On-site sanitation systems and fecal contamination in shallow groundwater in urban Indonesia: assessing influence of distance and rainfall variables Gita L. Putri, Akna M. Ilmi, Rahayu Handayani, Dadang Iskandar, Cindy R. Priadi, Juliet Willetts, Tim Foster Water Research, 2025 Over 41 million people in urban Indonesia self-supply drinking water from private wells. However, unsealed on-site sanitation systems (OSSs) located near these groundwater sources raise concerns about fecal contamination. While previous research has discussed on-site sanitation system (OSS)-related risks, limited studies have quantitatively examined how lateral and vertical distance between OSS and groundwater sources influence contamination risk using a clear source-pathway-receptor model. The effects of climatic variability, particularly rainfall, also remain poorly understood. Given the widespread use of wells and OSSs in Indonesia, understanding these factors is essential for developing evidence-based water and sanitation policies. A year-long field study was conducted in Metro, Indonesia, to investigate how fecal bacteria from OSS migrate into groundwater. Seventeen piezometers, each 10 meters deep, were constructed at three sites. At each site, piezometers were arranged in cruciform pattern, located at two distances (2 m; 5 m) from the existing OSSs. Water samples were collected monthly, with more frequent sampling during one month of the wet season. Results showed that Escherichia coli (E. coli) contamination exhibited temporal variation, increasing during the rainy season. A seasonal flush was observed at its onset of the rainy season. This was marked by an approximate 2-log increase in E. coli levels, rising from 3 to 199 MPN/100 ml in the nearest piezometer and from 5 to 461 MPN/100 ml in the farthest piezometers. The number of heavy rain days and cumulative rainfall over a 3-day lag period significantly increased the odds of E. coli contamination. Over a 7-day lag period, only total rainfall remained significant. Greater horizontal and vertical distance between the OSS and groundwater significantly reduced the likelihood of E. coli contamination, with the impact of horizontal distance being more pronounced during wet months. These findings highlight the importance of vertical distance in sanitation-groundwater interaction, especially during wetter months. Incorporating vertical distance into latrine siting guidelines is recommended to reduce microbial contamination risk in groundwater and improve public health for millions relying on self-supplied water.
Reuse of Construction Waste for Sustainable Development Dadang Iskandar, R. Jachrizal Sumabrata, Eri Prawati, Yusuf Amran, M. Nurkholid Civil Engineering and Architecture, 2023 The use of natural aggregates in the manufacture of concrete, if carried out continuously, can result in a crisis in the availability of natural materials. This should be of concern to all of us because natural resources must be maintained in a sustainable manner. This study aims to utilize construction waste from the demolition of rigid pavement roads on the Trans-Sumatra toll road. One of the main parameters in the design of concrete structures is compressive strength. The compressive strength value in this study is the result of a combination test of a mixture of RCA and natural aggregate (NA) with 3 compositions of RCA coarse aggregate mixture, namely: 30%, 50%, and 70%, and the rest is filled using NA material and 4 compositions of water-cement ratio, namely 0.3; 0.4; 0.5; 0.6. The mix design used is based on SNI 7656: 2012 by modifying the need for coarse aggregate to be replaced with RCA. The test results show that at the age of 7 days, the concrete produces a compressive strength of 25.32 MPa; this achievement is obtained for the RCA composition of 50% and the water-cement ratio is 0.3, while at the age of 14 days, the concrete produces a compressive strength of 25.921 MPa obtained from the mixture. RCA 70% and water cement ratio 0.3. The phenomenon of increased strength at 70% RCA is indicated because the high quality of RCA produces relatively high new concrete, but the bonding process between aggregates is hampered because the cement paste still sticks to the RCA.
