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Penggunaan fly ash sebagai bahan tambahan untuk menggantikan sebagian semen merupakan salah satu hal untuk mendorong penggunaan material alternatif. Penelitian ini mengkaji pengaruh persentase substitusi fly ash sebesar 10%, 30%, dan 50% dengan penambahan zat aditif superplasticizer sikament-NN (Tipe F) dengan dosis 1,2% terhadap kemudahan pengerjaan (workability) dan kekuatan tekan beton. Kinerja beton dianalisis berdasarkan kekuatan tekannya pada hari ke-28 dab kelancaran kerjanya berdasarkan slump. Hasil penelitian ini menunjukan bahwa kombinasi penggunaan fly ash dan superplasticizer sikament-NN (Tipe F) dapat meningkatkan kemudahan adukan, dengan nilai slump maksimum mencapai 14,3 cm pada presentase fly ash 50%. Namun, peningkatan kelacakan ini berbanding terbalik dengan kekuatan tekan yang konsisten menurun seiring dengan peningkatan penambahan fly ash. Nilai kuat tekan maksimum dicapai oleh campuran beton yang hanya menggunakan superplasticizer tanpa fly ash sebesar 320,50 kg/cm2, sementara nilai yang optimal ditemukan pada variasi persentase 10% dengan penambahan superplasticizer 1,2% menghasilkan kuat tekan sebesar 307,65 kg/cm2, sehingga penggunaan kombinasi ini diharapkan dapat memberikan kontribusi efisiensi bagi rekayasa sipil.

Concrete volume calculation is a crucial factor in preventing cost overruns when preparing the Budget Plan (RAB) for construction projects. In arch bridge projects, the complex structural geometry often makes conventional volume calculation methods complicated and prone to errors, particularly due to the geometric complexity of the arch beams. This study aims to analyze the comparison of concrete volume calculation results between the conventional method and the Building Information Modeling (BIM) method using Autodesk Revit in terms of cost-effectiveness. The case study was conducted on the Short Span II Pulau Balang Bridge Duplication Project in the Nusantara Capital City (IKN), Penajam Paser Utara Regency, East Kalimantan. The research objects include substructures (bore piles, pile caps, abutments, piers, and wing walls) and superstructures in the form of arch beams. The research method employs a quantitative approach by calculating concrete volumes conventionally using AutoCAD and Microsoft Excel, as well as calculating with BIM Autodesk Revit through three-dimensional modeling and Quantity Take-Off (QTO) exports. The results indicate that the BIM Autodesk Revit method generates a larger concrete volume compared to the conventional method, resulting in a higher total cost based on the BIM volume. The total cost for the conventional method amounted to IDR 142,613,245,996.12, while the BIM Autodesk Revit method amounted to IDR 143,127,208,186.60. These differences are influenced by the level of calculation detail, the simplification of shapes in the conventional method, and the precision of modeling in Autodesk Revit.

Modern infrastructure development often involves the use of mass concrete in large structural elements such as pile caps and foundations. However, massive concrete volumes trigger a significant temperature increase due to the heat of hydration that is difficult to dissipate, posing a risk of thermal stress and structural cracking. This study aims to analyze the temperature rise behavior of mass concrete and evaluate the effectiveness of combining chilled water and fly ash substitution in minimizing these thermal cracking risks.The research method employs a quantitative approach through laboratory testing at PT Adhimix RMC Plant Kaligawe. Specimen blocks measuring 40 x 40 x 100 cm were divided into three variations: normal concrete (BN), concrete with chilled water and 15% fly ash (BAF), and concrete with 25% fly ash (BF). Temperature was monitored using thermocouples at the core and surface for 14 days, then validated using the Portland Cement Association (PCA) formula. The results indicate that the integration of chilled water with 15% fly ash and the use of 25% fly ash significantly controlled extreme temperature surges at the 5th hour. The combination of chilled water and 15% fly ash produced the lowest core temperature of 37.3°C, far below the control concrete which reached 62.4°C. This proves that the combination of precooling methods and fly ash substitution is effective in reducing the heat of hydration during the early hardening period, although the use of 25% fly ash was found to be more stable in maintaining mass concrete temperature.

