Publication Search

The rapid growth of the business world is forcing companies to adopt automation and efficiency to survive and compete. PT. Varia Usaha Beton, a concrete manufacturer, relies heavily on an accounting system for raw material purchasing to ensure efficient operations. The purpose of this research is to evaluate the company's raw material purchasing accounting system, identify problems and recommend improvements. The research method used is descriptive and qualitative with a case study approach. Primary data was obtained through interviews and observations, while secondary data was obtained through company documents. The research results show that the system works well and supports cost control, inventory management and quality monitoring. However, there are several vulnerabilities such as human error, technical issues with the ERP system, and weather-related delays in shipping raw materials. Recommended improvements include improved employee training, optimizing the ERP system, and developing more efficient inventory management. This research provides insights into the importance of evaluating accounting systems to improve the efficiency and effectiveness of business operations. Further research is recommended to conduct comparative analysis with other companies and explore new technologies to increase purchasing management transparency and efficiency

This study aims to redesign the superstructure of the Sambungrejo Bridge in Sidoarjo, which has a span length of 16 meters. The Sambungrejo Bridge originally used WF 700.300.15.28 steel girders and C 300.100.10.16.8 diaphragms,that are susceptible to corrosion, especially during floods. The redesign involves replacing the steel girder with a Prestressed Concrete I Girder (PCI Girder) H-900mm, 170mm thick, produced by WIKA Beton, known for its superior corrosion resistance and construction efficiency. The research methodology includes structural analysis using Robot Structural Analysis Professional (RSAP) software, calculation of prestressing forces, and the design of the prestressing cable layout. The results of this study demonstrate that the use of PCI Girder does not reduce the structural dimensions of the bridge but also proves to be more compatible with the flood water conditions at the site. The total cost required for implementing the new bridge superstructure design is Rp. 4.372.201.

Concrete typically consists of coarse aggregate, fine aggregate, cement, and water. However, cement production generates significant carbon dioxide emissions nearly equivalent to the tons of cement produced. One alternative to conventional concrete, which replaces cement as a binder, is geopolymer concrete. Geopolymer concrete utilizes fly ash or other materials containing silica and alumina as the binder. Unlike cement, which forms a binder through hydration, geopolymer concrete uses a chemical reaction with alkali activators such as Na2SiO3 (sodium silicate) and NaOH (sodium hydroxide). This study investigates the toughness of geopolymer concrete using cylindrical specimens measuring 15 cm x 30 cm with varying Na2SiO3 to NaOH ratios of 1:0.5, 1:1, and 1:1.5, cured at room temperature for 28 days. The study results show that the highest toughness was achieved with a sodium silicate to sodium hydroxide ratio of 1.5, yielding 2.7394 x 105 J/m3. Meanwhile, the toughness values for sodium silicate to sodium hydroxide ratios of 0.5 and 1.0 were 2.3748 x 105 J/m3 and 2.5821 x 105 J/m3, respectively. Thus, increasing the sodium silicate to sodium hydroxide ratio from 0.5 to 1.5 at an activator content of 0.43 affects the toughness of geopolymer concrete.

Infrastructure development contributes to increasing the competitiveness of domestic products, employment energy absorption, and regional growth. Therefore, a strong, rigid and stable construction is needed. The use of materials for construction needs to be considered, especially commonly used materials such as concrete. This research aims to analyze the effect of variations in granite content as a partial substitution for coarse aggregate on the bond strength of BRA (Concrete Recycled Aggregate) concrete. Experimental methods were used in this research. The concrete mix design uses a variety of granite waste with a content of 0%; 15%; 30%; and 45%. The test object used was a concrete cube with a side length of 20 cm. The bond strength of the concrete is tested using a Universal Testing Machine (UTM) and a dial gauge. Based on research, the maximum bond strength value is obtained at a granite content of 30%. The addition of granite waste causes an increase in the bond strength value. The bond strength value of concrete when slip occurs is 0.25 mm at 0% granite content; 15%; 30%; and 45% each valued at 14.61 MPa; 15.44 MPa; 18.62 MPa; and 17.15 MPa. Concrete bond strength value at maximum load at 0% granite content; 15%; 30%; and 45% each valued at 22.42 MPa; 22.59 MPa; 24.01 MPa; and 23.12 MPa.

