Comparative Analysis of Concrete and Steel Column Work Assessed from Cost and Time in Heavy Equipment
Warehouse Development Project Cileungsi, Kab. Bogor
Novika Candra Fertilia , Aditya Zaki Septiawan
Faculty of Engineering, Mercu Buana University Jakarta, Indonesia [email protected], [email protected].
[email protected] Abstract
PT. Waskita Karya Infra 2 Division will now add workshops located in the city of Cileungsi, Bogor regency. It is hoped that the workshop will be able to meet the needs of maintenance and storage facilities for heavy equipment for ongoing infrastructure projects. Therefore, because of the differences in material for heavy equipment warehouse 1 and heavy equipment warehouse 2, the authors are interested in conducting research to find out the amount of costs and time spent on heavy equipment warehouse 1 and heavy equipment 2 column work, in this study using quantitative analysis methods accompanied by journal literature or previous research related to this research. the results of the author's analysis in this study the cost of concrete column heavy equipment warehouse 1 is Rp. 216,372,808 while the cost of steel columns in Heavy Equipment Warehouse 2 is Rp. 282,911,957 then the difference in costs is Rp. 66,539,148, from the results of this study that concrete columns are cheaper than steel columns, for the results of the analysis of work time on concrete columns for Heavy Equipment Warehouse 1 takes 20 days while steel column work time at Heavy Equipment Warehouse 2 takes 12 days, then the time difference that occurs is for 8 days, which means that the steel column works faster.
Keywords:
Cost, Concrete Column, Steel Column, Time
1. Introduction
PT. Waskita Karya Infra 2 Division will now add workshops located in the city of Cileungsi, Bogor regency. It is hoped that the workshop will be able to meet the needs of maintenance and storage facilities for heavy equipment for ongoing infrastructure projects. In this workshop, there are several buildings including a heavy equipment workshop and warehouse, and a heavy equipment parking area. Workshop facilities will later be used for the maintenance of heavy equipment owned by PT. Waskita Karya, Infra 2 Division, and heavy equipment warehouse will function to store heavy equipment spare parts material.
Figure 1. A view of the Workshop Site Plan
Therefore, because of the difference in material for heavy equipment warehouse 1 and heavy equipment warehouse 2, the authors are interested in conducting research to find out the amount of costs and time spent on heavy equipment warehouse 1 and heavy equipment warehouse 2 column work, and the author will also compare the difference between the cost and time of column work in heavy equipment warehouse 1 and heavy equipment warehouse 2. In order to ascertain which column requires more cost and which column has a faster work time.
1.1. Identification Of Problems
Based on the background described above, the drawing design of heavy equipment warehouse 1 and heavy equipment warehouse 2 has the same building area, namely 864 m2 or a building length of 36 m and a building width of 24 m with the same number of column points 25 column points, but there are differences in material in the column structure, the heavy equipment warehouse column structure 1 uses concrete material with Fc '25 mpa quality and in the heavy equipment warehouse 2 column uses WF 250 x 125 x 6 x 9 steel, with this difference in material, the authors propose research by identifying the comparison of concrete and steel columns in terms of costs and time of work to find out which column costs are more expensive or cheaper and to find out which column work is faster or longer
1.2. Scope of Problem
In the writing of this Final Project, it is limited by several problem limitations, in order to provide better analysis results. The limitations of the problem include:
h. Budget for concrete column and steel column work based on the project drawing design plan.
i. The price coefficient for the concrete work unit used is (SNI 7394:2008, 2008) j. The steel work unit price coefficient used is (SNI 7393 2008, 2008)
k. Unit prices for materials and wages use the Journal of Unit Prices for Construction and Interior Building Materials Edition 39 of 2020
l. Time of execution of concrete column and steel column work based on direct field observations
m. The research was conducted from the perspective of the owner / owner and contractor because in this heavy equipment warehouse project the owner / owner also acts as a contractor.
2. Research Methodology
In writing this thesis, the author uses quantitative analysis methods accompanied by journal literature or previous research related to this research. The raw data obtained from various sources is then tabulated into data that can be used as material for analysis regarding costs and time in the process of working on concrete columns and steel columns in the project under study.