Self-Compacting Concrete (SCC) requires a high cement content, which contributes to increased carbon emissions; therefore, this study evaluates the effect of partial cement substitution with fly ash (5%, 10%, and 15%) and the addition of Polyethylene Terephthalate (PET) waste (0.5% and 0.7%) on the mechanical properties of SCC with a target strength of f’c 30 MPa. The research employed laboratory experimental methods, including fresh concrete tests (slump flow, L-box, and V-funnel) and hardened concrete tests (compressive, tensile, and flexural strength) at 7 and 28 days. The results indicate that fly ash substitution enhances compressive strength, with the highest value of 49.59 MPa achieved at 5% fly ash at 28 days, exceeding normal concrete (34.73 MPa). The addition of PET tends to reduce compressive strength due to increased porosity; however, it significantly improves flexural strength, as the combination of 5% fly ash and 0.5% PET achieved 4.7 MPa compared to 2.9 MPa for normal concrete. Overall, the combination of fly ash and PET waste shows potential for application in structural elements requiring high flexural performance.

Heavy equipment effectively plays a key role in ensuring productivity and efficiency in the precast concrete industry of spun pile concrete at PT Adhi Beton Purwakarta. One of the heavy equipment that plays an important role is the mobile crane, especially for moving large concrete components. In this study, field data was processed by analyzing the productivity and efficiency of the Tadano GR-500EXL type mobile crane with a capacity of 50 tons. Current problems are high idle time, lack of operational synchronization, and suboptimal utilization of technological features on the crane unit. The results show that spun pile concrete weighing 6.78 tons based on the analysis of heavy equipment productivity is 40.68 tons/hour with the number of mobile crane heavy equipment needed as many as 2 units, and the efficiency for crane heavy equipment reaches around 68%. The amount of productivity and needs are to support the target of achieving precast concrete production, especially spun pile concrete. Thus, it is expected that the amount of productivity and the number of mobile crane heavy equipment needs are optimal to support production.

The development of science and technology generally brings positive impacts in terms of convenience in various human activities, but on the other hand, it also leads to negative consequences such as an increase in waste. One of the significant wastes produced from construction activities, including building and house construction, is feldspar, which typically comes from leftover ceramic materials. Feldspar is a type of waste that is difficult to decompose naturally and has no economic value, often accumulating and polluting the environment. Therefore, innovation is needed to utilize this waste to create value. This study aims to use feldspar powder as a replacement for fine aggregates in K-200 grade concrete mixtures. The research method involved mixing feldspar powder in specific proportions as a substitute for sand, followed by a series of tests, including compressive strength and flexural tests, to determine the feasibility and performance of the resulting concrete. The results indicate that the use of feldspar powder as a fine aggregate produces a concrete mixture with satisfactory mechanical characteristics, meeting the K-200 concrete standards. These findings not only provide an alternative environmentally friendly material but also offer a solution to reduce ceramic waste, contributing positively to sustainable construction.

This study analyzes a 10-floor multi-story lecture building in Lombok, focusing on the impact of concrete quality degradation on the building's performance. Due to limited material access, the actual on-site concrete quality changed from the design quality of fc 30 MPa to fc 24.9 MPa. The building structure was modeled in 3D using ETABS v22 software, and two structural models were compared: one with the design concrete quality (fc' 30 MPa) and one with the actual quality (fc' 24.9 MPa). The analysis evaluated dynamic performance, inelastic displacements, P-Delta effects, and reinforcement requirements. The comparison aimed to assess the impact of concrete degradation on structural stiffness, inter-story displacements, and reinforcement needs. The results show that concrete quality deterioration increases the structure's vibration period, inelastic displacement, and lateral forces due to P-Delta effects. While beam reinforcement requirements remain mostly unchanged, column reinforcement significantly increases, especially in columns with large axial forces. This study provides valuable insights into the technical consequences of concrete quality degradation and serves as a reference for evaluating structural redesigns in projects facing material limitations.