The background of this research focuses on the importance of OHS in the manufacture field, especially considering the high number of work accidents reported by BPJS Ketenagakerjaan. This research aims to identify and assess the risk of hazards at PT Bumi Sarana Beton using Hazard Identification Risk Assessment Determining Control (HIRADC) and provide solutions to reduce work accidents. The HIRADC method is used to identify hazards, assess risks, and determine appropriate controls in accordance with the AS/NZS 4360: 2004 standard. The results showed that the production work area has several high risks such as pinching, respiratory distress, and slipping. Effective risk control implementation is expected to improve work safety and productivity. These findings have important implications for the management of PT Bumi Sarana Beton to improve OHS policies and provide adequate training and protective equipment for workers. In addition, this research is also expected to be a reference for other industries in implementing OHS optimally to reduce the risk of work accidents and improve workers' welfare

Increased economic growth in the city of Parepare with the presence of buildings around the estuary. In general, the composition of concrete making materials is taken from good materials. The problem encountered in the field is that the quality of concrete in construction decreases due to brackish water, causing structural elements in the construction to become porous. Meanwhile, preventive measures are rarely or never taken. As a result, the construction life is very short. Brackish water is one of the causes of structural failure. This is due to the content of sulfate and chloride ions in water containing salt/salts that react with chemical elements in reinforcing steel resulting in corrosion of the reinforcement. The purpose of the study was to analyse the compressive strength of concrete with a mixture of clean water against the percentage of brackish water with a maintenance age of 7, 14, 21, and 28 days. The results showed that brackish water had an impact on reducing the compressive strength of concrete due to the high chemical content in brackish water such as Sulfate (SO²¯) of 52.5 in brackish water in Kenjeran and 62.5 in brackish water in mangrove. Dissolved Solids (TDS) of 15188 mg/l in kenjeran brackish water and 3436 mg/l in mangrove brackish water. Organic Content (KMnO) of 8.05 mg/l in kenjeran brackish water and 6.69 mg/l in mangrove brackish water is too high, so the chemical content contained in brackish water can damage the compounds in the cement content and decrease the strength of the materials contained in the concrete. In this case it can result in concrete having a very low durability.

Currently, infrastructure development is a priority of the Indonesian government which aims to improve the quality of life of the community and equitable distribution of infrastructure development. The need for concrete material as a construction material also increases in line with the increase in infrastructure development. The use of recycled aggregate materials, especially granite waste, is a promising option in sustainable infrastructure development. This study was conducted with the aim of knowing the effect of partial substitution of coarse aggregates using granite waste variations on the binding time and permeability of concrete. Experimental method was chosen in this research. The levels of granite waste used were 0%; 15%; 30%; and 45% by weight of coarse aggregate or gravel. The test specimens used for the concrete bond time study were fresh concrete poured into cube molds measuring 20 cm x 20 cm x 20 cm with a minimum height of 15 cm. Testing concrete bond time using a penetrometer tool. The test specimen for concrete permeability is a cube measuring 15 cm x 15 cm x 15 cm, totaling 12 pieces and tested with a Permeability Test Apparatus (Water Permeabilty Apparatus).The results showed that partial substitution of coarse aggregate with granite waste variation did not affect the setting time of concrete up to a certain level. Based on the results of the research conducted, the initial setting time and final setting time values of 0%, 15%, 30%, and 45% granite content variations fluctuate and the coefficient of determination (R2) value in linear regression is only 0.5 and 0.3. Partial replacement of coarse aggregate with granite waste has an effect on the impermeability of concrete which meets the requirements for medium aggressive impermeable concrete. Water pressure of 5 kg/cm2 for 72 hours applied to the concrete partial replacement of coarse aggregate with granite waste variation resulted in permeability coefficient values of 4.11 x 10-12 cm/s; 3.48 x 10-12 cm/s; 2.17 x 10-12 cm/s; and 3.25 x 10-12 cm/s. The minimum coefficient value of concrete with partial substitution of coarse aggregate with granite waste is obtained at 30% by weight of coarse aggregate. Granite, whose specific gravity is greater than gravel, produces denser and more water-resistant concrete.     

