Construction and Material Journal
EISSN : 2655-9625
Published by: Politeknik Negeri Jakarta (10.32722)
Total articles ≅ 60
Latest articles in this journal
Construction and Material Journal, Volume 3, pp 25-31; https://doi.org/10.32722/cmj.v3i1.3729
In selecting the formwork work method, the things that need to be considered include cost, quality, and time. Comparison of several methods of formwork work is carried out to obtain the correct method. Comparisons were made to the Semi System formwork method and the Aluminum formwork method. To compare the two methods requires volume calculation, the multiplier coefficient referred to by the PUPR Regulation No. 28 / PRT / M / 2016, non-conformence data, and work duration. This data is processed into the need for the cost of formwork for the two methods based on the PUPR Ministerial Regulation Number 28 / PRT / 2016, the percentage of concrete defects due to formwork, and the scheduling duration presented in the bar chart. The two methods are compared based on the need for the cost of the work, the number of percent of quality, and the work duration. The comparison shows that the aluminum formwork method is superior in terms of cost (RAB). It is produced more efficiently by 3.4%. In terms of quality, this method results in less damage (concrete defects) to minimize repair costs later, and when the work reaches 43% more effective.
Construction and Material Journal, Volume 3, pp 65-72; https://doi.org/10.32722/cmj.v3i1.3731
Concrete is a material commonly used for structural work. However, concrete has one disadvantage, namely that its specific gravity is high enough so that the dead load on a structure becomes large. One way to deal with high concrete density is to use Styrofoam waste as a substitute for some of the fine aggregate. This research was conducted to examine the physical and mechanical properties as well as the optimum value of compressive strength, split tensile strength and modulus of elasticity of concrete with a 0.4 fas using Styrofoam as a partial substitute for fine aggregate. The research method used is an experimental method by making the test object in the form of a concrete cylinder with a diameter of 15 cm and a height of 30 cm. The composition of the concrete mixture used is a volume ratio of 1 Pc: 2 Ps: 2 Kr with a fas 0.4. The styrofoam variations used are 10%, 20%, and 30% of the ratio to the volume of fine aggregate in normal concrete mixtures. Testing of the mechanical properties of concrete was carried out at the age of 7, 14, 21, and 28 days for the concrete compressive strength test, and 28 days for the split tensile strength of the concrete, and the modulus of elasticity. The results showed that the compressive strength of the concrete increased with the age of the concrete and the addition of the styrofoam variations with the exception of the 10% variation. For the split tensile strength test, there was an increase in line with the increase in the styrofoam variation, while the modulus of elasticity decreased at 10% variation against 0% variation and increased at 20% and 30% variation with 0% variation.
Construction and Material Journal, Volume 3, pp 15-24; https://doi.org/10.32722/cmj.v3i1.3506
Perkembangan dunia konstruksi yang sudah sangat pesat di Indonesia terbukti dengan adanya metode baru untuk konstruksi yaitu Building Information Modelling (BIM). Munculnya BIM ini diklaim dapat membuat pekerjaan menjadi efektif dan efisien. Sebelum adanya BIM, kegiatan engineering dilakukan dengan menggunakan metode konvensional atau yang telah dikenal dengan AutoCAD, SAP, Ms. Project yang sering digunakan untuk pekerjaan perencanaan proyek. Pekerjaan menggunakan aplikasi tersebut memakan lebih banyak waktu karena dari masing-masing aplikasi tersebut harus dikerjakan secara manual. Hal ini berbeda dengan BIM yang antar aplikasinya dapat terintegerasi satu sama lain, sehingga dapat mempercepat proses pekerjaan yang akan menyingkat waktu dan juga membuat sumber daya manusia menjadi lebih sedikit. Dalam penelitian ini akan dijelaskan apa saja perbedaan jelas proses perencaan konstruksi khususnya saat pembuatan metode kerja dan shopdrawing yang ditinjau dari segi biaya, mutu, waktu. Dan juga akan mengetahui apa saja kelebihan dan kekurangan BIM karena ini adalah sesuatu yang baru, maka dari tiu untuk penelitian ini dilakukan dengan metode kueisioner dan wawancara kepada para draftrer dan engineer yang sudah berkecimpung didunia konstruksi dan sudah merasakan menggunakan BIM. Dengan studi kasus perencanaan Jalan Tol Jakarta – Cikampek II Selatan (Paket 3) dilakukan perbandingan efiseiensi biaya dan waktu dengan metode konvensional dan BIM. Penelitian ini menghasilkan kesimpulan bahwa aplikasi BIM dapat mempercepat proses pelaksanaan kerja sebesar 43.82%, tetapi berbeda dengan biaya lebih mahal dari konvensional dikarenakan biaya investasi awal untuk lisensi software yang mahal.