This study examines the application of double integrals in calculating the volume of cylindrical concrete piles as a basis for estimating material requirements in building foundation structures. The volume calculation was carried out using a double-integral approach in polar coordinates for three pile segments with lengths of 4 m, 3.9 m, and 4 m, each having a diameter of 60 cm. The results were then validated using the standard geometric formula to ensure consistency and mathematical reliability. The obtained concrete volume was subsequently used to estimate material needs based on a 1:1.5:3 mix proportion consisting of cement, sand, and gravel. The findings indicate that double integrals can be effectively applied to generate accurate estimations of both volume and material requirements, supporting logistical planning in construction. This approach also highlights the strong connection between mathematical concepts—particularly multivariable calculus—and practical applications in civil engineering. Furthermore, the study emphasizes that double integrals may serve as a relevant alternative when structural modeling requires deeper analytical exploration or validation beyond conventional geometry. Therefore, the implementation of double integrals not only reinforces theoretical understanding but also enhances precision in evaluating structural components within building foundation planning.

Penelitian ini menganalisis perilaku lentur balok beton bertulang dengan tulangan Glass Fiber Reinforced Polymer (GFRP) dibandingkan tulangan baja konvensional, ditinjau dari beban maksimum, lendutan maksimum, dan pola keruntuhan. Pengujian eksperimental dilakukan pada balok beton mutu K-225 berdimensi 150 × 150 × 600 mm menggunakan metode pembebanan dua titik. Benda uji terdiri atas balok kontrol (BKA dan BKB) serta balok variasi (BVA dan BVB). Hasil pengujian menunjukkan bahwa balok bertulangan GFRP memiliki kapasitas beban maksimum yang lebih tinggi, dengan peningkatan dari 28,68 kN menjadi 58,40 kN (103,6%) pada BKA–BVA dan dari 55,71 kN menjadi 68,01 kN (22,1%) pada BKB–BVB. Namun, balok variasi mengalami lendutan maksimum yang lebih besar, yaitu 7,74 mm dan 5,38 mm, dibandingkan balok kontrol sebesar 2,22 mm dan 2,92 mm. Pola keruntuhan menunjukkan bahwa balok kontrol mengalami keruntuhan lentur yang bersifat daktail, sedangkan balok variasi cenderung mengalami keruntuhan rapuh dengan dominasi retak lentur dan geser. Hasil ini menunjukkan bahwa tulangan GFRP efektif meningkatkan kapasitas beban balok, namun disertai dengan lendutan yang lebih besar dan keruntuhan yang lebih cenderung getas.

Beton sebagai material utama konstruksi sering mengalami panas hidrasi yang menyebabkan perbedaan suhu permukaan dengan suhu inti, akan berpotensi retak dini dan penurunan kuat tekan. Penelitian ini menganalisis potensi air es dan fly ash 10% substitusi semen untuk memperkecil suhu beton mutu 35 MPa dengan aditif tipe D (retarder) dan F (superplasticizer), serta pengaruhnya terhadap kuat tekan. Metode deskriptif menggunakan data sekunder mix design tiga variasi: non fly ash, fly ash 10% dan fly ash 10%+air es 10°C. Suhu beton segar diukur dengan thermogun/thermometer lalu kuat tekan uji silinder diameter 150x300 mm umur 7 hari dan 28 hari dengan total 18 benda uji. Hasil menunjukkan suhu beton segar non fly ash berada pada rentang normal, beton fly ash 10% turun 1-2°C (reaksi pozzolanik lambat yang mengurangi panas hidrasi dari C2S, C3S, dan C3A), beton fly ash 10% + air es turun 5-6°C. Kuat tekan 7 hari menunjukkan beton non fly ash 33,69 MPa, beton fly ash 10% 34,14 MPa, beton fly ash 10%+air es 34,73 MPa. Pada umur 28 hari menunjukkan beton non fly ash 39,73 MPa, beton fly ash 10% 39,80 MPa, dan beton fly ash 10%+air es 39,65 MPa – semua melebihi mutu rencana.