Concrete is one of the most common construction materials used throughout the world. Concrete consists of three main components: cement, coarse aggregate, and fine aggregate. Coarse aggregate serves as the main structural component in concrete, providing strength and resistance to external loads. Currently, technological advancements in construction are rapidly progressing. Therefore, innovation in concrete production is necessary, one of which is recycled aggregate concrete. The aim of this research is to determine the effect of using granite waste as a partial substitute for coarse aggregate on toughness of concrete. The method used in this research is experimental method. In this study, the variation level of granite waste used in this study was 0%; 15% ; 30% ; and 45%. The objects used for this research are blocks with dimensions of 400x100x100 mm tested using a Universal Testing Machine. The results of this research show that the toughness value obtained from the results of toughness testing on concrete with varying levels of 0% granite waste; 15% ; 30% ; and 45% respectively, namely 1.9589 kNmm; 2.2362 kNmm; 2.4189 kNmm; and 2.2118 kNmm.

The development of concrete making technology has developed rapidly nowdays, the innovations in terms of material use and workmanship. The implementation of construction work carried out today pays attention to aspects of strength, rigidity, and high durability, as well as sustainability. To support these two things, research can be carried out on making concrete using granite waste. The research method used in this study is an experimental method. The concrete mix design uses variations of granite waste with successive levels of  0%, 15%, 30%, and 45%. The test specimen used for tensile strength testing is cylindrical with a diameter of 15 cm and a height of 30 cm, the test uses 12 specimens where each variation uses 3 specimens. The test is performed when the specimen has reached the age of 28 days. The test specimen tested has met the planned compressive strength requirements at a concrete life of 28 days where the results are greater than 20 MPa. Results of testing the tensile strength of concrete variations of granite waste as a partial substitution of coarse aggregate with variations of granite waste of 0%, 15%, 30%, and 45% respectively; 2.43 MPa; 2.50 MPa; 2.97 MPa; and 2.78 MPa.

Gelombang elektromagnetik merupakan perpaduan dari medan listrik dan medan magnet. Gelombang elektromagnetik dapat merambat melalui atau tanpa adanya medium ambat. Medan magnet Extremly Low Frequency memiliki frekuensi < 300 Hz. Dengan frekuensi yang rendah ini, membuat gelombang ELF mampu menembus beberapabahan diantaranya tanah, air hingga beton dengan baik. Salah satu manfaat dari gelombang ELF yaitu dapat dimanfaatkan untuk mengawetkan bahan pangan. Bahan pangan yang sering dijumpai, kerap memiliki daya tahan atau masa simpan yang terbatas, gelombang ELF ini dapat dimanfaatkan untuk menambah daya tahan atau masa simpan bahan makanan seperti tempe, buah buahan dan juga ikan. Medan magnet ELF (dapat memperpanjang masa simpan ikan dengan cara menjaga pH ikan. Mekanisme ELF dalam menambah daya simpan ikan yaitu dengan cara menajaga atau mempertahankan pH ikan agar daya simpannya semakin lama tanpa merusak fisik ikan sehingga masih layak konsumsi. Metode yang dilakukan pada penelitian kali ini yaitu study literatur. Study literatur dilakukan dengan mengumpulkan berbagai macam sumber literatur baik nasional maupun internasional yang digunakan untuk mencari data dan hasil penelitian. Dari data data yang diperoleh dalam litertaur dapat ditarik kesimpulan dimana gelombang elektromagnetik Extremly Low Frekuensi dapat menambah usia simpan ikan dengan  mempertahankan pH sehingga mikroba tidak mudah berkembang biak.

