of the bearing strength. Within this framework, the paper is aimed at the development of an analytical formulation for the prediction of the bearing resistance of connections with long bolts and square hollow sections (SHS). The proposal is based on the calculation of the post-buckling load of the tube plate subjected to bearing at the bolt hole, combining the Winter's formula (originally developed to predict the post-buckling strength of steel plates accounting for geometrical and mechanical imperfections) with a simplified FE model developed in SAP 2000. The procedure developed is presented in detail proposing a design equation for connections with long bolts, based on a formula suggested recently by Može (2014, 2016) suitable for the inclusion in code provisions such as EC3. The accuracy of the design equation is checked on the experimental data reported in a previous work of the same authors properly extended with parametric FE simulations to cope for variation of geometrical parameters.

Construction of All-Wood Trusses with Plywood Nodes and Wooden Pegs: A Strategy towards Resource-Efficient Timber Construction

Timber truss systems are very efficient load-bearing structures. They allow for great freedom in design and are characterised by high material use in combination with a low environmental impact. Unfortunately, the extensive effort in design and production have made the manufacturing and application of these structures, in this day and age, a rarity. In addition, the currently mainly used steel gusset plates adversely affect the costs and environmental impact of the trusses. The authors’ goals are to optimise the design of timber trusses and to solely use wood for all building components. The two research areas, (1) optimisation of the truss geometry and (2) optimisation of the joints by using solely wood–wood connections, are addressed in this paper. The numerical optimisation strategy is based on a parametric design of the truss and the use of a genetic solver for the optimisation regarding minimal material consumption. Furthermore, first results of the tensile and compression behaviour of the chosen wood–wood connections are presented. The basic idea for the joints is to use a plywood plate as a connector, which is inserted into the truss members and fixed with wooden pegs. The housing of the new robot laboratory located at BOKU Vienna is considered a special case study for the research and serves as an accompanying example for the application of the research within the present paper.