Pengukuran deformasi yang akurat pada struktur beton dibawah pembebanan sangat penting untuk mengevaluasi kinerja dan daya tahan elemen-elemen tersebut. Ada beberapa keterbatasan dalam mengevaluasi struktur beton secara konversional seperti memerlukan waktu dan biaya besar. Beberapa penelitian menunjukan potensi fotogrametri jarak dekat dan pemodelan tiga dimensi (3D) mampu menganalisa deformasi, tegangan/regangan internal, dan perambatan retak. Penelitian ini mengusulkan metode pengukuran deformasi dengan empat tahapan untuk mengembangkan model 3D beton dengan menggunakan teknik fotogrametri jarak dekat dan selanjutnya pengolahan gambar. Tahapan metode yang digunakan: 1) mempersiapkan perangkat uji dan persiapan beton, 2) akuisisi gambar beton menggunakan kamera sebelum pengujian kuat tekan, menguji kuat tekan beton dibawah pembebanan, kemudian akuisisi gambar setelah pengujian kuat tekan beton, 3) melakukan pengolahan untuk menghasilkan model 3D beton, dan 4) membandingkan hasil model 3D sebelum dan sesudah pengujian kuat tekan beton. Untuk deformasi terkecil berapa pada sample beton 2 dengan loss volume sebesar 4%. Sementara itu, untuk deformasi terkecil berapa pada sample beton 3 dengan loss volume sebesar 26% yang menunjukan kuat tekan beton optimum berapa pada sample beton 2.

The use of sengon albasia ash waste as a partial cement substitute in concrete production is carried out to reduce combustion waste and also reduce cement use. This study focuses on the use of sengon albasia wood ash waste. The use of sengon albasia wood ash as a cement substitute causes a significant decrease in the slump test value. The use of sengon albasia wood ash as a partial cement substitute in concrete mixes actually produces different results depending on the proportion. If added as much as 10%, the concrete's compressive strength actually increases, but if it reaches 20% or 30%, the compressive strength actually decreases. This occurs because this type of wood ash has a significant water absorption capacity. As a result, the water that should be used for The chemical activity occurring between cement and water is diminished, so that the bond between the cement mixture as a binder and aggregate as a filler is reduced, and ultimately the concrete's compressive strength also decreases.

Beton merupakan material utama konstruksi yang masih memiliki kelemahan pada kuat tekan dan permeabilitas. Inovasi dengan penambahan Superplasticizer diharapkan mampu meningkatkan kualitas beton. Permasalahan penelitian ini adalah bagaimana pengaruh variasi dosis Superplasticizer (1%, 1,5%, dan 2% dari berat semen) terhadap kuat tekan dan permeabilitas beton dibandingkan beton normal. Penelitian ini menggunakan metode eksperimen dengan membuat 48 sampel beton silinder dan kubus yang diuji kuat tekan pada umur 7, 14, dan 28 hari serta permeabilitas pada umur 28 hari. Hasil penelitian menunjukkan bahwa penambahan Superplasticizer mampu meningkatkan kuat tekan dan menurunkan permeabilitas, sehingga dapat menghasilkan beton yang lebih kuat, kedap air, dan tahan lama.

Bangunan yang berada di daerah rawan gempa dengan tanah lunak cenderung memiliki tingkat kerentanan yang lebih tinggi. Dalam merancang struktur bangunan bertingkat, beban gempa menjadi salah satu parameter utama yang sangat berpengaruh. Kekuatan sebuah bangunan ditentukan oleh elemen-elemen struktur yang menopangnya dan kolom merupakan elemen struktur yang memiliki peran penting dalam konstruksi. Jika kolom mengalami kegagalan, bangunan yang ditopangnya berpotensi runtuh. Oleh karena itu, rendahnya ketahanan konstruksi di wilayah ini tetap menjadi permasalahan yang sedang diteliti saat ini. Tujuan penelitian ini untuk mengetahui seberapa jauh pengaruh variasi dimensi kolom terhadap struktur bangunan terhadap gempa, sehingga diperoleh ukuran dimensi kolom yang paling optimal. Pada penelitian ini, objek yang digunakan adalah bangunan 8 lantai yang terdiri dari lantai 1-3 merupakan kantor dan lantai 4-8 merupakan hunian. Pada perencanaan ulang bangunan ini berpedoman pada persyaratan beton struktural (SNI 2847:2019), perencanaan ketahanan gempa (SNI 1726:2019), dan beban minimum untuk perancangan bangunan gedung dan struktur lain (SNI 1727:2020), dengan pemodelan menggunakan software ETABS V.22. Redesain bangunan ini untuk mengetahui ukuran dimensi kolom yang paling optimal. Hasil penelitian perubahan dimensi kolom terhadap kekuatan struktur bangunan yakni dengan memperbesar dimensi kolom, kapasitas penampang bertambah yang dapat meningkatkan ketahanan kolom terhadap beban gempa. Selain itu, dimensi yang lebih besar juga membantu mengurangi tegangan aksial pada kolom, sehingga menurunkan risiko kegagalan akibat tegangan berlebih atau kelelahan material. Semakin besar dimensi kolom yang digunakan maka semakin kecil nilai simpangan yang dihasilkan. Artinya dengan dimensi kolom yang lebih kecil memiliki resiko yang lebih tinggi, sebab nilai simpangan lebih dekat dengan batas yang diijinkan. Akan tetapi hasil analisis menunjukkan bahwa dimensi kolom dengan berbagai variasi masih aman dari pengaruh delta izin.