Penanganan limbah adalah suatu keharusan karena limbah dapat memiliki dampak negatif yang signifikan terhadap lingkungan, kesehatan manusia, dan keberlanjutan. Beberapa limbah dapat didaur ulang atau diproses kembali untuk menghasilkan bahan baku yang dapat digunakan kembali. Dengan menangani limbah dengan benar, kita dapat mengurangi kebutuhan akan bahan baku alam baru dan mendukung konservasi sumber daya. Mengetahui karakteristik dan nilai kuat  tekan  beton  dengan  penggantian  sebagian  agregatnya  dengan agregat daur ulang yang berasal dari limbah batu bata penggaron adalah tujuan dari penelitian ini.  Urgensi  dari  penelitian  ini  adalah  menghadirkan  solusi  untuk  mendaur ulang limbah batu bata penggaron hasil pembongkaran konstruksi dan sisa produksi batu bata sebagai pilihan pengganti agregat  kasar alam dalam campuran beton yang juga diharapkan mampu menjadi salah satu penerapan yang dapat mendukung adanya program green concrete. Hasil penelitian menunjukkan bahwa proporsi optimal untuk penggunaan bata Penggaron sebagai pengganti agregat kasar adalah sebesar 60% dari total kebutuhan agregat kasar dalam desain.

Produktivitas Batching Plant merupakan faktor kunci dalam menentukan efisiensi dan keberhasilan proyek konstruksi. Penelitian ini dilakukan untuk menganalisis produktivitas Batching Plant di PT. Merak Jaya Beton, dengan fokus pada Batching Plant KarangPilang, selama bulan September dan Oktober 2023. Metode penelitian melibatkan pengumpulan data primer melalui observasi dan wawancara langsung di lapangan, serta pengumpulan data sekunder dari informasi perusahaan. Produktivitas Batching Plant diukur dengan menggunakan rumus produktivitas berdasarkan volume beton yang diproduksi dalam suatu periode waktu. Hasil analisis menunjukkan bahwa produktivitas Batching Plant KarangPilang mencapai rata-rata sekitar 26 m³/jam selama kedua bulan tersebut. Meskipun berada di bawah batas maksimum harian yang dapat dicapai, yaitu 60 m³/jam, produktivitas tersebut masih mencapai sekitar 44,08% dan 43,53% dari batas maksimum pada bulan September dan Oktober, berturut-turut. Faktor-faktor yang memengaruhi fluktuasi nilai produktivitas harian melibatkan penyesuaian jadwal pengiriman berdasarkan permintaan dari pihak proyek. Penelitian ini memberikan wawasan bagi PT. Merak Jaya Beton untuk meningkatkan efisiensi dan kinerja operasional Batching Plant KarangPilang dalam upaya menjaga kompetitivitasnya di pasar konstruksi.

Aggregate is the main component of road pavement structure, namely 90-95% of the weight of the pavement. Such a large proportion means that the quality of the aggregate used will greatly determine the overall performance of the pavement. The availability of quality aggregate is absolutely necessary to ensure the sustainability of development in the road construction sector. One area that has aggregate potential that has not been utilized optimally is Kandang Mbelang Village, Lawe Bulan. The aim of this research is to determine the characteristics of the Marshall, UCS, ITS test values ​​and the permeability of asphalt mixtures using the excavated material of Kandang Mbelang, Lawe Bulan as aggregate. This research uses experimental methods carried out in the laboratory with variations in asphalt content of 4.5%, 5%, 5.5% and 6% for the Marshall test and obtains Optimum Asphalt Content (KAO). For ITS, UCS and permeability testing, Optimum Asphalt Content was used with three samples each. Hypothesis testing for data comparison uses the T test method. The use of Kandang Mbelang aggregate in the AC-WC spec IV mixture produces a stability value of 711.5 kg, a flow value of 3.48 mm, a porosity value of 16.077%, a density value of 2.016 gr/ cm3 and Marshall Quotient value 215.823 kg/mm ​​at Optimum Asphalt Content of 5.3%. The average ITS value is 319.024 KPa, the average UCS value is 6,982.237 KPa, while the average permeability coefficient value is 7.14x10-4 cm/s. Through the T test statistical method, it is known that the use of the Kandang Mbelang aggregate for the AC-WC spec IV mixture does not cause changes in the stability, flow, ITS and UCS values. Real changes only occur for density values, porosity values ​​and permeability coefficients.

