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Civil Engineering Dimension
The Civil Engineering Dimension (CED) was first accredited by the Directorate General of Higher Education of Indonesia in 2000, with its decree No. 395/DIKTI/Kep/2000. Since then, CED has been honored with the accreditation status without any interruption. The latest accreditation decree is No. 80/DIKTI/Kep/2012, dated 13 December 2012, valid for 5 (five) years.
Articles
330
Articles
Metaheuristic-Based Machine Learning System for Prediction of Compressive Strength based on Concrete Mixture Properties and Early-Age Strength Test Results

Prayogo, Doddy

Civil Engineering Dimension Vol 20, No 1 (2018): MARCH 2018
Publisher : Institute of Research and Community Outreach - Petra Christian University

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Abstract

Estimating the accurate concrete strength has become a critical issue in civil engi­neer­ing. The 28-day concrete cylinder test results depict the concretes characteristic strength which was prepared and cast as part of the concrete work on the project. Waiting 28 days is important to guarantee the quality control of the procedure, even though it is a slow process. This research develops an advanced machine learning method to forecast the concrete compressive strength using the concrete mix proportion and early-age strength test results. Thirty-eight historical cases in total were used to create the intelligence prediction method. The results obtained indicate the effectiveness of the advanced hybrid machine learning strategy in forecasting the strength of the concrete with a comparatively high degree of accuracy calculated using 4 error indicators. As a result, the suggested study can provide a great advantage for construction project managers in decision-making procedures that depend on early strength results of the tests.

Wave Trajectory Study on the Coast of Lhoknga, Aceh Besar, Indonesia: A Numerical Model Approach

Setiawan, Ichsan, Irham, Mohammad

Civil Engineering Dimension Vol 20, No 1 (2018): MARCH 2018
Publisher : Institute of Research and Community Outreach - Petra Christian University

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Abstract

A numerical model of wave trajectory using shoaling and refraction formula was proposed in the coastal waters of Lhoknga, Aceh Besar, Indonesia. The developed model used a two dimensional (2D) numerical methods for wave trajectory with the input of wave height and period; 0.62 m and 8 second for high tide and 0.47 m and 6 second for low tide. This model was tested on site during low tide and high tide conditions for verification. The purpose of this numerical study is to trace the distribution of wave trajectory because of shoaling, wave breaking, and wave refraction. The model determines the wave height and crest pattern of the ray wave trajectory. The simulation result shows the pattern of the wave propagation at Lhoknga beach moves from the northwest to the east and south of the coast. The model also informs that the maximum wave height during high tide condition is 1.72 m and 1.31 m during low tide condition. The result indicates that the coast of Lhoknga has moderate wave conditions caused by a gentle beach bathymetry slope.

Performance of an Existing Reinforced Concrete Building Designed in Accordance to Older Indonesian Seismic Code: A Case Study for a Hotel in Kupang, Indonesia

Pudjisuryadi, Pamuda, Lumantarna, Benjamin, Setiawan, Ryan, Handoko, Christian

Civil Engineering Dimension Vol 20, No 1 (2018): MARCH 2018
Publisher : Institute of Research and Community Outreach - Petra Christian University

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Abstract

The recent seismic code SNI 1726-2012 is significantly different compared to the older code SNI 1726-2002. The seismic hazard map was significantly changed and the level of maximum considered earthquake was significantly increased. Therefore, buildings designed according to outdated code may not resist the higher demand required by newer code. In this study, seismic performance of Hotel X in Kupang, Indonesia which was designed based on SNI-1726-2002 is investigated. The structure was analyzed using Nonlinear Time History Analysis. The seismic load used was a spectrum consistent ground acceleration generated from El-Centro 18 May 1940 North-South component in accordance to SNI 1726-2012. The results show that Hotel X can resist maximum considered earthquake required by SNI 1726-2012. The maximum drift ratio is 0.81% which is lower than the limit set by FEMA 356-2000 (2%). Plastic hinge damage level is also lower than the allowance in ACMC 2001.