Construction and Material Journal, Volume 3, pp 41-49; https://doi.org/10.32722/cmj.v3i1.3735
Environmental damage and global warming has become an issue in the world. Developments in the construction project has a large influence in environmental change on the surface of the earth. Construction activities start from the constructing stage to the operating stage. Green construction is one part of the sustainable development that is required to participate in environmental sustainability. With this background, the author agreed to explain the criteria, stages of difficulty and obstacles in implementing Green Construction. Data collected by questionnaire method and data analysis using SPSS Statistics 26. The results of this study obtained the value of the Green Construction criteria that applied is waste project variables with an average value of 3,748 and the lowest is site project variables with average 3,198. The most dominant factor of difficulty in applying Green Construction is the water usage variable with an average value of 3,283 and the lowest difficulty in applying is the energy variable with an average of 2,817. The most challenging obstacle factor in implementing Green Construction is the cost factor with an average value of 4.00 and the lowest obstacle is the efficient design variable with an average of 2.96. Thus, from the results of this study is expected that the contractor can help more actively in improving the implementation of Green Construction in this construction project.
Construction and Material Journal, Volume 3, pp 33-40; https://doi.org/10.32722/cmj.v3i1.3744
Concrete is the most important part of a construction building. The purpose of this study was to examine how the comparison of physical and mechanical properties and optimum levels of the addition of straight tie wire as an added material with a water-cement ratio of 0.4. The percentage of addition of straight tie wire: 0%, 0.5%, 0.75%, 1.0%, of the total weight of the specimen with a tie-wire length of 8 cm. The test specimens for compressive strength, modulus of elasticity, and split tensile are in the form of a cylinder with a diameter of 15 cm and a height of 30 cm, and the specimen for flexural strength is a block with a length of 50 cm, a width of 10 cm and a height of 10 cm. The results show that the maximum compressive strength test on tie wire occurred at a percentage of 0.75% of 16.56 MPa. The maximum modulus of elasticity in tie wire occurred at a percentage of 0.75% of 15184.56 MPa. The maximum split tensile strength of tie wire occurred in a percentage of 0.75% of 1.165 MPa, and the maximum flexural strength of tie wire occurs at a percentage of 0.75% of 1.950 MPa. The research results concluded that the addition of a straight tie-wire to the concrete mixture could increase the compressive strength, split tensile strength, tensile strength, and elastic modulus of concrete.
Construction and Material Journal, Volume 3, pp 51-56; https://doi.org/10.32722/cmj.v3i1.3748
The purpose of this research is to recalculate the upper structure of the X building of Jakarta State Polytechnic uses SNI-2847-2019 regulations regarding concrete and SNI 1726- 2019regarding earthquakes. This building consists of 3 floors which use concrete as its main structure. Recalculation includes structural elements starting from collar beam, floor plates, beams, and columns, which are expected to withstand the loads who worked on it. Structural analysis was performed using the ETABS 2013 software. Especially for the calculation of the column structure, the SP Column software is used. The results were obtained from the recalculation of the PNJ x Building in the form of dimensional differences and reinforcement against the existing building. Dimension and reinforcement after redesign became more the size of the existing building. The recalculation results indicate that planning re-using SNI 1726-2019 and SNI 2847-2019 are strong to bear the working load after the dimensions and reinforcement are enlarged.