Quality control review of concrete at PT. Merak Jaya Beton is important to ensure that the work carried out meets quality standards and is implemented according to existing procedures. PT. Merak Jaya Beton is one of the companies in Indonesia that produces precast concrete. At PT. Merak Jaya Beton, quality is highly regarded from trials before being taken to projects (trial mix and F’c)to construction projects (Slump tests), checking the proportions of mixtures and uniformity of basic materials at the batching plant, to hammer test checks. The process of selecting the right concrete materials can determine the amount or quantity of dependency on materials considering the quality requirements of the concrete used. Several specifications of ready-mix concrete are produced to meet the specifications demands from clients. Meanwhile, for material quantity planning based on the production volume to be implemented, it includes material needs, ordering cycles, and the amount of orders. In concrete mixtures, there are materials added during the Mixing process (admixtures), this is aimed to alter the properties of concrete to make it more suitable and cost-effective.

Porous concrete has high porosity so that water can pass through the cavities in the concrete. The application of porous concrete is usually for parking areas, pedestrian sidewalks, road shoulders, drainage, roads with low traffic volume. Indonesia is an archipelagic country, most of Indonesia's territory is by the sea so it is very possible to use sea water as a substitute for fresh water for porous concrete. This research aims to determine the comparison of compressive strength of porous concrete mixed with sea water and normal porous concrete with variations in the water cement (fas) factor. In this study, a concrete mixture with a water cement (fas) factor of 0.30 and 0.35 was used. The test object used was a 15x30 cm cylindrical concrete test object for the compressive strength test. The test on porous concrete was carried out during the curing period of 28 days. The test results for the compressive strength of normal porous concrete with a water cement (fas) factor of 0.30 and 0.35 are 6.658 Mpa and 4.435 Mpa, then for porous concrete mixed with sea water with a water cement (fas) factor of 0.30 and 0, 35, namely 6,700 Mpa and 3,374 Mpa. The test results show that the sea water mixture in porous concrete does not affect the compressive strength of porous concrete, whereas the use of variations in the water cement factor (fas) shows that the compressive strength of porous concrete, both normal porous concrete and porous concrete mixed with sea water, has decreased. as the value of the water cement (fas) factor used increases.

This research aims to determine the effect of adding the additive Sika Fume on the compressive strength of concrete. This research uses a type of quantitative research with experimental methods, namely by carrying out several tests on test objects in the laboratory. The results of this research show that the compressive strength of concrete with the addition of sika fume varies 0%, 3%, 5%, 7% and 8% of the cement weight, so the experimental results show that the average compressive strength at the age of 28 days of concrete has a variation of 0 % of 26.14 Mpa, 3% variation of 25.01 Mpa, 5% variation of 27.08 Mpa, 7% variation of 24.16 Mpa, 8% variation of 23.40 Mpa. The concrete compressive strength variation of 5% with an average of 27.08 Mpa is the variation with the highest compressive strength value and reaches the design compressive strength. Meanwhile, a variation of 8% with an average of 23.40 Mpa is the lowest compressive strength value and does not reach the design compressive strength.

Road maintenance or upkeep is not an easy problem to do because it requires quite a large amount of money. This is what causes the government to appear slow in repairing road damage so that the damaged roads become worse and wider. In reality, so far the government has carried out road maintenance and repairs when the road was in a condition that was in serious disrepair, so it is certain that the costs required will be very large and it can also be ascertained that the losses suffered by road users while the road is damaged, are also very large. big or even worthless. However, in implementing the preservation program, proper management is required so that the preservation program can be carried out effectively and efficiently. The aim of this research is to determine the type of damage found on concrete roads in Maluku Village, Kec. Maritengngae District. Sidrap along 2 km and technical study of concrete road maintenance program in Maluku Village, District. Maritengngae District. Sidrap along 2 km. The results of the research show that the damage on the concrete road in Maluku Village, Kec. Maritengngae District. Sidrap has patch damage, edge damage, cracks, transverse cracks, longitudinal cracks and holes. The most dominant damage is damage to holes and damage to roads on the concrete road in Maluku Village, Kec. Maritengngae District. Sidrap has 2 types of treatment, including Periodic Maintenance and Routine Maintenance Program. And handling the most dominant type of damage from STA 0+000 to 2+000 is a routine maintenance program of 100%.

