REKONSTRUKSI TADULAKO: Civil Engineering Journal on Research and Development

Karakteristik Campuran Beton Aspal (AC-WC) Menggunakan Pasir Pantai sebagai Pengganti Agregat Halus

Syukuriah Syukuriah, Andi Isdyanto — Fri, 28 Aug 2026 00:00:00 +0000

Massive road infrastructure development requires a large supply of fine aggregate (sand), which often comes from conventional sources such as river or land quarries. Excessive exploitation of these sources leads to environmental problems, including ecosystem damage and changes in river morphology. This study aims to evaluate the characteristics of asphalt concrete wearing course (AC-WC) mixtures by utilizing beach sand as an alternative fine aggregate, while also identifying its potential as an eco-friendly solution. The research employed an experimental laboratory method. Beach sand from Binuang was used as a 100% substitute for standard fine aggregate. The quality of both coarse and fine aggregates was tested in accordance with SNI (Indonesian National Standard) standards. Subsequently, AC-WC mixtures were prepared at a predetermined optimum asphalt content (OAC) of 6.5%, and their Marshall characteristics were tested, including stability, flow, voids in the mix (VIM), voids filled with asphalt (VFA), and voids in mineral aggregate (VMA). The results indicate that the use of beach sand as a fine aggregate substitute to a certain percentage can meet the AC-WC mixture specifications required by Bina Marga (the Directorate General of Highways). The mixture with this optimal substitution percentage demonstrated the best Marshall characteristics, which remained within the specified range. At this percentage, the stability value reached 842 kg, flow 3.67 mm, VIM 4.12%, VMA 17.97%, VFA 77.23%, and Marshall Quotient (MQ) 233 kg/mm. These values demonstrate that the mixture has adequate performance. In conclusion, beach sand has the potential to be used as a partial substitute for fine aggregate in AC-WC mixtures, particularly at an optimal replacement percentage. The utilization of beach sand not only provides an abundant alternative material but also contributes to reducing the exploitation of conventional aggregates, making it a more economical and environmentally friendly solution for road infrastructure development. The novelty of this research lies in the identification of the optimum conditions for the use of beach sand as a substitute for fine aggregate in AC-WC mixtures based on a comprehensive evaluation of Marshall parameters. The results of the study indicate that although some mixtures meet stability, failure in volumetric parameters such as VIM and Marshall Quotient can still cause the mixture to be unsuitable. This study confirms that beach sand can be used as an alternative fine aggregate if used in certain proportions that are able to produce a balance between strength, flexibility, and density of the mixture

Analisis Kuat Tekan dan Lentur Beton dengan Substitusi Sebagian Agregat Halus Menggunakan Pasir Pantai

Atur Parhorasan Nusantara Siregar, Egi Hendrawan — Sun, 30 Aug 2026 00:00:00 +0000

This study aims to analyze the effect of adding beach sand from the Matano area in Bungku Tengah District, Morowali Regency on the mechanical properties of concrete, particularly its compressive strength and flexural strength. In addition, the research is intended to determine the optimal percentage of beach sand that can be used as a partial substitute for fine aggregate, thereby effectively improving the mechanical performance of concrete.This study employs an experimental quantitative approach with analysis of variance (ANOVA). The research variables include the percentage of fine aggregate substitution (25%, 50%, 75%, 100%) and the treatment of beach sand washing (washed and unwashed). The test specimens consist of cylinders measuring 150 mm × 300 mm and reinforced beams measuring 1500 mm × 100 mm × 150 mm, all of which were cured by immersion for 28 days before being tested for compressive strength and flexural strength.The results show that the use of fully washed beach sand as a complete replacement for fine aggregate does not significantly reduce the quality of concrete. The best performance was achieved at 100% substitution, with a compressive strength of 26.65 MPa, a flexural strength of 19.82 MPa, a maximum deflection of 1.61 mm, and normal cracking. This indicates that properly washed beach sand is suitable for full use as fine aggregate in concrete

Karakteristik Marshall Campuran Aspal Emulsi Dingin Menggunakan Fly Ash Sebagai Filler

Ajeng Aissah, I Dewa Made Alit Karyawan, Ratna Yuniarti, Hasyim — Sun, 30 Aug 2026 00:00:00 +0000