Construction and Material Journal, Volume 3, pp 57-63; https://doi.org/10.32722/cmj.v3i1.3738
One method aimed to know the condition of the pavement runway on an airport is pavement condition index (PCI). This method has three parameters, type damage, severity damage, and the number of damage or density. In this research, the assessment of PCI is done on a runway (flexible pavement) at one of the airports in Jakarta with a broad 3000 m x 45 m. PCI’s value is gained by following a method from ASTM D 5340-98 (Standard Test Method for The Airport Pavement Condition Index Surveys) from all total sample. The research obtained shows that runway airports have an average of 75,59 (very good). Consisting of excellent as many as 138 sample (38 %), very good as many as 102 sample (28 %), good 60 sample (17 %), fair 36 sample (10 %), poor 16 sample (5 %), very poor as many as 7 sample (2 %), and failed 1 sample (0.001 %). All repairs to the damaged area which are lower than excellent condition using patching with a cold milling machine.
Construction and Material Journal, Volume 3, pp 1-14; https://doi.org/10.32722/cmj.v3i1.3686
Expansive soil has a high swelling and shrinkage ability which can damage the buildings above it. Glagahagung Village, Purwoharjo District, Banyuwangi Regency is one of the areas suspected of having this type of soil. Residents often experience problems in their residential buildings every year, such as cracks in floors, walls, columns, and beams. Several methods can be used to improve expansive soil, including physical and mechanical stabilization. In this study, lime and cement were used as physical stabilizers. On the other hand, sand is used as a mechanical stabilizer. Physical and mechanical parameters will be observed in the stabilization process. Based on the three stabilizers, a 5% cement mixture can be the best alternative. Cement stabilizers can increase the maximum dry volume weight, reduce the rate of soil swelling, and change natural soils' classification from high plasticity clay to silty sand.
Construction and Material Journal, Volume 2, pp 213-218; https://doi.org/10.32722/cmj.v2i3.3530
Surabaya–Gempol Toll Road is a toll that has operated since 1986, but in 2006 the Porong-Gempol route collapsed due to lapindo mud flow. Therefore, the toll road needs a relocation. On the construction of its relocation, additional scope of work was added and affected the feasibility of the investment which must be put into consideration for analyzing purposes in order to regain the initial feasibility value of 14.84% IRR. The forecast of cost and income analyzed with financial approach. The method used are Net Present Value (NPV) and Internal Rate of Return (IRR) with a discount rate of 11.8%. The result of investment feasibility after additional scope of work shows that the NPV during concession period (39 years) is negative Rp459.150.000.000,00 and IRR at NPV = 0 is 9,55%. To return the feasibility value, concession period is must be increase to 50 years with adjustment of the toll fee to Rp1.625 in 2021 and Rp1.980 in 2023. It shows that NPV is Rp1.037.727.000.000,00 and IRR at NPV = 0 return to 14,84%.Keywords: Additional scope of work; Compensation; Feasibility; RelocationABSTRAKJalan Tol Surabaya-Gempol merupakan jalan tol yang sudah beroperasi sejak tahun 1986 akan tetapi pada tahun 2006 ruas tol Porong-Gempol terputus oleh lumpur lapindo sehingga perlu dilakukan relokasi. Dalam pembangunan relokasi ruas tol tersebut, terjadi tambahan lingkup pekerjaan sehingga membuat biaya investasi membengkak sehingga perlu diketahui pengaruhnya terhadap nilai kelayakan investasi proyek tersebut untuk kemudian dilakukan analisis dalam upaya pengembalian