Andreas Triwiyono

Effects of Bolt Distance on Flexural Behavior of Bolt-Laminated Bamboo Beam

Bolt-laminated bamboo beam was utilized as an alternative to replace wood and it was used as structural and non-structural construction material. Bamboo material then has become the most popular non-wood material in construction field. Nowadays, bamboo material is not optimally utilized yet. Many studies showed the advantages of bamboo to be compared to the other materials. The diameter of Gigantochloaatroviolacea bamboo used in this study is ranged from 70 to 90 mm. The diameter of bolt is 12.7 mm. The improvement of strength and bending stiffness of beam can be conducted by arranging the full-culm bamboo with bolt as the shear connector. Variations of bolt distance in this study were 125 mm, 250 mm and 500 mm. The final product of the bamboo jointed segment is bolt-laminated bamboo beam. Setup test for bolt-laminated bamboo bemuses four point bending method. The strength and bending stiffness of boltlaminated bamboo beam has increased as the bolt distance decreased.The shear connector distance that are greater than 500 mm has no significant affect to the strength and bending stiffness of the beam. Therefore, the distance of bolts is suggested to be less than 500 mm.

Seismic Performance of the King Cross Steel Profile in Interior Reinforced Concrete Beam-column Joint

The high amount of steel bar reinforcement in beam-column joints causes congestion problem. Here, king cross steel profile, as an alternative to shear reinforcement in the joint of reinforced concrete beam-column, is proposed. This is achieved by simplifying the assembly of king cross steel profile implants at beam-column joints as a shear reinforcement, which could be expected to replace the transversal reinforcement and enhance the joint shear strength. Two sets of interior beam-column joint subassemblies with stirrup reinforcement (SJ) and with king cross steel profile reinforcement (KCJ) as the shear reinforcement in the joint were studied. The experimental result concluded that the average peak load of SJ specimen was higher than that of KCJ. However, KCJ had good performance and contributed to the shear strength of the joint. The performance and contribution of KCJ can be seen from the load carrying capacity above 6.7% in the positive direction and below 24.91% in the negative direction compared with SJ. The pattern of the crack occurred showed a severe failure in the joint panel of KCJ. In this study, the width of the web was twice that of the flange, but in future studies, the width should be enlarged until it sufficiently fills the entire joint section and the width of the web is about six times of the flange. This web enlargement and flange reduction were performed by considering the area of a cross-section of the king cross profile and the requirement of shear capacity of the joint installed. It was done to increase the shear strength of the interior beam-column joint subassemblies with KCJ.

Cost Estimation Model for I-Girder Bridge Superstructure Using Multiple Linear Regression and Artificial Neural Network

One of the owner’s common problem before executing construction projects is the complexity in estimating the project cost in an early stage. Inaccurate cost estimation will force the owner to make further arrangement to the project budget. This study aims to develop an initial cost estimation model for superstructures of Precast I-girder Bridge. Cost estimation model was developed based on thirteen data of detail engineering design of I-girder bridge in Daerah Istimewa Yogyakarta (DIY). Factors influencing the cost of the superstructures of the I-girder bridge were identified. Bridge span and width, the size of the sidewalk, and railing’s type are considered as variables affecting the cost of superstructures. These variables are then arranged into two different analysis Multiple Linear Regression (MLR) analysis and Artificial Neural Network (ANN), in order to obtain the best estimation model. The results of the analysis showed that bridge span and width were the significant factors influencing cost. The correlation value of bridge span is 89.0%, bridge width is 74.2%, the size of the sidewalk is 66.1%, and railing’s type is 46.1% as identified factors that affect the cost of the superstructure. A comparative model of two approaches shows that the ANN has better accuracy than that of MLR, although the difference was not significant.

