JURNAL TEKNIK SIPIL CENDEKIA (JTSC)

Experimental Study of the Effect of Fly Ash and Andesite Ash Composition Variation on the Compressive Strength of Geopolymer Mortar

Nanda Agustin — 2026-05-29

Geopolymers are one of the innovative materials currently being developed as a substitute for portland cement as a binder. CoMPared to Portland cement-based mortar, geopolymer mortar offers advantages such as relatively low carbon emissions, competitive compressive strength potential, and good chemical resistance. The method used in this study involved test specimens measuring 5 × 5 × 5 cm³ using room temperature curing. The binder mixtures used consisted of fly ash and andesite ash, with five different ratios: 70% FA : 30% ABA; 50% FA : 50% ABA; 30% FA : 70% ABA; 0% FA : 100% ABA and 100% FA : 0% ABA. The activator solution used a ratio of Na₂SiO₃ : NaOH ratio of 2,5 : 1 with an 8 mol/L NaOH concentration. This study aimed to determine the optimum percentage ratio of fly ash and andesite ash mixture. The results showed that differences in binder composition affect the compressive strength of the geopolymer mortar. The optimum compressive strength of all test specimen variations was obtained in the 70% FA : 30% ABA variation, at 17,07 MPa at 28 days. These findings indicate that fly ash can accelerate the geopolymerization process, while andesite ash function as an additive that helps make the mortar structure denser.

The Effect Of Red Brick Powder And Teak Wood Ash Powder Fillers On Marshall Characteristics

Novi Nirmala Putri — 2026-05-29

Road pavement really needs a mixture of asphalt that has good durability and stability, because roads have an important role in the transportation system to support economic growth and community mobility. This study aims to analyze the effect of the use of Red Brick Powder and Teak Wood Powder Ash as a substitute for fillers on AC-WC asphalt mixtures. With the increasing amount of red brick powder and teak wood powder ash and has not been utilized optimally, there is a need for innovation in the use of environmentally friendly alternative materials. The method used in this study is Marshall testing to determine the characteristics of the mixture, such as stability, flow, VIM, VMA, and VFA with different filler content variations. The filler variation used in this study was 0%, 5%, 7% with a ratio of 80 : 20. The results showed that the 7% filler variation provided the most optimal mixture characteristics with a VIM value of 4.89% and a VMA of 15.89% which still met the required specifications. In addition, the values of stability, flow, VFA, and Marshall Quotient are also within the standard limits. Based on these results, red brick powder and teak wood ash have the potential to be used as filler alternatives to AC-WC mixtures that are more environmentally friendly.

Systematic Literature Review: Regulatory Uncertainty and Its Impact on Hospital Project Performance

Jasran Asya — 2026-05-29

Hospital infrastructure projects are inherently complex due to their exposure to dynamic healthcare regulations, fiscal constraints, long-term financing arrangements, and technological innovation. Regulatory uncertainty has emerged as a critical institutional factor influencing project performance; however, its impact within hospital projects remains insufficiently synthesized. This study employs a Systematic Literature Review (SLR) following PRISMA 2020 guidelines, searching exclusively through Google Scholar, to analyze 19 peer-reviewed studies published between 2022 and 2026 that examine the relationship between regulatory uncertainty and project performance. The findings indicate that 42.1% of the reviewed studies report a positive association between regulatory uncertainty and cost overruns, while 36.8% identify significant links to schedule delays. The effect on quality outcomes is non-linear: some studies reveal quality deterioration due to time and budget pressures, whereas others demonstrate that stable and stringent regulatory frameworks enhance technical quality and accountability. These mixed findings suggest a regulatory–performance paradox, where regulatory volatility increases risk and inefficiency, but regulatory stability strengthens governance and long-term project sustainability. This study positions regulatory uncertainty as an institutional mediator that links governance structures, financing mechanisms, and project performance outcomes in hospital infrastructure development. The proposed conceptual framework offers important implications for policy design and risk management in healthcare infrastructure projects.