Scrutinizing the Effect of Water Temperature on the Compressive Strength of Recycled Concrete Dadang Iskandar, Ida Hadijah, Sigit P. Hadiwardoyo, Novia Lumintu Wati, Septyanto Kurniawan Civil Engineering and Architecture, 2023 After demolishing rigid roads and old buildings, concrete is often rendered worthless and thrashed as waste. Currently, sustainable concrete construction is very popular, and the goal of the industry is to protect the population's well-being by reducing CO<sub>2</sub> emissions and encouraging the effective use of natural resources. One of the causes of decreased quality of recycled products is the adherence of cement paste to concrete demolition. Therefore, this study aims to examine the effect of water temperature on the compressive strength of recycled concrete. This is carried out with the hope that water temperature can impact the disintegration of the cement paste in the demolition concrete, thereby strengthening the bond between aggregates. The water temperature applied in this study was 25℃, 60℃, and 100℃, while the levels of recycled concrete aggregate (RCA) used were 25%, 50%, and 80%. The results showed that the highest compressive strength was obtained with an average of 26.23 MPa at a water temperature of 25℃ and 25% RCA. However, this value is still below the composition of the natural aggregate, which is 28.6 MPa. Due to the rapid hydration caused by the high-water temperature, the process of forming concrete on the surface is accelerated while the interior remains weak. This situation affects the weakening of the compressive strength of concrete. Furthermore, this study shows that high water temperatures are beneficial for the cement paste decay process in recycled aggregates, but it is best to use a normal temperature of 25℃ when mixing the water.
Evaluation of the Sustainability Indicator for Road Infrastructure in Indonesia R. Jachrizal Sumabrata, Dadang Iskandar, Radhitya Abiyoga Civil Engineering and Architecture, 2022 The quality of road infrastructure in Indonesia is ranked 64th out of 137 countries studied behind Singapore which was placed 2nd, Malaysia 23rd, Brunei Darussalam 33rd, and Thailand 59th. Therefore, the main objective of this research was to analyze the sustainability indicators for the road infrastructures in the country and also to evaluate the effect of these indicators based on the perceptions of civil servants and contractors. The process involved conducting a literature review to identify the variables and indicators while a survey was used to gauge the perceptions of the respondents. The data obtained were analyzed using the Structural Equation Modeling with a Partial Least Square approach. The results showed the most influential indicator for existing and expected road infrastructures were road lighting with a loading factor of 0.904 and environmental assessment process with 1.000 respectively according to the government employees. Meanwhile, the construction company employees believed it was the environmental assessment process with 1.000 as well as pedestrian access, bicycle route, and public transportation with 1.000 respectively. The usefulness of this research is to produce indicators that can be used by infrastructure managers to improve their performance by seeking the development and maintenance of the right infrastructure so that it can be used according to the needs of the user.
The development of readiness indicators for transit-oriented areas Dadang Iskandar, R. Jachrizal Sumabrata, Radhitya Abiyoga Civil Engineering and Architecture, 2021 The diversion of people towards public transportation has become the main focus of the Central Government and this involves rearranging the areas traversed by mass transportation corridors through the concept of transit-based integration known as the Transit-Oriented Development (TOD) in order to overcome congestion problems in Greater Jakarta, especially the Jakarta area. However, these plans have raised concerns on the ability of the transit-oriented area to fully accommodate the TOD concepts and principles or just to serve as only a part of the property business owned by several parties. The implementation of the concept is also not optimal due to the lack of an appropriate tool to identify the readiness of an area to be developed into a transit-oriented area by the government and the actions required to unlock the potentials of the development. This research, therefore, used 22 indicators to determine whether an area fulfills the transit-oriented elements and the factors required for its preparation. This involved using literature studies to produce research variables after which a survey was conducted and tested for validity and reliability by the drafter, academics, experts, and practitioners. The indicators were developed into an assessment instrument consisting of 5 parts to represent the research variables and other 23 questions.