The Damping Mechanism of Steel-Rubber Composite Beam under Flexural Dynamic Excitation

Damping is one of the several important parameters in the dynamic system. It reduces amplitude response of a structure, especially around the resonance. The higher the damping, the better the performance (more comfort, lower stress, less fatigue), and the longer the life cycle of the structure will be. There are many types of damper amongst other is the tuned mass damper (TMD), where mass and spring are designed in such that the TMD frequency is close to the natural frequency of the structure in question where the phase angle is about 180 degree out of phase. Applying steel-rubber composite beam as a damper in the TMD system is expected to increase the damping of the structure of interest. The objective of this study is to test experimentally and numerically the dynamic parameters of the rubber-steel composite beam upon a cantilever support system under static load-displacement test and flexural dynamic excitation. The addition of steel (in the form of wire mesh) embedded in the rubber beam significantly increases the stiffness, but the damping ratio, at a small range of displacement. The effectiveness of rubber material in the steel-rubber composite beam is expected when large displacement occurs, meaning that more energy dissipation and larger damping ratio. The established numerical model is able to generate dynamic parameters close to results of the experimental model, but the damping ratios.

Structural Condition Assessment of Steel-Framed Maintenance Plant in Muara Badak, Balikpapan, East Kalimantan

Structural condition assessment was conducted to a single-story, steel-framed maintenance plant. The assessment procedure aimed to ensure safe and sound operation of the existing structure, to determine its remaining service life as well as to propose the appropriate remedial actions for the existing structure. The assessment was performed through visual observation, Non-Destructive Testing (NDT), field load testing, also by carrying out structural analysis upon verified structural model. Corrosion and buckling are the main types of deterioration found within the structure owing to high salinity and slender steel sections. Structural analysis gave maximum stress ratio of 0.374. Static load testing resulted in deflection value of 17 mm, while dynamic load testing resulted in dynamic amplification factor of 1.06. In conclusion, the existing structure is considered to be structurally safe and sound with remaining service life of approximately 36 years and subjected to structural maintenance and strengthening.

Experimental Investigation on the Flexural Performance of Brick Masonry Wall Retrofitted Using PP-Band Meshes under Cyclic Loading

Numbers of residential houses were damaged in some areas caused by earthquakes. The damages greatly affected the number of losses. Most of the houses in some countries are made of brick unreinforced masonry (URM) walls. Improving the structural performance of this kind of masonry has become important. For this reason, experimental study was conducted on the flexural performance of brick walls retrofitted with strapping band (polypropylene/pp-band). The walls were constructed using bricks produced manually with joint mortar ratio of 1 PC: 6 sand, that chosen to represent the actual field conditions of the communities in Indonesia. The aims of the study were to determine the out of plane flexural performance of the non-retrofitted and retrofitted brick masonry walls under cyclic loading by using some variations of the distance between pp-band. The walls were loaded to produce flexural bending that caused vertical and horizontal cracks. The results of the test showed that the retrofitted walls failed by large deformation. After crack, the strength reduced to about 25-50% of the crack load and then regained progressively as residual strength until 150% higher than the strength at crack load by large deformation due to the strapping band mesh. The wall with 10 cm pp-band distance should be used as optimum solution for retrofitting

Experimental and Theoretical Investigation of Bolted Bamboo Joints without Void Filled Material

An experimental and theoretical are presented to calculate the load capacity of shear single connection (SSC) and shear double connection (SDC) without void filled material. The model presents an extension of the Johansen theory for bamboo connection type, also known as the European Yield Model (EYM). The bamboo of Gigantchloa atroviolacea of the most popular as non-wood has been used as a construction material in some region of Indonesia. The uniqueness bamboo is bamboo non-homogen material, sectional shape non-prismatic, the straighthness stems not same, on the culms guiler node and a cross-section in hollow. The diameter of Gigantochloa atroviolacea bamboo used in this study is ranged from 70 to 90 mm. The diameter of bolt is 12.7 mm. The connection strength can be determined with theoretical and eksperimental. Application theory of the European Yield Model could be developed into theory of connection laterally strength of bamboo without void filler material. Factors that affected of connection laterally strength is bamboo thickness, bolt diameter and spesific gravity. The equation four of connection strength base on European Yield model can calculated of according to yield model of accurred. The connection strength is specified from the value smallest of the equation four of connection yield models.