Statistical Analysis and Correlation Between Soil Density (Sand Cone) and Soil Bearing Capacity (Field CBR) in Reclamation Landfill (Case Study: Patimban Port Package 6)

Dhani Rulianto — 2026-05-29

Quality control in the Package 6 Patimban Port reclamation project greatly determines the stability of port operations. This study aims to analyze the correlation between the average soil density (Sand Cone) of layers 1–7 to the surface bearing capacity (Field CBR) of the subgrade and formulate a prediction model. Using a quantitative approach, this study analyzed 26 samples using simple linear regression without a constant (regression through the origin). The results of the analysis showed a very strong and positive correlation relationship with the value of R = 0.976. The resulting prediction model is Y = 0.141X with a coefficient of determination (R²) of 0.953. This proves that 95.3% of the variation in Field CBR values is significantly influenced by the average density of all layers of the landfill. These findings confirm that every 1% increase in average density increases the Field CBR by 0.141%.

Cost And Time Analysis Using Time Cost Trade Off (TCTO) In Order To Catch Up With Execution Time (Case Study: Jakarta Islamic Hospital Pondok Kopi Construction Project)

Thesa Nurshela — 2026-05-29

In a construction project, there are three crucial aspects to consider, namely time, cost, and quality. The implementation of the Jakarta Islamic Hospital Pondok Kopi construction project faces several obstacles, especially at the stage of foundation structure and concrete structure work. Based on observations at the location, it is estimated that the completion of the construction of the Jakarta Islamic Hospital Pondok Kopi will be delayed or not in accordance with the planned schedule. There are several options that can be used to speed up project activities, including increasing working hours (overtime), adding manpower, adding or changing tools, adding more effective work methods, and other options. Of the several available alternatives, this study will apply two alternatives, namely increasing working hours (overtime) and increasing labor using the Time Cost Trade Off (TCTO) method. The optimization alternative that has the most optimal or efficient total cost and duration is by adding 5 workers because the project duration becomes faster, even though there is an increase in cost, the addition is more optimal or efficient compared to other alternatives, as indicated by a time efficiency of 51,36% and a cost efficiency of -20,02%. This optimization result can be used as an acceleration option for the project party.

Development of an SNI-Based Earthquake-Resistant Miniature House Model as a Structural Educational Medium

Rahmat Eki Putra — 2026-05-29

Indonesia is a country with high earthquake activity and earthquake-resistant buildings are needed. Residential building capabilities are required to remain safe during earthquakes is no longer merely a technical discourse, but a real need that touches people's daily lives. This study uses the R&D (Research and Development) research type with the object of research being a simple house miniature media based on SNI 2847:2019. The validity of the SNI-based earthquake-resistant house miniature model as a structural education medium is in the valid category. The validation results by material experts show an average value of 0.82 with a valid category, while the validation results by media experts show an average value of 0.93 which is also in the valid category. Thus, the developed learning media has met the eligibility criteria for use in the Basic Practice of Stone and Concrete course. The practicality level of the SNI-based earthquake-resistant house miniature model as a structural education medium is in the very practical category. This is indicated by the results of the student response questionnaire which obtained an average value of 97%, which indicates that the learning media is easy to use, useful, and able to support the practical learning process.

Sustainable Self-Compacting Concrete: The Role of Limestone Powder as A Cement Replacement