Evaluation of a Reinforced Concrete Wall Macroscopic Model for Coupled Nonlinear Shear-Flexure Interaction Response

Purnomo, Joko, Chandra, Jimmy

Civil Engineering Dimension Vol 20, No 1 (2018): MARCH 2018
Publisher : Institute of Research and Community Outreach - Petra Christian University

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Abstract

Reinforced concrete shear wall (RC wall) is an important element in tall buildings, which provides strength and stiffness against lateral loadings, e.g. earthquake and wind. Numerous researches have been conducted to study its nonlinear behavior via microscopic and macroscopic model. The later approach is currently being widely explored since it has many advantages compared to the preceding models. A well-known macroscopic model, namely Shear-Flexure-Interaction Multiple-Vertical-Line-Elements-Model (SFI-MVLEM) in the open source platform Open Sees, is capable of simulating the coupled nonlinear shear-flexure interaction response in the RC wall. This paper presents an evaluation to the applicability of SFI-MVLEM model to predict the coupled nonlinear shear-flexure behavior of RC wall specimens compared to experimental results in available literature. The analysis results show that the model is able to predict the behavior of RC wall considerably accurate in terms of hysteretic curves, cracking patterns, and contributions of shear and flexural displacement to total displacement.

Development of the DKMQ Element for Analysis of Composite Laminated Folded Plate Structures

Wong, Foek Tjong, Widjaja, Kristofer

Civil Engineering Dimension Vol 20, No 1 (2018): MARCH 2018
Publisher : Institute of Research and Community Outreach - Petra Christian University

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Abstract

The discrete-Kirchhoff Mindlin quadrilateral (DKMQ) element has recently been developed for analysis of composite laminated plates. This paper presents further development of the DKMQ for analysis of composite laminated folded plates. In this development, a local coordinate system is set up for each element at its centroid. The DKMQ stiffness matrix is superimposed with that of the standard four-node plane stress quadrilateral element to obtain a 24-by-24 folded plate stiffness matrix in the local coordinate system. To avoid singularity of the stiffness matrix, a small stiffness coefficient is added in the entries corresponding to the drilling degrees of freedom. The local stiffness matrix and force vector are then transformed to the global ones and assembled. The accuracy and convergence of the folded plate element are assessed using a number of numerical examples. The results show that the element is accurate and converge well to the reference solutions.

Stabilising Potential of Sawdust Lignin based Extracts in Compressed Lateritic Bricks

O.A, Fadele,, O.J., Ata,

Civil Engineering Dimension Vol 20, No 1 (2018): MARCH 2018
Publisher : Institute of Research and Community Outreach - Petra Christian University

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Abstract

Lignocellulosic materials are abundant in nature, rich in some functional groups, considered less harmful to human health and the environment.The resulting waste may be recycled for other beneficial uses. Lignin is known to be a natural binder in lignocellulosic materials and several studies have confirmed it has binding ability with soil particles. This paper studied its stabilising potential in compressed lateritic bricks, especially its effects on density and compressive strength properties of the bricks. Lignin additives extracted from sawdust were used to stabilise laterite, while the bricks were moulded with the UNIFE ram, a type of the CINVA ram. The laterite was stabilised at 4%, 8% and 12%, while cement stabilised samples and 0% (unstabilised laterite) samples prepared accordingly were used as controls. The results showed that the LBAs contributed to the strength gained by the bricks at 3, 7, 14 and 28 days air curing, while the bricks samples were categorised as high density.

