Semesta Teknika

Analysis of Stakeholder’s Understanding of Green Roads Principles in Construction of Yogyakarta-Bawen Toll Road Section I

2024-12-06T10:06:56+07:00

Infrastructure plays a vital role in economic development. Apart from having a positive impact, infrastructure development also has negative impacts such as global warming and reduced availability of natural resources. Therefore, a sustainable approach must be applied in construction projects, especially road construction. Considering the lack of awareness regarding implementing sustainable construction, this research aims to analyze the level and differences in stakeholder understanding regarding green roads in the Jogja – Bawen Toll Road construction project (section 1). This research uses a quantitative approach which uses primary data as the main data. Primary data was obtained through filling out questionnaires by respondents consisting of owners, consultants and contractors involved in the Yogyakarta-Bawen Toll Road Project (section 1). Based on data analysis, it can be concluded that the owner and contractor understand all the principles of sustainable construction, while the consultant only understands social and environmental principles.

A Bibliometric Review of the Dam Construction Impact

2024-12-06T10:06:56+07:00

Dams are crucial constructions for managing water supplies. However, the detrimental environmental effects of dam development have also drawn criticism. The influence of dam construction over the past fourteen years and new research trends are included in this study. This study aims to determine how many papers have been produced, how productive researchers are, and chart the evolution of dam impact publications. The analysis showed that 1312 publications related to the topic discussed were generated. The findings demonstrated that engineering and environmental studies were the main focus of research trends concerning the effects of dam development. This study provides an overview of the trends in the direction of existing literature for future research, and evaluation of research topics through existing topic clusters. China, the USA and the United Kingdom are the three leading countries in dam construction impact research in terms of publications.

Mechanical and Physical Properties of Cement Mortar with Recausticizing Solid Byproduct

2024-12-06T10:06:56+07:00

The Kraft process is a method used to make paper pulp. This method produces cooking residue that can be recycled again. The recausticizing process produces large amounts of by-products.This research utilizes solid waste from causticizing from the pulp industry as a partial substitute for Portland cement for mortar raw material to obtain a material with good mechanical properties. The solid waste was pulverized, then characterization of Loss on Ignition (LOI), Inductively Coupled Plasma (ICP), Titration, and Total Titrable Alkali was carried out. The percentage of solid waste resulting from recausticizing as a substitute for cement is 0-100%, with a water-cement ratio (w/c) of 0.3. The mixed material is then printed into a 50x50x50mm mold followed by drying using the moist curing method. The hardened samples were tested for Density, Porosity, Water Absorption, and Compressive Strength. Mortar with partial cement replacement with 20-100% solid waste recousticizing produces a compressive strength of 1.3-22.6 MPa. The resulting water absorption ranges from 14.59-31.35%.

Recycled PET Plastics Filament: Characteristic and Cost Opportunity

2024-12-06T10:06:56+07:00

Piyungan Integrated Waste Disposal Site (TPST) is a waste disposal site in Yogyakarta province. With an estimated increase in the amount of waste of 8% per year, it is estimated that the TPST will not be able to accommodate waste from the community. One of these wastes is PET bottle. This research aims to develop a new recycling method by converting PET plastic waste into 3D Printer machine filament and investigate the opportunity of this PET filament. This research uses several stage methods: PET filament making, Tensile test, macroscopy photography and opportunity analysis. This study concludes that PET bottle waste can be used as 3D printer filament with a diameter of 1.7 mm. Processing PET bottle waste into 3D printer machine filament can increase the economic value of PET bottle waste. And this can contribute to the potential for processing plastic bottle waste.

FTA Method: Analyzing Factors That Influence the Development of OAP SMEs

2024-12-06T10:06:56+07:00

The poverty level in Southwest Papua, especially in the city and district of Sorong, is much higher than other areas in Southwest Papua, so small and medium enterprises (SMEs) owned by indigenous Papuans play an essential role as economic drivers. The urgency of this research is to develop indigenous Papuan businesses, which have been challenging to grow, so they must know what factors are needed to create. Several factors influence business development: capital, skills and knowledge, market access, and government support. To compete with developing Orang Asli Papua (OAP) businesses, they will be able to compete with non-OAP businesses and overcome poverty in Southwest Papua Province. This research uses the Fault Tree Analysis method to analyze the factors that influence the development of OAP SMEs. The research results show that six priorities are the main factors for developing SMEs: Education and Training, Networks and Connections, Capital Assistance, Marketing Skills, infrastructure and the role of government.