nilai kelayakan yaitu IRR sebesar 14,84% seperti kondisi awal. Prakiraan biaya dan pendapatan akan dianalisis dengan pendekatan finansial. Metode yang digunakan adalah Net Present Value (NPV) dan Internal Rate of Return (IRR) dengan discount rate 11,8%. Hasil evaluasi kelayakan investasi akibat tambahan lingkup pekerjaan menunjukkan bahwa NPV selama masa konsesi (39 tahun) adalah negatif Rp459.150.000.000,00 dan IRR pada NPV = 0 adalah 9,55%, nilai IRR ini lebih kecil dari discount rate yaitu 11,8%. Untuk mengembalikan nilai kelayakan, dilakukan skema kompensasi penambahan masa konsesi menjadi 50 tahun dan penyesuaian tarif tol baru menjadi Rp1.625,00 pada tahun 2021 dan Rp1.980,00 pada tahun 2023. Hasil dari skema kompensasi tersebut menunjukkan bahwa NPV sebesar Rp1.037.727.000.000,00 dan IRR pada NPV = 0 kembali ke nilai 14,84%.Kata kunci: Kelayakan; Kompensasi; Relokasi; Tambah Lingkup
Construction and Material Journal, Volume 2, pp 183-193; https://doi.org/10.32722/cmj.v2i3.3471
Steel beams are susceptible to initial geometric imperfections due to improper fabrication and installation processes. Consequently, long steel beams without stiffening are prone to bending due to lateral torsion. The purpose of this study is to determine the effect of variations in the initial geometric imperfections of Single Curvature-Moment (SCM) on the moment, total displacement, displacement in the X direction (U1), displacement in the Y direction (U2), and twist. This study used an RH profile with a compact wing and body. The boundary condition used is a simple beam with an initial geometric imperfection due to single moment-curvature (SCM) bending. The variations used are the initial geometric imperfections values of SCM 0 mm (without initial geometric imperfections), SR5 (with initial geometric imperfections of 5 mm), and SR10 (with initial geometric imperfections of 10 mm). Initial geometric imperfections of SCM in steel beam decreased moment capacities up to more than 2% in elastic conditions and 12% in plastic states. This SR10 beam is also a beam that has a displacement of the X-axis (U1 = -203,960 mm), a displacement of the Y-axis (U2 = -255,615 mm), and the most significant twist (28,179 °).Keywords: buckle, initial geometric imperfections, Single Curvature-MomentABSTRAKBalok baja rentan mengalami initial geometric imperfections akibat proses pabrikasi maupun pemasangan yang kurang tepat. Sementara balok baja yang panjang tanpa pengaku rentan mengalami tekuk akibat torsi lateral. Tujuan dari penelitian ini adalah untuk menentukan dampak variasi besarnya initial geometric imperfections Single Curvature-Moment (SCM) terhadap momen, displacement total, displacement arah X (U1), displacement arah Y (U2), dan twist. Penelitian ini menggunakan profil RH dengan sayap dan badan yang kompak. Boundary condition yang digunakan adalah balok sederhana dengan initial geometric imperfections akibat tekuk single momen curvature (SCM). Variasi yang digunakan adalah besarnya nilai initial geometric imperfections SCM 0 mm (tanpa initial geometric imperfections), SR5 (dengan initial geometric imperfections 5 mm), dan SR10 (dengan initial geometric imperfections 10 mm). Dari hasil penelitian diketahui bahwa pada kondisi elastis, leleh, maupun plastis, balok dengan initial geometric imperfections SCM menunjukkan penurunan kapasistas momen mengalami penurunan hingga mencapai lebih dari 2% pada kondisi elastis dan 12% pada kondisi plastis. Balok SR10 juga merupakan balok yang memiliki displacement arah sumbu X (U1=-203,960 mm), displacement arah sumbuY(U2=-255,615 mm), dan twist yang paling paling besar (28,179°).Kata kunci: tekuk, initial geometric imperfections, Single Curvature Moment