Figure 2. Research Flowchart 2.1. Research Explanation
1. Background The initial step of the research was started by observing the work of concrete and steel columns.
2. Problem formulation Problem formulation that compares concrete and steel columns is best in terms of cost and time.
3. Preparation Phase The preparatory stage includes literature study of the discussion material and collecting literature from various sources.
4. Data Collection At this stage, data collection will be carried out for the implementation needed during the research process. Based on the source, research data can be grouped into two types, namely primary data and secondary data.
5. Time analysis The time analysis method used is the result of field observations. Then in the scheduling process using a bar chart, it is processed using Microsoft Project Software.
Start
Background
Formulation of the problem
Preparation Phase
Data Collection Primary
Secondary
Data analysis :
1. Concrete column work 2. Steel column work
Cost Analysis Using : Job Time Analysis :
Comparative Analysis Of Cost And Time Column Work
Research Result
Conclusion
Done
1. SNI 7394:2008 Concrete 2. SNI 7393:2008 Steel
3. Journal of Unit Price of Materials and Wages 39th edition of 2020
1. Project Location Observations 2. Bar Chart Time Schedule
6. Cost Analysis For cost analysis using the calculation method of unit price analysis. The concrete column uses the coefficient of labor and materials which refers to (SNI 7394:2008, 2008) while the steel column uses the coefficient of labor and materials refers to (SNI 7393 2008, 2008) .The price of material and wages for labor uses the standard price in West Java. The results of the unit price analysis are summarized into one in the form of a Budget Plan (RAB).
7. Conclusions and Suggestions After collecting and processing data, it can be concluded that the final results will be summarized in a study. Suggestions are in the form of comments and rebuttals that are suggestive either to related agencies or other prospective researchers.
Table.1 explains that the costs compared are 3 components, namely comparing the labor, materials, and equipment used from each work item.
Table 1. Compared Cost Components Heavy Equipment Warehouse Concrete
Colum 1
Heavy Equipment Warehouse Concrete Colum 2
Profession Unit Volume Profession Unit Volume
Steel bar Kg 3207,24 Stell Wf 250.125.6.9 Kg 4162,66
Concrete Fc’25
Mpa M3 17,47 Anchor Dia 16 mm Bh
112,00
Formwork M2 203,84 End Plate Kg 633.024
Painting M2 203,84 Plat Rib Kg 9495,36
Grounting M3 0,168
Painting M2 109,2
Equipment Rental Unit Volume Equipment Rental Unit Volume
Concrete Pump
Rental Unit 1 Rental Mobil crane Unit
2
Rent scaffolding Unit 1 Welding Machine Unit 3
Rent a Concrete Vabiator
Unit 2
Table.2explains that doing a time analysis on concrete column and steel column work. The results of the analysis will later be compared to find out the time difference that occurs in concrete and steel column work.
Table 2. Time Components Compared Job Duration
C O M P A R I S O N
Job Duration
Concrete Colum Work Pekerjaan Kolom baja WF
Reinforcing Steel Fabrication WF 250,125.6.9
ReadymuxFc ’25 Mpa Concrete Steel eretion WF 250,125.6.9
Use 3xFormwork Anchor dia. 16mm
Instalation Endplate
Demolition Plat Rib
Concrete Curing Grouting
Painting Painting
Amount Amount
3. Data Annalysis
The object of this study, the authors conducted a comparative study of concrete columns in heavy equipment warehouse 1 with steel columns in heavy equipment warehouse 2 in terms of cost and time. The object under study is concrete column work in heavy equipment warehouse 1 and steel column work in heavy equipment warehouse 2. The research carried out includes concrete column work and steel column work.
Research is limited from the beginning of the column work to the paint finishing job.