Penelitian ini bertujuan untuk mengetahui berat beton, kuat tekan dan nilai biaya pada beton campuran styrofoam sebagai pengganti agregat kasar untuk mendapatkan beton ringan dengan cara membuat benda uji berbentuk silinder Ø15-30 cm dengan perbandingan volume 1 Pc: 2 Pasir: 3 Styrofoam, 1 Pc : 1.5 Pasir: 2, 5 Styrofoam dan 1 Pc : 1,25 Pasir : 2,75 Styrofoam serta beton normal dengan komposisi 1 Pc : 2 Pasir dan 3 Agregat kasar sebagai pembanding. Berat volume yang diperoleh untuk komposisi 1 Pc: 2 Pasir: 3 Styrofoam adalah 1323,64 kg/m3,komposisi 1 Pc: 1,5 Pasir: 2,5 Styrofoam adalah 1274,61 kg/m3,dan komposisi 1 Pc : 1,25 Pasir : 2,75 Styrofoam adalah 1112,46 kg/m3, dan beton normal 1 Pc : 2 Pasir : 3 Kerikil adalah 2366,33 kg/m3. Selisih berat beton styrofoam terhadap beton normal kurang lebih 47,73%. Kuat tekan karakteristik komposisi 1 Pc: 1,5 Pasir: 2,5 Styrofoam 85,73 kg/cm2, 1 Pc: 1,25 Pasir: 2,75 Styrofoam 80,39 kg/cm2 sedangkan kuat tekan karakteristik untuk komposisi 1 Pc: 2 Pasir: 3 Styrofoam adalah 110,31 kg/cm2 (>100 kg/cm2) dan beton normal 1 Pc : 2 Pasir : 3 Kerikil adalah 155,29 kg/cm2. Berat volume beton  campuran styrofoam dan karakteristik kuat tekan menunjukkan bahwa styrofoam sebagai pengganti agregat kasar hanya ditujukan untuk pekerjaan konstruksi ringan. Biaya pembuatan beton komposisi 1 Pc: 2 Pasir: 3 Styrofoam adalah Rp. 1.751.365, 1 Pc: 1,5 Pasir: 2,5 Styrofoam sebesar Rp. 1.555.587, dan komposisi 1 Pc : 1,25 Pasir : 2,75 Styrofoam sebesar Rp. 1,604,697, sedangkan untuk beton normal 1 Pc : 2 Pasir : 3 Kerikil hanya sebesar Rp. 631,293. Selisih perbandingan biaya beton campuran styrofoam lebih mahal kisaran 63,95% dari harga beton normal.

This study analyzes the influence of price, time efficiency, and product quality on ready-mix concrete sales volume at PT Dirgantara Betonindo Batang. This study employed a quantitative method with a causal approach, gathering data through surveys, interviews, and document analysis. A total of 70 respondents were selected using purposive sampling. The outcomes of the multiple linear regression analysis demonstrate that both time efficiency and product quality significantly influence sales volume, while price has a positive but insignificant effect. The regression model can explain 72.2% of the variation in sales volume. These findings provide strategic recommendations for company management in improving efficiency and quality to drive sales