Temperature Effect on the Deformation of the Recycled Hot-Mix Asphalt Concrete with Nano Crumb Rubber as an Added Material with Wheel Tracking Machine S P Hadiwardoyo, R H Aryapijati, R J Sumabrata, D Iskandar Iop Conference Series Materials Science and Engineering, 2020 The use of materials for the construction of roads can be done by recycling asphalt concrete mixtures that have reached fatigue or aging conditions. The results from stripping the asphalt concrete layer on the surface layer can be reused after processing by recycling the material. The recycling process is often intended to preserve the environment from natural damage due to the processing of material for asphalt concrete mix. To improve the performance of the recycled mixture, additives have been widely used and the use of building materials as additives can also be obtained from building material waste. One of the waste that continues to increase is the waste of vehicle tires. In this research used tire waste that has been mashed up to Nano size. The use of finer used tire sizes is intended to facilitate the process of mixing with asphalt. Recycling performance of hot mix asphalt concrete on deformation performance has been used rutting test using Wheel Tracking Machine at a temperature of 27°C, 40°C and 60°C. The test results showed a decrease in the rate of deformation in the asphalt concrete recycle mixture using Nano crumb rubber added material.
Contribution of Nano Crumb Rubber on Recycled Asphalt Concrete As Pedestrian Paving Block S L Annisa, S P Hadiwardoyo, R J Sumabrata, D Iskandar Iop Conference Series Materials Science and Engineering, 2020 Stripping the road surface layers of asphalt concrete caused by various considerations that have been damaged by the aging process of asphalt. This stripping material will continue to grow in sufficient quantities if the recycling process is not utilized. The recycling process can be done by restoring the performance of asphalt or aggregate and can even occur both to meet the specifications required originally. In this research, asphalt concrete mixture has been used where the asphalt element has undergone an aging process so that it needs to be rejuvenated or softened. The addition of used oil has been used in the process of softening the hot Asphalt Concrete Wearing Course (ACWC) type. The process of increasing the performance of recycled blends has used Nano Crumb Rubber (NCR) material. The test results show that the ratio of the old asphalt content and used oil as a softener is obtained with a ratio of 11: 4 to obtain the required level of softening. This composition has produced a bitumen penetration value of 60, and the addition of NCR 2.5% and 5% to the asphalt content. Testing for recycled asphalt mixes is carried out with Marshall Test, Indirect Tensile Strength (ITS), and water absorption testing for recycled mixtures for paving blocks. The test results show the addition of NCR by the dry method has increased the strength of the mixture at both ambient and higher temperatures of 35 °C and 45 °C.
Fuzzy logic based life cycle cost analysis model for preventive road maintenance by considering user costs International Journal of Engineering Research and Technology, 2020
Laboratory investigation on skid resistance of hot mix asphalt pavement with nano crumb rubber contribution Sigit P.Hadiwardoyo, Oliver Senawibowo, R. Jachrizal Sumabrata, Dadang Iskandar Civil Engineering and Architecture, 2020 As the number of vehicles increases, the increasing number of used tires becomes an important issue, which needs to be handled so as not to become waste. One method that has been widely used is to process used tires into Crumb Rubber which in the field of road pavement can be utilized as added material. Hot mix asphalt concrete has a service life based on the mixture's mechanical strength, but its slip resistance is another important thing. The slip resistance is influenced by the composition of asphalt concrete aggregate as well as temperature. The increase of asphalt concrete mixture, whose content will experience an increase in temperature, will decrease the value of its slip resistance because asphalt becomes softer, which will result in a decrease in the bonding ability between asphalt and aggregate. Crumb Rubber is refined into Nano-sized particles in hot mix asphalt concrete. The percentages of Nano Crumb Rubber used in asphalt content are 0%, 2.5%, and 5% by using the dry process method. This skid resistance test is performed by using a British Pendulum Tester and carried out under various temperature conditions, 26 ℃, 30 ℃, 35 ℃, 40 ℃, and 45 ℃. Test results have shown that at normal temperature (25 ℃) asphalt modification is smaller than the asphalt mixture of virgin asphalt. However, at temperatures above 40 ℃ the opposite occurs, especially in the addition of 2.5%. The addition of Nano Crumb Rubber 2.5% has reduced the effect of high temperature more than 40 ℃ on the asphalt mixture.