3.1. Recapitulation of Work Volume
In Table.3 it can be seen that the recapitulation of the volume of concrete column work in heavy equipment warehouse 1 and a recapitulation of the volume of steel column work at heavy equipment warehouse 2, the volume will later be used as a reference in calculating the work costs for each work item
Table 3. Recapitulation of Work Volume to be Compared Heavy Equidment Warehouse 1
C O M P A R I O N
Heavy equipment WareHouse 2 No Concrete
Column Work
Unit Price Total Price No Pekerjaan Kolom Baja WF
Harga Satuan Total Harga A Preparenting
Work
A Preparenting Work
1 Electrical Work Rp9.900.000 Rp9.900.000 1 Electrical Work Rp5.940.000 Rp5.940.000 2 Working Water Rp5.500.000 Rp5.500.000 2 Working Water Rp3.300.000 Rp3.300.000
3 Project
admistrastation
&
Documentation
Rp4.400.000 Rp4.400.000 3 Project
admistrastation
&
Documentation
Rp2.640.000 Rp2.640.000
4 ShopDrawing &
As Built Drawing
Rp6.600.000 Rp6.600.000 4 ShopDrawing &
As Built Drawing
Rp3980.000 Rp3980.000 5 Quality Control Rp13.200.000 Rp13.200.000 5 Quality Control Rp7920.000 Rp7.920.000 B 400 X 300
Concrete Column Work
B Steel Column Work WF 250.125.6.9 1 Reinforaing Rp24.751 Rp79.383.316 1 Steel Fabrication
WF 250.125.6.9
Rp 12.146 Rp50,559.479 2 Reachymic Fc ‘
25 Mpa Concrete
Rp1.613.370 Rp28.166.792 2 Steel Erection WF 250.125.6.9
Rp 37.850 Rp80.003.828
3 Use 3X
Formwork
3 Anchor dia 16mm
Rp 412.710 Rp2.367.814 Installain Rp 35.3690 Rp24.032.052 4 End Late Rp 57.358 Rp13.382.888
Demalilian Rp 11.667 Rp2.382.206 5 Plast Rib Rp 57.366 Rp2.007.433
4 Concrete Quring Rp13.848 Rp2.822.723 6 Grounting Rp14.327.500 Rp2.407.020
5 Painting Rp 63.567 Rp12.961.539 7 Painting
C Equipment Rental
C Equidment Rental 1 Rent Concrete
Vibrator
Rp770.000 Rp3.850.000 1 Welding
machire
Rp450.000 Rp13.500.000 2 Rent Scalfolding Rp3.394.274 Rp16.971.370 2 Rental Mobile
Crane
Rp4.094.274 Rp82.485.460 3 Concrete Pump
Rental
Rp309.040 Rp6.180.809
Total Work Price Rp216.372.606 Total Work Price Rp282.911.363
Rounded Off Rp216.372.808 Rounded Off Rp282.911.957
3.2. Concrete Column Work Unit Price Analysis
Analysis of the unit price of the ironwork on the concrete column, the author refers to Table.4, in the table it is explained that the unit price of the iron work per 10 kg is Rp. 225,012, and to calculate the ironwork per kilogram is Rp. 247,510 / 10 Kg = Rp. 24,751 per kilogram.
Table 4. Price Per Kilogram of Construction Work
No Description Unit Coeficient Unit Price Total Price
Main Power
Workers OH 0,070 Rp 157.643 Rp 11.035
Black Mith OH 0,070 Rp 166.729 Rp 11.671
Foremen OH 0,007 Rp 182.676 Rp 1.279
Foremen OH 0,004 Rp 194.274 Rp 777
Material
Concrete Iron (Plain / Threaded) Kg Rp 18.700 Rp 196.350
Concrete Wire Kg Rp 26.000 Rp 3.900
Equipment
Total Price
Total Unit Price Of Iron Work Per 1Kg
Rp 225.012 Rp 22.501 Overhead & Profit 10%
Total Price
Rp 2.250 Rp 24.751 3.3. Unit Price Analysis for Steel Columns
Analysis of the unit price of steel erection work on steel columns, the author refers to Table.5, in the table it is explained that the unit price of steel work per 1 kg is Rp. 37,850
Table 5. Price Per Kilogram of Steel Erection Work
No Description Unit Coeficient Unit Price Total Price
Main Power
Workers OH 0,060 Rp 157.643 Rp 9.459
Construction Welder OH 0,060 Rp 166.729 Rp 10.004
Foremen OH 0,006 Rp 182.676 Rp 1.098
Foremen OH 0,003 Rp 194.274 Rp 583
Material
Steel WF 250.125.6.9 Kg Rp 9.755 Rp 11.218
Welding Wire Kg Rp 41.000 Rp 2.050
Equipment
Total Price Overhead & Profit 10%
Rp 34.410 Rp 3.441
Total Price Rp 37.850
3.4. Analysis of the Budget Plan for Concrete Columns
In Table.6 it can be explained to calculate the amount of cost for each concrete column work item by multiplying the volume of the work item with the unit price of work or (volume x unit price = work item cost).
