cover
Contact Name
Agata Iwan Candra
Contact Email
iwan_candra@unik-kediri.ac.id
Phone
+62811308010
Journal Mail Official
ukarst@unik-kediri.ac.id
Editorial Address
Jl. Selomangleng no. 1
Location
Kota kediri,
Jawa timur
INDONESIA
U Karst
Published by Universitas Kadiri
ISSN : 25794620     EISSN : 25810855     DOI : http://dx.doi.org/10.30737/ukarst
Core Subject : Engineering,
U KaRsT is a journal of the civil engineering research the University of Kadiri published twice a year in April and November. First published in April 2017. U KaRsT already has both ISSN printed and online, for ISSN (Print) is 2579-4620, and ISSN (Online) is 2581-0855.
Arjuna Subject : -
Articles 6 Documents
Search results for , issue "Vol. 8 No. 1 (2024): APRIL" : 6 Documents clear
Abrams’ Law Formulation for Blended Cement Paste Incorporated with Ground Ferronickel Slag Djayaprabha, Herry Suryadi; Fatharani, Ashila Hasya
UKaRsT Vol. 8 No. 1 (2024): APRIL
Publisher : Kadiri University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30737/ukarst.v8i1.5485

Abstract

Ground ferronickel slag (GFS) is a form of an industrial waste by-product generated during the smelting process of nickel ore that has been crushed and ground into fine powder. GFS is a pozzolanic substance that may be employed as an environmentally beneficial binding agent when blended with Portland cement. This research aims to apply the Abrams Law formulation to blended cement combined with GFS. GFS was utilized as a Portland cement composite (PCC) replacement at varying percentages of 0, 10, 20, 30, 40, and 50 wt.%. The blended cement paste incorporated with GFS was tested at three water to cementitious material ratio (w/cm) levels of 0.4, 0.5, and 0.6. After samples have been made, a compressive strength test is carried out. The research results showed that at 28 days, the optimum amount of GFS was found in the percentage of 20 wt.% induced the compressive strength by 40.41 MPa with a w/cm of 0.4. The equations based on Abrams’ Law have been proposed for estimating the correlation of 28-day compressive strength with w/cm in the range from 0.4 to 0.6. In addition, the hardened densities of binary blended cement paste were investigated. It was found that the density decreased with an increase of w/cm. The proposed equations provide the beneficial interpretation for estimating the compressive strength of blended cement paste based on the w/cm..
Comparison of Predictive Modeling Concrete Compressive Strength with Machine Learning Approaches Airlangga, Gregorius
UKaRsT Vol. 8 No. 1 (2024): APRIL
Publisher : Kadiri University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30737/ukarst.v8i1.5532

Abstract

Accurately predicting concrete compressive strength is fundamental for optimizing mix designs, ensuring structural integrity, and advancing sustainable construction practices. Increased demands for safer, more durable infrastructure necessitate effective predictive concrete compressive strength models. This research aims to compare the effectiveness of six machine learning models such as Linear Regression, Random Forest, Support Vector Regression (SVR), K-Nearest Neighbors (KNN), Gradient Boosting, and XGBoost to predict concrete compressive strength. Used a dataset of 1030 instances with varying mixture compositions, conducted extensive exploratory data analysis, and applied feature engineering and data scaling to enhance model performance. Assessments were performed with a 5-fold cross-validation approach with the R-squared (R²) metric. In addition, the SHAP value is used to understand the influence of each feature on the compressive strength results. The results revealed that XGBoost significantly outperformed other models, achieving an average R² value of 0.9178 with a standard deviation of 0.0296. Notably, Random Forest and Gradient Boosting also demonstrated robust capabilities. Based on our experiment, these models effectively predicted compressive strengths close to actual measured values, confirming their practical applicability in civil engineering. SHAP values provided insights into the significant impact of age and cement quantity on model outputs. These results highlight the advanced ensemble methods' effectiveness in concrete compressive strength prediction and underscore the importance of feature engineering in enhancing model accuracy.
Simulation-Based Exploration with Energyplus as an Energy Efficiency Strategy Madani, Raihan; Winahyo, Antelas Eka
UKaRsT Vol. 8 No. 1 (2024): APRIL
Publisher : Kadiri University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30737/ukarst.v8i1.5534

Abstract

In countries with tropical or subtropical climates, such as Indonesia, the use of air conditioning is becoming increasingly important for comfort and productivity. However, high energy use in air conditioning systems has significant environmental and economic impacts, including increased greenhouse gas emissions and high operational costs. This research aims to analyze the Energy Consumption Index (ECI) in the Joint Lecture Building, State University of Malang using EnergyPlus software simulation. Research data consists of building data, weather data, building construction data, operating schedules, equipment specifications, and energy usage data. Furthermore, the data analysis technique used ECI calculations based on EnergyPlus software simulation. The research results show that based on the Energy Consumption Index value it is 201,943 kWh/m2/year, but with a savings scenario it becomes 161,964 kWh/m2/year (an increase of 19,797%) so it is classified as efficient. The energy-saving scenario implemented is to replace the Constant Air Volume (CAV) air conditioning system with Variable Air Volume (VAV) and the types of luminaires that were originally fluorescent will be replaced with Light Emitting Diodes (LEDs). The comparison results obtained an energy-saving value of 19,797%. The research results show that using VAV and LEDs technology can increase energy efficiency in the Joint Lecture Building, State University of Malang. The scenario attempts to reduce environmental impact through energy efficiency in commercial buildings and shows that the EnergyPlus simulation method is an effective approach for designing energy savings strategies.
Increasing Unconfined Compressive Strength of Soft Clay Stabilized with Coir Fiber and Bagasse Ash Mix Widianti, Anita; Sundi, Svastika Ariana; Rahmawati, Anita; Wibowo, Dian Eksana
UKaRsT Vol. 8 No. 1 (2024): APRIL
Publisher : Kadiri University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30737/ukarst.v8i1.5548