Filler is a fine material that plays a crucial role in determining the performance of asphalt mixtures by influencing their physical and mechanical properties. This study aimed to evaluate the use of fly ash as an additional filler to enhance the performance of Cold Emulsified Asphalt Mixtures (CAED). An experimental method was employed through Marshall testing. The study involved material characterization, determination of the Optimum Residual Asphalt Content (KARO), and evaluation of the Marshall characteristics of CAED containing fly ash at replacement levels of 0%, 25%, 50%, 75%, and 100% by filler weight. A total of 15 specimens with a filler blend consisting of 50% fly ash and 50% stone dust were prepared to determine the KARO, followed by 15 additional specimens to evaluate the Marshall characteristics of each fly ash variation. The results demonstrated that the fly ash content significantly influenced the Marshall characteristics of CAED. Based on compliance with the applicable specifications, the optimum fly ash content was 50% of the total filler weight, which resulted in a balance of volumetric properties (VIM 3.56%; VMA 23.43%; VFA 84.93%) and mechanical properties (stability 658.4 kg; MQ 259.80 kg/mm). Meanwhile, the mixture containing 25% fly ash exhibited the best mechanical performance with the highest stability value among other fly ash variations (758.45 kg) and an MQ of 264.39 kg/mm. The addition of fly ash as a filler has been shown to improve the characteristics of Marshall CAED when compared to mixtures without fly ash. Further research is recommended to evaluate its long-term performance through the Wheel Tracking Test

Evaluasi Struktur Bangunan Eksisting Gedung Dinas Pendidikan dan Kebudayaan Kota Palu dengan Analysis Linear Static Procedure Method

Rahmania Rahmania, Hilda Listiawaty, I Ketut Sulendra — Thu, 03 Sep 2026 00:00:00 +0000

The Palu City Education and Culture Department Building, as a critical facility following the 2018 Palu earthquake, requires a structural performance evaluation to ensure its safety against future seismic hazards, considering its proximity to the Palu-Koro Fault. This study aims to evaluate the existing structure using the ASCE/SEI 41-17 standard. The evaluation methodology commenced with a Tier 1 screening process based on quick checks, with a performance objective of Collapse Prevention (CP) at the BSE-2E hazard level. Subsequently, a three-dimensional structural analysis using software ETABS was conducted to verify serviceability and strength performance (Demand Capacity Ratio/DCR) under load combinations in accordance with SNI 2847:2019 and SNI 1726:2019. The Tier 1 evaluation results indicated critical deficiencies, including the building’s location within a surface fault rupture zone, potential overturning instability, excessive column axial and shear stresses, failure of the strong-column weak-beam principle, and inadequate transverse reinforcement detailing. ETABS analysis results showed that the maximum deflection (16.977 mm) still satisfied the allowable limit of l/240. However, the strength analysis revealed massive failure: 100% of columns were over stressed with a maximum DCR of 10.165; 211 beam elements possessed actual capacities lower than the required reinforcement demand; and floor slabs failed to meet bending capacity requirements. It is concluded that the existing structure does not meet the Collapse Prevention performance level requirements and declared unsafe, thus necessitating comprehensive structural retrofitting

Analisis Penggunaan Material Sungai Paneki - Pombewe Sebagai Bahan Timbunan Pilihan dan Lapis Pondasi Bawah

Thu, 03 Sep 2026 00:00:00 +0000

Up to now asphalt road still become main selection in the construction of infrastructure in Central Sulawesi Province, besides because of ease to get material. This is also caused by roads as the most important facility of transportation to support the fluency of land communication and economic growth of one region. The objectives of this research is to find out characteristic of material of Paneki-Pembewe river at Pembewe village, district of Sigi Biromaru, Sigi regency Palu city. To find out whether material at Paneki- Pembewe river can fulfill specification of Bina Marga 2018 as selected heap material and low layer of foundation. By data resource and information from visual observation at the field testing would be carried out at the Laboratorium. The testing that is meant is testing of physical soil, among them abration, filter analysis, kind of heavy, melted limit, index of plasticity, lempung clod with testing of mechanic such as testing of density and testing CBR (California Bearing Ratio). Research findings show that material of Paneki- Pembewe river can be used as selected heap material and low layer of foundation of road density, this is based on on the CBR value. Selected heap obtained over 10 x pounding is 0,1" with average =6,42%,02" -8,73%, 35 x pounding is 0,1" 13,90%, 0,2" 18,18%, 65 x pounding is 0,1"- 18,45%,0,2" 22,63% and CBR low layer of foundation which is obtained over 10x pounding is 0,1" 20,05%, 0,2"-25,66%,35 x pounding is 43,84%, 0,2"= 52,93%, 65 x pounding is 0,1"=52,93%, 0,2" = 68,08%, so that the result of testing of Paneki-Pembewe river material indicated that those materials fulfill requirement of specification of Bina Marga 2018 as selected heap material and low layer of foundation