On-site sanitation system and fecal contamination in shallow groundwater in urban Indonesia: assessing influence of distance and rainfall variables GL Putri, AM Ilmi, R Handayani, D Iskandar, CR Priadi, J Willetts, T Foster Water Research, 124431 , 2025 2025 Citations: 9
Pendampingan Lanjutan Optimalisasi Pendampingan Paving Block Berbahan Baku Limbah Plastik Tertolak (Plastik LDPE) Kelurahan Yosodadi, Kecamatan Metro Timur, Kota Metro ST Chica Oktavia, Y Amran, S Kurniawan, D Iskandar, L Sriharyani, ... SINAR SANG SURYA: Jurnal Pusat Pengabdian Kepada Masyarakat 9 (1), 95-107 , 2025 2025
PERILAKU LENTUR BALOK BETON BERTULANG DENGAN PERKUATAN PELAT BAJA STRIP BERBASIS RAL AP Sari, D Iskandar, C Oktavia JUMATISI: Jurnal Mahasiswa Teknik Sipil 5 (2), 405-409 , 2024 2024
Pelatihan Dan Pendampingan Pembuatan Paving Block Berbahan Baku Limbah Plastik HDPE Kelurahan Yosodadi, Kecamatan Metro Timur, Kota Metro D Iskandar, S Kurniawan, Y Amran, C Oktavia, L Sriharyani, E Prawati, ... SINAR SANG SURYA: Jurnal Pusat Pengabdian Kepada Masyarakat 8 (2), 187-199 , 2024 2024 Citations: 1
KAJIAN KUAT LEKAT SAMBUNGAN ANGKUR PADA BETON YANG DIPERKUAT BAHAN ADHESIVE (SIKA ANCHORFIX-2) D Iskandar, C Oktavia JUMATISI: Jurnal Mahasiswa Teknik Sipil 5 (1), 384-396 , 2024 2024
KEBEBASAN PRIBADI VS KONTROL NEGARA DALAM MENGGUNAKAN HAK PILIH SAAT PEMILIHAN UMUM L MEIREINI, DS ISKANDAR, MF SUDRAJAT, FD PUTRI VISIONER: JURNAL PEMERINTAHAN DAERAH DI INDONESIA Учредители: Goacademica … , 2024 2024
Improvement of buton rock asphalt performance by adding nano-crumb rubber and waste engine oil SP Hadiwardoyo, RJ Sumabrata, AC Nissa, FA Muhammad, M Hia, ... International Journal of Pavement Research and Technology 16 (5), 1181-1195 , 2023 2023 Citations: 24
PENGGUNAAN RECYCLE CONCRETE AGREGATE TERHADAP KUAT TEKAN BETON BERBASIS ANALYTICAL HIERARCHY PROCESS AS Rizki, D Iskandar, S Kurniawan JUMATISI: Jurnal Mahasiswa Teknik Sipil 4 (1), 272-278 , 2023 2023
Reuse of Construction Waste for Sustainable Development MN Dadang Iskandar, R. Jachrizal Sumabrata, Eri Prawati, Yusuf Amran Civil Engineering and Architecture 11 (5A), 2895-2903 , 2023 2023 Citations: 4
Scrutinizing the Effect of Water Temperature on the Compressive Strength of Recycled Concrete SK Dadang Iskandar, Ida Hadijah, Sigit P. Hadiwardoyo, Novia Lumintu Wati Civil Engineering and Architecture 11 (4), 1668 - 1678 , 2023 2023
Evaluation of the Sustainability Indicator for Road Infrastructure in Indonesia RJ Sumabrata, D Iskandar, R Abiyoga Civil Engineering and Architecture 10 (6), 2603-2615 , 2022 2022 Citations: 3
PEMANFAATAN KEMBALI SAMPAH KONSTRUKSI UNTUK PEMBANGUNAN YANG BERKELANJUTAN D Iskandar, E Prawati, I Hadijah PROSIDING SEMINAR NASIONAL PENELITIAN DAN PENGABDIAN KEPADA MASYARAKAT … , 2022 2022
Soft computing mix design beton berdasarkan SNI 7656: 2012 H Shabira, D Iskandar, S Kurniawan JUMATISI: Jurnal Mahasiswa Teknik Sipil 3 (1), 225-234 , 2022 2022 Citations: 2