Example: the volume of ironwork is 3207.24 kg multiplied by the unit price of Rp. 22,501 the result was Rp.
79,383,318 or (3207.24 Kg x Rp. 24,751 = Rp. 79,383,318). From the results of the amount of costs for each work item then added up to find out the total cost of the concrete column work. In this research, after calculating the amount of costs on the concrete column of Rp. 216,372,808 as in (Table 6).
Table 6. Concrete Column Cost Budget Plan No Description Unit Volume
Unit Price of Material
Unit Price Of Wage 8
Equipment Rental Unit
Price
Unik Price (overhead % Profit 10% )
Total Price A Prepatory Work
1 Electical Water Ls 1 Rp9.900.000 Rp9.900.000
2 Working Water Ls 1 Rp5.500.000 Rp5.500.000
3 Project
Administration
&
Documentation
Ls 1
Rp4.400.000 Rp4.400.000 4 ShopDrawing &
As Built Drawing
Ls 1
Rp6.600.000 Rp6.600.000
5 Quality Control Ls 1 Rp13.200.000 Rp13.200.000
B 400 X 300 Concrete Column Work
1 Reinforaing Kg 3.207,24 Rp20.025 Rp 2.476 Rp 24.751 Rp 79.363.318
2 Reachymic Fc ‘ 25 Mpa Concrete
M3 17,47 Rp
1.243.380
Rp 222.320 Rp 1.613.370 Rp 28.188.792
3 Use 3X
Formwork
- Installain M2 203,84 Rp
150.002
Rp171.504 Rp 353.690 Rp 24.032.052
- Demalilian M2 203,84 Rp 10.624 Rp 11.687 Rp 2.382.206
4 Concrete Quring M2 203,84 Rp 15.002 Rp 133.885 Rp 13.848 Rp 2.822.723
5 Painting M2 203,84 Rp14.040 Rp 43.766 Rp 63.587 Rp 12.961.539
C Equipment Reantal 1 Rent Concrete
Vibrator
Unit 2.00 Rp 700.00 Rp 770.000 Rp 3.850.000
2 Rent Scalfolding Unit 1,00 Rp 309.040 Rp 309.000 Rp 6.180.809
3 Concrete Pump Rental
Unit 1,00 Rp 194.274 Rp
3.200.000
Rp 3.394.274 Rp 16.971.370
Total Work Price Rp
216.372.808
Rounded off Rp
216.372.808 3.5. Analysis of the Steel Column Budget Plan
In Table.7 it can be explained to calculate the cost of each steel column work item by multiplying the volume of the work item with the unit price of the work or (volume x unit price = work item cost). Example: the volume of WF 250.125.6.9 steel work is 4162.66 Kg multiplied by the unit price of WF 250.125.6.9 steel erection work of Rp. 34,410 results were obtained for Rp. 88,003,626 or (4162.66 Kg x Rp. 34,410 = Rp.