A Numerical Investigation on the Structural Behavior of Deficient Steel Frames Strengthened using CFRP Composite

Keykha, Amir Hamzah

Civil Engineering Dimension Vol 20, No 1 (2018): MARCH 2018
Publisher : Institute of Research and Community Outreach - Petra Christian University

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Abstract

Carbon fiber reinforced polymers (CFRP) is one of the materials that is used to strengthen steel structures. Most studies on CFRP strengthening steel on structures have been done on beams and steel columns. No independent study has studied the effect of CFRP strengthening on the structural behavior of steel frames having initial deficiency.The deficiency in steel structures may be created due to the errors caused by construction and others.This study aims to carry out a numerical study on the efficiency of CFRP sheet on strengthening square hollow section (SHS) steel frames having initial deficiency. Seven specimens, five of which were strengthened using CFRP sheets, were analyzed. ANSYS software was used to analyze the SHS steel frames. The results showed that the coverage length, the width, and the number of CFRP layers have a significant effect on increasing and recovering the ultimate load capacity of the SHS steel frames having initial deficiency.

Spinning Induced Compression Strength of Precast Hollow Concrete Piles

Budi, Gogot Setyo, P.K., Suseno, S.K., Winata

Civil Engineering Dimension Vol 19, No 2 (2017): SEPTEMBER 2017
Publisher : Institute of Research and Community Outreach - Petra Christian University

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Abstract

Prefabricated precast-hollow concrete pile is widely used as deep foundations due to its several benefits such as the uniformity in concrete quality and its durability. It is also called spun pile since the spinning method is utilized to compact the fresh concrete. During spinning, the fresh concrete is propelled outward due to centrifugal force, which generates a compaction process and develops a hollow in the center of the pile. Several factors, such as the rate of spinning, frequency, and duration of spinning, are affecting the quality of the pile. This paper presents the study of density and compressive strength of spun piles. The specimens were cored from the spun piles with diameter of 800 mm. The results show that the density and the compressive strength of the concrete at outer region of the spun pile are bigger than those at the inner side.

Managerial Skills for Managing Construction Safety

Sunindijo, Riza Yosia, Zou, Patrick X.W., Dainty, Andrew

Civil Engineering Dimension Vol 19, No 2 (2017): SEPTEMBER 2017
Publisher : Institute of Research and Community Outreach - Petra Christian University

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Abstract

Previous research has suggested that self-awareness, visioning, and sincerity are foundational managerial skills for delivering positive safety outcomes in construction projects. This paper aims to verify this finding and to suggest learning approaches for developing these skills in practice. Interviews with experienced construction practitioners were analysed thematically to find common themes. The thematic analysis confirms the necessity of the mana­gerial skills identified in the previous research for managing construction safety and provides directions for construction organisations to improve safety learning. Existing approaches, which mainly adopt the cognitivism learning philosophy, may not be sufficient because the nature of learning in practice aligns with social constructivism, showing that learning occurs informally through interactions with people and artefacts at work instead of in a classroom-structured environment. Furthermore, although learning methods to develop safety skills have been suggested, there remains a need for better statistical evidence of the effectiveness of these methods in delivering safety outcomes.

Compressive Strength of Post Fire Exposed Concrete Column Wrapped with Fiber Reinforced Polymer

Wardaya, Dwi Agus Setiawan, Sugiharto, Handoko, Pudjisuryadi, Pamuda

Civil Engineering Dimension Vol 19, No 2 (2017): SEPTEMBER 2017
Publisher : Institute of Research and Community Outreach - Petra Christian University

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Abstract

In this study, behaviour of reinforced concrete columns strengthened using fiber reinforced polymer (FRP; glass fiber and carbon fiber) after fire exposure are discussed. After being exposed to fire as high as 720oC for 180 minutes, the specimens showed concrete and  reinforcement strength degradation, even though there was no carbonation. It was found that specimens wrapped by carbon fiber showed better compressive strength but less ductility compared to specimens wrapped by glass fiber. It was also found that the low initial compressive strength did not decrease FRP confinement effectiveness. Increase of wrapped concrete com­pressive strength was evident despite the low initial strength (<17 MPa). Strength esti­mation using ACI 440.2R-08 formula, which is originally for wrapped plain concrete without fire heat exposure, underestimated the compressive strength. In the proposed formula, the initial compressive strength (f’co) should be adjusted by considering the modulus elasticity and strain limitation to have more precise estimation.