DESAIN CAMPURAN BETON MUTU TINGGI BERBAHAN AGREGAT LOKAL MENGGUNAKAN ADMIXTURE BESTMITTEL TIPE-E (Design Of High Quality Concrete Mixed Material Local Aggregateusing Admixture … RH Lendrian, D Iskandar, SU Dewi JUMATISI: Jurnal Mahasiswa Teknik Sipil 3 (1), 219-224 , 2022 2022 Citations: 4
Soft Computing Penilaian Kondisi Perkerasan Jalan Berbasis Artificial Neural Networks D Iskandar, L Sriharyani TAPAK (Teknologi Aplikasi Konstruksi): Jurnal Program Studi Teknik Sipil 10 … , 2021 2021 Citations: 4
The development of readiness indicators for transit-oriented areas D Iskandar, RJ Sumabrata, R Abiyoga Civil Engineering and Architecture 9 (2), 453-461 , 2021 2021 Citations: 8
Pemeliharaan Jalan Berbasis Kinerja Perkerasan Menggunakan Metode Life Cycle Cost RA Haq, D Iskandar, I Hadijah JUMATISI: Jurnal Mahasiswa Teknik Sipil 1 (1), 62-73 , 2020 2020 Citations: 4
Contribution of Nano Crumb Rubber on Recycled Asphalt Concrete As Pedestrian Paving Block SL Annisa, SP Hadiwardoyo, RJ Sumabrata, D Iskandar IOP Conference Series: Materials Science and Engineering 811 (1), 012036 , 2020 2020 Citations: 1
Temperature Effect on the Deformation of the Recycled Hot-Mix Asphalt Concrete with Nano Crumb Rubber as an Added Material with Wheel Tracking Machine SP Hadiwardoyo, RH Aryapijati, RJ Sumabrata, D Iskandar IOP Conference Series: Materials Science and Engineering 811 (1), 012037 , 2020 2020 Citations: 4
Laboratory investigation on skid resistance of hot mix asphalt pavement with nano crumb rubber contribution SP Hadiwardoyo, O Senawibowo, RJ Sumabrata, D Iskandar Civ. Eng. Archit 8 (4), 662-668 , 2020 2020 Citations: 11
MOST CITED SCHOLAR PUBLICATIONS
Improvement of buton rock asphalt performance by adding nano-crumb rubber and waste engine oil SP Hadiwardoyo, RJ Sumabrata, AC Nissa, FA Muhammad, M Hia, ... International Journal of Pavement Research and Technology 16 (5), 1181-1195 , 2023 2023 Citations: 24
Laboratory investigation on skid resistance of hot mix asphalt pavement with nano crumb rubber contribution SP Hadiwardoyo, O Senawibowo, RJ Sumabrata, D Iskandar Civ. Eng. Archit 8 (4), 662-668 , 2020 2020 Citations: 11
On-site sanitation system and fecal contamination in shallow groundwater in urban Indonesia: assessing influence of distance and rainfall variables GL Putri, AM Ilmi, R Handayani, D Iskandar, CR Priadi, J Willetts, T Foster Water Research, 124431 , 2025 2025 Citations: 9
Road maintenance strategy with characteristic of drainage condition based on pavement performance D Iskandar, SP Hadiwardoyo, RJ Sumabrata, IN Fitriasari AIP Conference Proceedings 1977 (1), 040010 , 2018 2018 Citations: 9
The development of readiness indicators for transit-oriented areas D Iskandar, RJ Sumabrata, R Abiyoga Civil Engineering and Architecture 9 (2), 453-461 , 2021 2021 Citations: 8
Rut depth characteristics on hot mix asphalt with addition nano crumb rubber SP Hadiwardoyo, FNP Imansyah, RJ Sumabrata, D Iskandar Civil Engineering and Architecture 8 (4), 525-532 , 2020 2020 Citations: 7
Pengaruh Kondisi Drainase Terhadap Kerusakan Perkerasan Jalan Lentur dengan Metode Pavement Condition Index (PCI) V Novitasari, D Iskandar TAPAK (Teknologi Aplikasi Konstruksi): Jurnal Program Studi Teknik Sipil 7 … , 2017 2017 Citations: 6