Muhammad Ramdhan Olii — 2026-05-29

The excessive use of cement in concrete production contributes significantly to environmental impacts, particularly CO? emissions. One potential solution is the partial replacement of cement with limestone powder in self-compacting concrete (SCC). This study aimed to investigate the effect of limestone powder as a partial cement replacement on the fresh properties and compressive strength of SCC. Limestone powder was used at replacement levels of 0%, 6%, 9%, 12%, and 15% by weight of cement. The fresh properties of SCC were evaluated using slump flow, V-funnel, and L-box tests, while compressive strength tests were conducted to assess hardened performance. The results showed that SCC mixtures containing up to 9% limestone powder satisfied the SCC workability requirements. The optimum performance was achieved at 6% limestone powder replacement, which produced a slump flow diameter of 600 mm and compressive strength of 29.58 MPa, exceeding the design strength target of 25 MPa. Higher replacement levels reduced both workability and compressive strength, with the 15% mixture failing to meet acceptable performance criteria. These findings indicate that limestone powder can be effectively utilized as a sustainable partial cement replacement in SCC at moderate replacement levels while maintaining satisfactory fresh and hardened properties.

GIS-Based Spatial Distribution and Distance Analysis of Public Facilities at Lampung State Polytechnic

Emmi Desniati Desniati — 2026-05-29

The spatial distribution of campus facilities is a critical determinant of the efficiency of spatial planning in higher education institutions. This study examines the spatial distribution pattern of campus public facilities using the Average Nearest Neighbor (ANN) method within a Geographic Information System (GIS) framework. The study was conducted at Lampung State Polytechnic using centroid point data of buildings with a total study area of 202,943.98 m². The analysis yielded a Nearest Neighbor Ratio (NNR) of 0.884, indicating a tendency toward spatial clustering. However, this tendency was not statistically significant at the 95% confidence level (Z-score = ?1.567; p = 0.117 > 0.05), and the building distribution is therefore classified as random. Inter-building distance analysis revealed that the observed mean distance (28.16 m) is approximately 11.6% shorter than the expected distance under a random distribution (31.85 m), suggesting that contextual factors—including land constraints, functional connectivity requirements, incremental development patterns, and utility network efficiency—have collectively influenced building placement. The predominantly random distribution pattern reflects a process of adaptive spatial development conducted without reference to a comprehensive spatial master plan, which may give rise to circulation inefficiencies, utility integration challenges, and suboptimal open space utilization. This study demonstrates that GIS-based spatial statistical analysis affords an objective, quantitative evaluation of campus spatial planning and can serve as a scientific basis for the formulation of more structured, data-driven facility development policies.

Seismic Response and Liquefaction Control on Sloping Ground Using Groundwater Lowering Strategy

Rinarebut Rayhansah — 2026-05-29

Liquefaction-induced slope failure remains a critical geotechnical problem in seismic regions, particularly under saturated sloping ground conditions. This study investigates the effects of slope inclination and groundwater depth on liquefaction behavior using numerical simulation under seismic loading. Three slope configurations (i1–i3) and two groundwater conditions, W2 (3.84 m) and W3 (9 m), were analyzed to evaluate excess pore water pressure (EPP), seismic amplification, spectral response, and lateral deformation. Results show that steeper slopes and deeper groundwater conditions significantly modified soil dynamic behavior. Peak acceleration increased from 0.127 g under i1–W2 to 0.190 g under i3–W3, while the dominant spectral period shifted to T ? 1.443 s with maximum spectral acceleration reaching Sa,max ? 0.529 g. Groundwater lowering (GL) effectively reduced pore pressure generation and produced nearly drained conditions within the computational zone. However, the Encased Stone Column (ESC) system provided better performance in minimizing lateral deformation and liquefaction-induced flow displacement. These findings demonstrate that hydraulic control and reinforcement systems play complementary roles in improving the stability of liquefaction-prone sloping soils under earthquake loading.