Concrete is an artificial stone made from a mixture of cement, sand, aggregate and water. For this reason, this construction material is considered very important to continue to be developed. One effort to develop is by improving the weak properties of the concrete itself. From this, researchers will use additional materials such as fiber palm fiber and sika visconcrate in the concrete mixture. Fiber fiber itself has durable properties and does not rot easily in open conditions or embedded in the ground, while sika visconcrate is a chemical that is used as an additive in the mixture to increase the workability, quality and strength of concrete with the desired properties. The method used in this research is quantitative experimentation. The aim of this research is to determine the characteristics of concrete using palm fiber and sika visconcrate with variations of 3%, 5% and 7% from normal concrete. The results of the research show that the average compressive strength of normal concrete is 25,572 MPa, 3% SI+SV variation concrete has an average of 27,365 MPa, 5% SI+SV variation concrete has an average of 26,704 MPa, and 7% SI+ SV variation concrete The average is 26,044 MPa. The split tensile strength test results of normal concrete averaged 6.074 MPa, 3% SI+SV variation concrete averaged 6.444 MPa, 5% SI+SV variation concrete averaged 7.852 MPa, and 7% variation concrete averaged amounting to 8,148 MPa.    

Concrete is a rock made from a mixture of cement, sand, aggregate and water. For this reason, this construction material is very important to develop. One effort to develop it is by utilizing industrial waste. Like other industrial waste, wood ash waste can also be used as a partial replacement for cement. The aim of this research is to determine the effect of adding wood ash as an additive to cement on the compressive strength and tensile strength of concrete, as well as to determine the effect of varying the percentage of wood ash in the concrete mixture on the compressive strength and split tensile strength of concrete. The type of research used in this research is quantitative research with experimental methods, namely by comparing normal concrete with 3 variations of mixture to determine the compressive strength and splitting tensile strength of the concrete. The results of the research showed that the experimental compressive strength and split tensile strength of concrete on normal concrete and variations of 3 mixtures, namely 2%, 4% and 6% of cement, obtained experimental results on the compressive strength of concrete for 28 days of normal concrete with an average of the average of 25,478 Mpa decreased with a 2% variation with an average of 24,723 Mpa, and decreased drastically for a 4% variation with an average of 19,439 Mpa, and for a 6% variation with an average of 18,967 MPa. Meanwhile, in testing the split tensile strength of normal concrete with an average of 7.185 Mpa, it experienced an increase from normal concrete with a variation of 2% with an average of 7.333 Mpa, and experienced a decrease from normal concrete with a variation of 4% with an average of 6.667 Mpa, and 6%. with an average of 6 Mpa. So it can be concluded that concrete with a variation of 2% wood ash does not really affect the compressive strength of the concrete, but the more wood ash that is added, the compressive strength of the concrete will decrease. From this research it can be concluded that the use of wood ash does not achieve the planned compressive strength so it is not suitable for use in construction.                                                                                                                                                         

One of the income taxes is Income Tax Article 23. In Income Tax Article 23 there is a process of withholding, depositing and reporting where if an error occurs in the process it can result in a shortfall in the amount of tax that should be deposited into the state treasury. Article 23 Income Tax Withholders are parties who pay income, namely government bodies, domestic corporate tax subjects, activity organizers, permanent establishments and other overseas representatives. This research was conducted at PT. Wijaya Karya Beton Tbk PPB. The aim of this research is to analyze the deduction, deposit and reporting of Income Tax Article 23 at PT. Wijaya Karya Beton Tbk PPB North Sumatra. The analytical method used is the descriptive method. Based on the research results, PT. Wijaya Karya Beton has implemented Article 23 Income Tax deductions and reporting in accordance with applicable tax regulations but PT. Wijaya Karya Beton TBK PPb North Sumatra in the implementation of income tax payment article 23 there are still things that are not on time, namely exceeding the deposit limit specified in Law Number 36 of 2008 concerning income tax article 23. In this research it can be concluded that PT. Wijaya Karya Beton has carried out its obligations properly in carrying out deductions and reporting Income Tax Article 23 and it is best that in carrying out the payment of income tax article 23 not exceed the deposit limit specified in Law Number 36 of 2008 concerning income tax article 23.