Consistent and efficient concrete quality in each implementation is one of the main factors in the success of construction projects. Concrete as a structural material requires strict quality control in order to meet the technical standards that have been set. One way to improve the quality of concrete is to add certain additives to the job mix formula (JMF). This research is focused on the application of SG type additives known as chemical-based additives to improve the properties of fresh concrete and hard concrete. SG additives have an important function in increasing workability, speeding up or slowing down the binding time as needed, maintaining quality stability, and strengthening concrete finishes. In this study, a comparison was made between a concrete mixture with SG additives and a concrete mixture without additives. The tests included slump parameters, initial binding time, and compressive strength at 7 and 28 days of age. The test results showed a significant difference, especially in the improvement of the consistency and compressive strength of concrete with the use of additives. The results of the discussion showed a comparison of Trial Mix 1 and Trial Mix 2 that are different in terms of material composition, cost efficiency, and compressive strength of concrete. Trial Mix 2 with the composition of cement, admixture, water, and aggregate (sand and split) showed more optimal results. The compressive strength achieved was 821,396.00 kg/cm² at the age of 28 days. In terms of cost, Trial Mix 2 requires Rp. 351,582.00 per m³, with an efficiency difference of around Rp. 32,953.00 per m³ compared to the previous mix

This study aims to analyze the growth of tilapia (Oreochromis niloticus) cultivated in a concrete pond system in Dusun IV, Fadoro Lasara Village, Gunungsitoli City. The concrete pond system was chosen for its advantages in land efficiency, ease of management, and ability to maintain stable water quality. The research method employed a quantitative experimental approach over 60 days, with 200 Nile tilapia as the study subjects. The parameters observed included absolute weight and length gain, specific growth rate (SGR), feed conversion ratio (FCR), and survival rate (SR). The results showed that the average weight of the fish increased from 5.12 grams to 98.46 grams, with a length increase of 12.5 cm. The SGR was recorded at 4.29% per day, FCR at 1.38, and SR at 96.5%. These results indicate that the concrete pond system can support optimal tilapia growth. This study recommends the application of concrete ponds as an efficient aquaculture alternative, particularly in areas with limited land and resources. This system has proven to be adaptive to local conditions and contributes to increased productivity and income for aquaculture farmers.

Concrete roof tiles are an important material in building construction, particularly for roofing work, due to their advantages in terms of strength, durability, and material availability. This study aims to analyze two main physical characteristics of concrete roof tiles, namely bending load and water absorption, using a literature review approach from various previous studies. Bending load refers to the material's ability to withstand bending forces, while water absorption describes the material's capacity to absorb and store water through its pores. These two properties significantly influence the quality and durability of roof tiles in facing external environmental conditions, especially wet-dry cycles and mechanical loads. The results of the literature review indicate that the use of waste as an aggregate substitute in concrete mixes can significantly improve the performance of concrete roof tiles. For example, research using broken roof tiles and ceramic waste as aggregate substitutes successfully increased flexural strength to a range of 12.5–15.0 MPa. Meanwhile, variations in water absorption were recorded in the range of 4%–8%, depending on the material composition and production method. This proves that the use of recycled materials not only supports sustainability but also improves the mechanical and physical properties of concrete roof tiles. Overall, this study underscores the importance of material innovation in concrete roof tile production, particularly utilizing waste as an alternative aggregate. However, further research is needed to explore the best combination of materials and production techniques for producing high-quality, efficient, and environmentally friendly concrete roof tiles.

The development of transportation infrastructure in Indonesia continues to be prioritized to enhance regional connectivity, including the maintenance and replacement of bridges that have exceeded their service life. The Semut Bridge in Surabaya, originally a three-span reinforced concrete girder bridge, has experienced structural deterioration due to corrosion and the presence of a central pier obstructing river flow. These conditions have reduced hydraulic capacity, increased sedimentation risk, and heightened the potential for flooding. This study redesigns the Semut Bridge by converting the existing structure into a single-span Howe truss steel bridge. The load analysis refers to SNI 1725 using the Load and Resistance Factor Design (LRFD) method, while structural modeling was carried out both manually and with SAP2000 software. The planning includes the vehicle deck slab, composite girders, main truss members, connections, elastomeric bearings, and abutments. The results show that the bridge deck uses a 20 cm thick reinforced concrete slab with a one-way reinforcement system. Composite girders employ WF profiles, connections use shear connector studs with 25 mm diameter, and the main truss members adopt WF 900×300×16×38 profiles. The total concrete volume required is 282.6 m³, and the estimated steel demand reaches 122,383.79 kg. The single-span design eliminates the central pier, thereby improving river flow capacity while providing a structurally efficient, durable, and easily maintained solution.