Analysis Of The Axial Bearing Capacity And Settlement Of Bored Pile Foundations Using The Finite Element Method (Case Study: Construction Of The Sumatera Main Stadium)

Annisa Suci Rizky — 2026-05-29

Bored pile foundations are one type of deep foundation used to support axial loads in building construction. This study aims to analyze the ultimate bearing capacity and settlement of a single bored pile foundation in the North Sumatra Main Stadium Project located in Batang Kuis District, Deli Serdang Regency, North Sumatra Province. The analysis was carried out on a bored pile with a diameter of 80 cm using three methods, namely the Chin Method, the Mazurkiewicz Method, and the Finite Element Method (FEM). The data used in this study were obtained from the Static Loading Test (SLT).The results indicate differences in the ultimate bearing capacity (Qu) and foundation settlement values produced by each method due to variations in their approaches to interpreting the load-settlement relationship. The Chin Method produced the highest Qu value of 617 tons with a settlement of 75 mm, indicating a more optimistic result and serving as the upper bound. The Mazurkiewicz Method produced a Qu value of 590.65 tons with a settlement of 60 mm, while the FEM analysis produced a Qu value of 600 tons with a settlement of 65 mm. Based on these results, the Mazurkiewicz Method is considered sufficiently representative because it provides values between conservative and optimistic approaches. Therefore, the use of more than one analysis method is highly recommended to obtain more accurate and reliable results in bored pile foundation design.

Analysis Of Drainage Channel Capacity On Prof. M. Yamin Street In Pontianak

Imanuel Kemenangenta Perangin Angin — 2026-05-29

Surface runoff results from precipitation that is not absorbed or infiltrated into the soil due to water-saturated soil conditions. If left uncontrolled, surface runoff can cause puddles or flooding that may disrupt human activities and the environment. In this study, the research site was located on Prof. M. Yamin Street in the city of Pontianak. In the current study, Prof. M. Yamin Street in Pontianak already has a drainage system; however, the performance of this drainage system’s capacity needs to be analyzed. The method used to analyze the performance of the drainage system on Prof. M. Yamin Street involves comparing the existing drainage capacity against the surface runoff discharge resulting from the average daily maximum rainfall using the rational method and hydraulic analysis. In the analysis of the drainage system on Prof. M. Yamin Street, the drainage system’s capacity is no longer sufficient to accommodate the surface runoff flow rate of 1.1691 m³/s, therefore, it is necessary to modify the dimensions of the drainage channels using hydraulic analysis with a width (B) of 1.4 meters, a channel depth (H) of 0.557 meters, and a channel bank height (W) of 0.528 meters on both sides of Prof. M. Yamin Street.

A Stabilized Modified Lax Scheme with Numerical Filter for Accurate One-Dimensional Pollutant Transport Modeling

Qalbi Hafiyyan — 2026-05-29

Pollutant transport in water is a global issue commonly modeled using advection-diffusion equations that describe transport driven by concentration gradients and flow velocity. Because analytical solutions are limited to simple cases, numerical methods are essential for simulating pollutant transport. However, many existing numerical models require complex formulations to achieve accurate, stable solutions. This study proposes a one-dimensional numerical model based on a modified Lax scheme combined with the Hansen filter, providing stable, accurate solutions with a simpler formulation. The proposed model is evaluated using three test cases: pure advection, advection-diffusion, and a Gaussian pulse. The performance of the proposed numerical model is compared with the exact solution using L₂, L_?, and absolute error analysis. For the pure advection case, the proposed model achieves L₂=0.048 and L_?=0.011, which are lower than those reported by some previous numerical models. In the advection-diffusion case, the model also has better accuracy than some previous numerical models with L₂=0.0948 and L_?=0.0422. For the Gaussian pulse case, the absolute error remains very small at 8.76 × 10^-5 at the concentration peak. show that the proposed model can suppress numerical oscillations while maintaining high accuracy and efficiency, making it effective for one-dimensional simulations of pollutant transport.