Modeling’s Effect of Irregular Building Structure with Vegetated Roof on Seismic Evaluation per ASCE 41-17

2024-12-06T10:06:56+07:00

This study examines the seismic vulnerability of an irregular educational building with a vegetated roof in Yogyakarta using linear procedures based on ASCE 41-17. Modelling approaches differ Model 1 treats skylights and planter boxes as loads with straight roof slabs, while Models 2 and 3 use shells with sloping roof slabs. Vegetated roofs are featured in Models 1 and 2. The analysis, conducted at seismic hazard levels BSE-1N and BSE-2N using the ETABS program, evaluates structural components and compares Response Spectrum (RS) and Linear Time History (LTH) methods. Results show seismic weight variations of 1.20% to 15.04% between models. Model 1 fails to meet the criteria for modal analysis, while Models 2 and 3 do. The structural performance evaluation based on average demands at BSE-1N and BSE-2N levels varied from Immediate Occupancy to Life Safety performance. The LTH method in all models had higher acceptance ratios than the RS method.

Evaluation of Public Buildings as Tsunami Evacuation Vertical Based on Tsunami History

2024-12-06T10:06:56+07:00

The research method was carried out through a survey of a number of buildings in the coastal area of Banda Aceh City. The analysis was carried out by comparing the floor heights of buildings with the historical height of the tsunami that occurred in 2004. Based on the survey results, it was found that there were 319 public buildings spread across the coastal area of Banda Aceh City. The percentage of each is known by the number of government office buildings (31.7%), educational facilities (40.8%), health services (5.6%), places of worship (16.6%), trade (2.2%), and other facilities (3.1%). From the analysis of building floor heights, a total of 194 buildings, or 60.81% of the total existing public buildings could function as alternative vertical evacuation sites for the tsunami disaster. This amount can accommodate 43.95% of the total population living in the surrounding area. Thus, part of the population can carry out vertical disaster evacuation. While others are planned through horizontal evacuation scenarios. Public buildings designated as vertical evacuation sites are only calculated from the safe height of the building floor. In contrast, in terms of the resilience of the building structure, it can be re-evaluated.

Integration of RISHA and Eco-Damper Prevents Earthquake Damage to Houses

2024-12-06T10:06:56+07:00

This research introduces an eco-damper building concept integrating Simple Healthy Instant House (RISHA) technology with reclaimed vehicle tires to enhance earthquake resistance in Indonesian residential buildings. Many earthquake-resistant building designs currently focus on structural reinforcement but overlook sustainable materials and cost-effectiveness, creating a gap in addressing environmental and disaster resilience. This study addresses this gap through a literature review and a conceptual design approach, identifying RISHA technology's strengths, limitations, and potential applications combined with eco-damper systems. The research found that integrating RISHA and recycled rubber from vehicle tires offers a comprehensive solution that enhances earthquake resistance while promoting sustainability and energy efficiency. The eco-damper system introduces a novel approach compared to earthquake-resistant technologies and contributes positively to environmental preservation by utilizing waste materials. However, one of the identified challenges is ensuring consistent material quality from used tires and the need for proper disposal or repurposing of other waste materials associated with this method. This study significantly contributes to disaster risk reduction in Indonesia. At the same time, the eco-damper concept also shows potential scalability for use in other earthquake-prone regions, offering a sustainable and adaptable solution.

Design of a Corn Thresher and Corn Cob Chopper Using the Pahl & Beitz Method

2024-12-06T10:06:57+07:00

The manual corn threshing process by farmers can slow down the processing and subsequent rotation of corn and affect the quality of the corn. In addition, waste from corn processing is not utilized correctly, so processing is needed. This study aims to design a corn threshing tool and corn cob shredder and to make the processing time more efficient so that the productivity and economy of farmers increase. The design method used is Pahl & Beitz, with four stages: planning and explaining tasks, designing product concepts, designing product shapes and details. The most recovered concept was produced based on the design method: concept variant 2. The corn threshing tool and corn cob shredder designed with a 240 kg/hour capacity can make the processing time more efficient. This is known from the results of testing. The tool can thresh 4 kg of corn in 1 minute, and corn cob waste is automatically chopped into powder that can be used as animal/poultry feed.

The effect of welding time on the tensile load capacity of dissimilar-metal stainless steel-carbon steel TIG-Spot welded joint

2024-12-09T10:11:44+07:00

This study examines the influence of welding time on the tensile load capacity of spot TIG welds using stainless steel and low carbon steel plates (100 mm × 30 mm × 0.8 mm) as per AWS D8.9 standards. A constant welding current of 90 A was applied, with 2-, 3-, 4-, and 5-seconds welding times. Tensile properties, microstructure, and hardness were analyzed using a universal tensile machine, an optical microscope, a scanning electron microscope, and a Vickers hardness tester. Results show that the tensile load capacity increases with welding time, peaking at 4 seconds (≈4300 N), before dropping significantly at 5 seconds (≈4000 N) due to overheating, which weakens the joint. The findings highlight the critical role of optimizing welding time to maximize joint strength while preserving the material's microstructure. Overextended welding times compromise performance, emphasizing the balance required for achieving durable welds.