Evaluasi Kerusakan Groundsill dan Rekomendasi Mitigasi AwaSl Berdasarkan Survei Pesawat Udara Nirawak dan Analisis Model Elevasi Digital

Aqbil Fauzan, Muhammad Heru Sukoco, Puji Harsanto — Fri, 04 Sep 2026 00:00:00 +0000

The collapse of the Srandakan groundsill on the Progo River caused riverbed degradation and triggered headward erosion that potentially threatens the stability of the new Srandakan Bridge. Unstable post-collapse field conditions limited the use of conventional terrestrial surveys to obtain damage geometry data quickly and safely. This study evaluated damage to the Srandakan groundsill through the integration of Unmanned Aerial Vehicle (UAV) surveys, GNSS control, and Digital Elevation Model (DEM) analysis, applying a relative risk classification among piers based on geometric indicators, given the unavailability of pier foundation depth data. Unlike previous UAV-DEM studies that focused on post-earthquake damage mapping or riverbank erosion characterization, this study represents one of the first applications of this approach specifically to post-collapse groundsill damage evaluation. Accuracy testing yielded a CE90 of 0.052 m and an LE90 of 0.066 m, meeting Class 1 standards of the Geospatial Information Agency Regulation. Results showed the lowest riverbed elevation reached 3.23 m, a decrease of 7.12 m from the reference elevation of 10.35 m, with headward erosion identified extending approximately 250 m toward the new Srandakan Bridge. The relative risk classification indicated that Pier 6 fell into the highest risk category, followed by Pier 7 (moderate) and Pier 8 (moderate-low), while Pier 5 could not be classified using the vertical indicator due to its position at the edge of the active channel. These findings form the basis for preliminary mitigation recommendations prioritizing high-risk piers, serving as an initial basis prior to further hydraulic studies and structural design

Evaluasi dan Redesain Fondasi Abutment akibat Tiang Bor Tidak Mencapai Kedalaman Rencana: Studi Kasus Jembatan Palu 4

Tue, 08 Sep 2026 00:00:00 +0000

Failure of a bored pile to reach its planned depth due to construction problems may alter pile capacity and load distribution within the pile group, requiring an integrated geotechnical and structural assessment. This study presents a case study of the evaluation and redesign of the Palu 4 Bridge abutment foundation, where bored pile No. 5 experienced borehole collapse and reached only about one-third of its planned depth. The remedial scheme introduced replacement pile No. 7 and enlarged the pile cap from 12.8 m × 8.1 m to 16.7 m × 8.1 m. Pile-group response was analyzed using Ensoft GROUP to evaluate axial force, lateral displacement, shear, and bending moment, while CSI SAFE was used to assess pile-cap flexure, one-way shear, and punching shear. The maximum lateral displacement was 21.50 mm, below the 25 mm limit, while the axial safety factor of 2.425 exceeded the minimum requirement of 1.67. The governing bored-pile demand-to-capacity ratio was 0.877 for flexure, whereas the pile cap reached 0.985 for flexure and approximately 0.87 for punching shear. This study demonstrates an integrated geotechnical–structural evaluation procedure to verify the adequacy of a remedial foundation configuration when a bored pile fails to reach the planned depth

Analisis Tekuk Nonlinier (Nonlinear Buckling) pada Struktur Fleksibel Tinggi (Highly Flexible Structures)