Implementation Of The Construction Safety Management System (Smkk) For Soft Soil Road Improvement Works At Km 28 Batuah, Kutai Kartanegara

Yanti Yanti — 2026-05-29

This study discusses the implementation of the Construction Safety Management System (SMKK) in road construction work on soft soil at KM 28 Batuah, Kutai Kartanegara Regency, East Kalimantan. The study aims to analyze geotechnical parameters and construction safety risks under soft soil conditions. The research variables include California Bearing Ratio (CBR), settlement, slope stability, probability, severity, and construction work risk levels. The research methods consisted of field observations, laboratory testing, literature review, and risk analysis using the HIRADC approach within the SMKK framework. The results showed that the soil CBR value ranged from 3–5%, field settlement reached 30–80 cm, and the slope safety factor under saturated conditions was less than 1.0, indicating unstable conditions. Risk analysis identified the main hazards as slope failure, heavy equipment sinking, surface deformation, and occupational accidents, with medium to high risk levels. The probability level was categorized as frequent due to high rainfall intensity, poor drainage conditions, and heavy traffic loads. The implementation of SMKK through technical and administrative controls, personal protective equipment, geotechnical monitoring, and emergency response systems is necessary to minimize occupational accidents in road construction on soft soil.

Evaluation of Arterial Roads in the SWK Tegalega Area of Bandung City

Ina Revayanti Revayanti — 2026-05-29

The arterial roads in the SWK Tegalega area play a vital role in the spatial structure of the city of Bandung; however, the dynamics of massive development often result in discrepancies between existing conditions and established spatial plans. This study evaluates the suitability of land use and arterial road infrastructure in the Tegalega Urban Sub-District based on the Bandung City Planning Line Map (Grand Design). The primary focus is to assess and update the geometric plans for urban facilities and infrastructure to ensure alignment between spatial policies and existing conditions on the ground, given the high intensity of land-use conflicts along this major corridor. The research method used is a Geographic Information System (GIS)-based superimposition method, which compares existing spatial data from field observations with City Planning Line regulations. Evaluation parameters include road width, road right-of-way (Rumija), and building boundaries. The results of this evaluation serve as a validation tool for communicating urban planning information and form the technical basis for issuing recommendations on Spatial Planning Activity Compliance (KKPR) and approving site plans. Through this update of geometric data, it is hoped that legal and technical certainty will be established in the planning of arterial roads, supporting sustainable urban mobility and minimizing future spatial planning violations.

Project Risk Mapping with Small-Qualified Contractor Partners

Sutikno Sutikno — 2026-05-29

Project risk mapping is a strategic step that must be undertaken by the Government of Southwest Papua to ensure that public expenditures are properly allocated and produce tangible benefits for the community. The implementation of Presidential Regulation (Perpres) No. 17 of 2019 concerning Special Autonomy provides opportunities for the growth of local entrepreneurs, which is expected to positively impact the regional economy in Sorong, Southwest Papua. Therefore, risk-based project evaluation is necessary to support good governance practices. This study aims to identify and map the risks faced by the government in implementing projects involving small-qualified contractors in Southwest Papua. Using a quantitative approach through questionnaire distribution to 50 respondents, the study produced a mapping of project risks associated with small-qualified contractor partners that need to be anticipated by the government, along with mitigation efforts to minimize potential risks. The findings of this study provide insights for the government in formulating strategic measures to reduce project risks and enhance the capacity of small-qualified contractors, thereby supporting the implementation of Presidential Regulation No. 17 of 2019 through accountable and transparent governance mechanisms.

Analysis Of Rainfall Distribution Using Log-Pearson Type III

Raymond Pasaribu — 2026-05-29

Rainfall frequency analysis is essential for determining design rainfall and flood discharge in hydraulic structure planning. In this study, annual maximum rainfall data were evaluated using statistical parameters—including the coefficient of variation, skewness coefficient, and kurtosis coefficient—to determine the most suitable probability distribution. The Log-Pearson Type III distribution was selected as it best represented the historical data patterns. Design rainfall values for various return periods were subsequently computed to construct Intensity-Duration-Frequency (IDF) curves. Watershed delineation was performed to identify the physical characteristics of the river basin, allowing the transformation of design rainfall into peak flood discharges. The results demonstrate that longer return periods consistently yield higher rainfall intensities and peak discharges. Ultimately, this study provides critical hydrological parameters required for effective drainage design and regional flood control.