Deformation of rutting due to temperature change from recycle of hot-mix asphalt with crumb rubber D Iskandar, S Pranowo Hadiwardoyo, R Jachrizal Sumabrata IOP Conference Series: Materials Science and Engineering 453 (1), 012015 , 2018 2018 Citations: 5
Reuse of Construction Waste for Sustainable Development MN Dadang Iskandar, R. Jachrizal Sumabrata, Eri Prawati, Yusuf Amran Civil Engineering and Architecture 11 (5A), 2895-2903 , 2023 2023 Citations: 4
DESAIN CAMPURAN BETON MUTU TINGGI BERBAHAN AGREGAT LOKAL MENGGUNAKAN ADMIXTURE BESTMITTEL TIPE-E (Design Of High Quality Concrete Mixed Material Local Aggregateusing Admixture … RH Lendrian, D Iskandar, SU Dewi JUMATISI: Jurnal Mahasiswa Teknik Sipil 3 (1), 219-224 , 2022 2022 Citations: 4
Soft Computing Penilaian Kondisi Perkerasan Jalan Berbasis Artificial Neural Networks D Iskandar, L Sriharyani TAPAK (Teknologi Aplikasi Konstruksi): Jurnal Program Studi Teknik Sipil 10 … , 2021 2021 Citations: 4
Pemeliharaan Jalan Berbasis Kinerja Perkerasan Menggunakan Metode Life Cycle Cost RA Haq, D Iskandar, I Hadijah JUMATISI: Jurnal Mahasiswa Teknik Sipil 1 (1), 62-73 , 2020 2020 Citations: 4
Temperature Effect on the Deformation of the Recycled Hot-Mix Asphalt Concrete with Nano Crumb Rubber as an Added Material with Wheel Tracking Machine SP Hadiwardoyo, RH Aryapijati, RJ Sumabrata, D Iskandar IOP Conference Series: Materials Science and Engineering 811 (1), 012037 , 2020 2020 Citations: 4
Evaluation of the Sustainability Indicator for Road Infrastructure in Indonesia RJ Sumabrata, D Iskandar, R Abiyoga Civil Engineering and Architecture 10 (6), 2603-2615 , 2022 2022 Citations: 3
Fuzzy logic based life cycle cost analysis model for preventive road maintenance by considering user costs D Iskandar, SP Hadiwardoyo, RJ Sumabrata International Journal of Engineering Research and Technology 13 (4), 725-733 , 2020 2020 Citations: 3
Investigation of the correlation between drainage condition and pavement performance D Iskandar, SP Hadiwardoyo, RJ Sumabrata, M Fricilia IOP Conference Series: Materials Science and Engineering 673 (1), 012115 , 2019 2019 Citations: 3
Soft computing mix design beton berdasarkan SNI 7656: 2012 H Shabira, D Iskandar, S Kurniawan JUMATISI: Jurnal Mahasiswa Teknik Sipil 3 (1), 225-234 , 2022 2022 Citations: 2
The use of reclaimed asphalt pavement by adding retona asbuton on asphalt concrete wearing course using the warm mix asphalt method RA Suyuti, RJ Sumabrata, SP Hadiwardoyo, D Iskandar AIP Conference Proceedings 2114 (1), 040002 , 2019 2019 Citations: 2
Overlay maintenance on road heavy vehicle lane by non-destructive test method D Iskandar, SP Hadiwardoyo, RJ Sumabrata, H Ariyapijati AIP Conference Proceedings 2114 (1), 030016 , 2019 2019 Citations: 2
ANALISIS PENGUJIAN GRADASI EKSTRASI (AC-BC) HASIL PRODUKSI AMP (ASPHALT MIXING PLANT) D Iskandar TAPAK (Teknologi Aplikasi Konstruksi): Jurnal Program Studi Teknik Sipil 3 (1) , 2016 2016 Citations: 2