Anwar Dolu, Amrinsyah Nasution, Agus Rivani — Tue, 22 Sep 2026 00:00:00 +0000

In contemporary construction engineering, many structural systems adopt slender and flexible models known as Highly Flexible Structures (HFS), as a result of efforts to minimize structural dimensions and weight while improving efficiency and aerodynamic design. This study examines the nonlinear buckling phenomenon in cantilever structures. The analytical solution for the nonlinear buckling case is obtained by solving the first and second kinds of elliptic integrals. The values of the elliptic integrals are computed using the open-source software R (RStudio). The analysis results under nonlinear buckling conditions show that the critical load obtained is greater than the Euler critical load at the onset of initial buckling, also referred to as the post-buckling load. The critical load is P=4,315EI/L^2, with a maximum lateral deflection of xmax=0,8063.L , and axial deflection of dy=0,1947.L . Based on the load–lateral displacement (x-direction) curve during the post-buckling stage, the load increases beyond the Euler buckling load while the lateral displacement decreases after reaching the maximum lateral deflection. In contrast, the load–axial displacement curve shows that displacement tends to increase proportionally with increasing load.

Seismic Response and Pile Foundation Efficiency of an Irregular Hospital Building with Double Friction Pendulum System

Thu, 24 Sep 2026 00:00:00 +0000

Hospital buildings are essential facilities that require adequate seismic performance to maintain post-earthquake functionality. This study evaluates the influence of a Double Friction Pendulum System (FPS) on the seismic response and pile-foundation demand of a nine-story irregular hospital building in Malang, Indonesia, designed in accordance with SNI 1726:2019. Fixed-base and FPS models were analyzed using a 5% damped response spectrum, with structural performance assessed through fundamental period, base shear, lateral displacement, interstory drift, and isolator displacement. Pile-foundation demand was evaluated from the governing support reactions, while the axial resistance of 600 mm prestressed concrete spun piles was determined from subsurface investigation data using the Décourt method. Foundation efficiency was quantified based on the total installed pile length required by each structural alternative. The FPS increased the dominant structural period to 3.063 s in the X direction and 2.580 s in the Y direction and reduced average interstory drift by 73.6–81.7% and 42.8–83.3%, respectively, relative to the fixed-base alternatives. The maximum resultant isolator displacement was 70.64 mm, corresponding to approximately 31.9% of the design displacement capacity of 221.11 mm. The FPS alternative reduced the total installed pile length from 4692 m to 1800 m, indicating a potential foundation-efficiency improvement of 61.63% under the adopted structural and geotechnical assumptions. The main contribution of this study is the integration of seismic-isolation performance with pile-foundation demand for an irregular essential building. Further verification through detailed pile-capacity, settlement, pile-group, and soil–pile–structure interaction analyses is recommended

Analisis Daya Dukung Fondasi Tiang Pancang menggunakan Metode Analitik dan Metode Elemen Hingga

Sat, 26 Sep 2026 00:00:00 +0000

Pile foundations are one type of deep foundation widely used in high-rise building construction and heavy infrastructure, especially in areas with low-bearing soil conditions. This study aims to analyze the ultimate bearing capacity (Qult) of axial and lateral piles using analytical methods, finite element methods (FEM), and comparing them with the results of static axial load tests in the field. The data used includes SPT test results, laboratory data, and static load test (SLT) results. The analytical methods include the Meyerhof and Alpha approaches for axial bearing capacity and the Broms method for lateral bearing capacity. FEM modeling was performed using 2D FEM software. Soil interpretation from BH-1 and BH-3 indicates the presence of soft clay layers up to a depth of 22–24 m with a layer of dense sand below. SLT indicates TP-03 has the lowest Qult (190 tons), but analytical analysis shows the highest Qult (279 tons). Elastic settlement at all test points remains within safe limits based on the Vesic approach. Lateral Qult at all piles demonstrates good performance against 12 mm and 25 mm deflections, with optimal performance at TP-03 and TP-05. FEM analysis shows the maximum settlement at TP-03 (18.04 mm) and the highest axial Qult at TP-05 (201 tons), with a safety factor >2 for all piles. FEM provides the closest estimate to field test results (SLT), while the analytical method yields higher values. In lateral analysis, the analytical method showed larger results than FEM, with the largest difference of 212.35 kN on TP-03. This study provides an important contribution to the selection of analysis methods and pile foundation design on low-quality clay soil