Abstract

Increasing coir fiber and bagasse ash waste can cause environmental degradation. Utilization of this waste in construction work is still rarely done. Coir fiber is a natural material with the highest coefficient of friction and tensile strength. Bagasse ash has a high silica content and is suitable for use as pozzolan. Soil stabilization with a combination of both is expected to improve the geotechnical properties of soft soil. This research aims to analyze the unconfined compressive strength (UCS) and secant modulus of soft clay stabilized with coir fiber-bagasse ash mix. Coir fiber as much as 0.75% and ash with varying contents: 0%, 2%, 4%, 6%, 8%, and 10% of the total weight of the mixture. The specimens were cured for 28 days. UCS tests were conducted according to ASTM D2166-16 with the axial stress and strain relationship curve results to determine the UCS and secant modulus. The results showed that the UCS value and secant modulus value increased along with increasing bagasse ash content. The maximum value was achieved at 8% ash variation with a UCS value of 472.45 kPa (an increase of 382% from a soil-coir fiber mix) and a secant modulus value of 21.94 MPa (an increase of 571% from a mixture of soil and coir fiber). The research results show that this mixed soil is classified as hard soil, which can withstand high loads. It is hoped that the results of this research can become a reference for stabilizing soft soil in the field.
Unveiling Subsurface Characteristics of Cliff Land in Sibang, Bali Through Geoelectric Investigation Diana, Nur Ayu; Mareta, Ganeca Efa
UKaRsT Vol. 8 No. 1 (2024): APRIL
Publisher : Kadiri University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30737/ukarst.v8i1.5557

Abstract

The unique geological formations and environmental dynamics of cliffs underscore the significance of comprehending soil composition and structural integrity for diverse applications, such as infrastructure development and environmental conservation. Geoelectrical needs to be done because the underground geological conditions of the cliff must be researched and assessed first before construction is carried out so that construction failure does not occur. This research aims to reveal the subsurface characteristics of cliff soil in Sibang, Bali through geoelectrical investigation. This research was conducted by evaluating the soil condition in the field using the geoelectric resistivity method to the ability of a material to inhibit the flow of electric current and geological regional theories. At points BL-01 and BL-04, there is a significant potential risk of landslides due to the thick layer of breccia, especially during high rainfall or additional loads in the area. Point BL-02 also has a potential risk of landslides due to the thick layer of basalt and wet sand. Meanwhile, points BL-03 and BL-05 are more ideal locations for construction because they consist of relatively stable hard rock. Point BL-06 outside the development zone has layers of gravel, weathered tuffa and andesite which could be considered for future development. Thus, a deep understanding of the geological characteristics of each point is important to manage risks and ensure the safety and sustainability of construction projects in that area.
Increasing Compressive Strength of Self Compacting Concrete with MasterGlenium and MasterSure Sefiyanti, Redyka; Mahardana, Zendy Bima; Rahmawati, Apriliya Laily; Husna, Nadiya; Zakiya, Zaizafun; Naufalanto, Hafiizh; Yuantono, Tegar Bhakti
UKaRsT Vol. 8 No. 1 (2024): APRIL
Publisher : Kadiri University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30737/ukarst.v8i1.5565

Abstract

The growth in development complexity demands innovation in the construction industry. Self-compacting concrete (SCC) can flow and fill mold cavities without additional vibration, offering an efficient solution for structures with complex shapes or tight spaces. In addition, SCC can speed up bonding and simplify workability by adding MasterGlenium and MasterSure superplasticizers. However, its use is limited due to a lack of understanding of the optimal composition of the mixture. The research aims to determine the effect of adding MasterGlenium and Maste Sure in the concrete mixture on the compressive strength of concrete. Experimental research was conducted with a mixture of MasterGlenium additives at 0.25%, 0,30%, 0,35%, 0.40%, and MasterSure 0.30% of the total binder. Slump and compressive strength tests of concrete are carried out to determine workability and quality performance. The research results showed that the optimal concrete mix with the addition of MasterGlenium 0.35% and MasterSure 0.30% was 25.39 Mpa, higher than Normal concrete 15.21 Mpa. The slump test results confirm that the concrete is classified as SCC. This shows the importance of the composition of MasterGlenium and MasterSure superplasticizers on the compressive strength of SCC concrete. So, the results of this research can be used to improve the quality of concrete structure projects.

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