88,003,626). From the results of the amount of costs for each work item then added up to find out the total cost of the steel column
work. In this research, after calculating the amount of cost on the steel column of Rp. 282,911,957 as in Table.7
Table 7. Concrete Column Cost Budget Plan No Description Unit Volume Unit Price
of Material
Unit Price Of Wage 8
Equipment Rental Unit
Price
Unik Price (overhead % Profit 10% )
Total Price A Prepatory Work
1 Electical Water Ls Rp 5.940.000 Rp 5.940.000
2 Working Water Ls Rp 3.300.000 Rp 3.300.000
3 Project
Administration
&
Documentation Ls
Rp 2.640.000 Rp2.640.000 4 ShopDrawing &
As Built Drawing
Ls
Rp 3.690.000 Rp 3.690.000
5 Quality Control Ls Rp 7.920.000 Rp 7.920.000
B Steel Column Work WF 250.125.6.9 1 Steel Fabrication
Work WF 250.125.6.9
Kg 4162,66 Rp 11.042 Rp 12.146 Rp 50.559.479
2 Steel Erection Work WF 250.125.6.9
Kg 4162,66 Rp 13.268 Rp 21.141 Rp 37.850 Rp 88.003.626
3 Anchor dia. 16 mm
Bh 112,00 Rp 354.050 Rp 21.141 Rp 412.710 Rp 2.367.814
4 Endplate Kg 633,02 Rp 31.030 Rp 21.141 Rp 57.338 Rp 13.382.886
5 PlatRib Kg 94,95 Rp 31.030 Rp 21.141 Rp 57.338 Rp 2.007.433
6 Grouting M3 0,17 Rp
13.025.000
- Rp 14.327.500 Rp 2.407.020
7 Painting M2 109,20 Rp 6.240 Rp 40.638 Rp 51.566 Rp 4.437.655
C Equipment Reantal
- Welding
Machine
Unit 3,00 Rp 450.000 Rp 450.000 Rp 13.500.000
- Rental Mobile Crane
Unit 2,00 Rp
194.274
Rp 3.900.000
Rp 4.094.274 Rp 82.485.480
Total Work Price Rp
282.911.393
Rounded off Rp
282.911.957 3.6. Duration of Concrete Column Work Time
Based on field observations, the steps for concrete column work for heavy equipment warehouse 1 are in accordance with Figure.3, starting from the ironwork and fabrication of column formwork according to the column dimensions, in 1 day the worker is able to produce 6 columns while fabricating 6 column formwork takes time. for 2 days, then the 6 ready-made columns are installed formwork that has been fabricated, after the formwork has been installed, the next step is casting work with the quality of the concrete in the drawing, namely Fc'25 Mpa which takes 1 day to complete the 6 columns, casting assisted by using a concrete vibrator and a concrete pump, the concrete is left to rest for 12 hours and then the formwork is dismantled, then it is necessary to curing the concrete for 7 days until the concrete is ready to do the paint finishing work, then proceed to the paint finishing stage by painting the cabbage surface om.
Figure 3. Concrete Column Work
In Figure.4 based on field observations, the duration of work on the concrete column for heavy equipment warehouse 1 takes 20 days, the work is carried out from Monday to Saturday Based on field observations, concrete column work starts from 1 July 2020 to 28 July 2020 as many as 20 days.
Figure 4. Duration of Work on Concrete Columns for Heavy Equipment Warehouse 1
Based on the results of field observations, the steps for heavy equipment warehouse steel column work 2 are in accordance with (Figure 4.14) starting from steel fabrication work according to order, steel fabrication is carried out in a steel workshop in other words not done on site, fabrication of steel beams and columns WF 250,125 .6.9 only takes 7 days to fabricate, along with the steel fabrication time, the steel column anchors are installed according to the planned point, the anchor installation takes 3 days, then the steel that has been fabricated is continued with steel erection work which is also simultaneously an erection of steel beams is carried out which functions as a lock so that the steel column remains safe and upright, in steel erection work is assisted by using 2 units of mobile crane, 1 unit functions as material mobilization and 1 unit functions for steel erection. in 1 day able to erect as many as 7 columns. after the steel is installed, then do grouting work and finally continue with the steel paint finishing work.
In (Figure 6) based on field observations the duration of the work time of the steel column in heavy equipment warehouse 2 takes 12 days. Steel column work starts from 10 August 2020 to 25 August 2020 and takes 12 days.
Figure 5. Steel Column Work
Figure 6. Duration of Work Time for Heavy Equipment Warehouse Steel Columns 2
4. Concolusion
From the results of the analysis of the calculation of time and cost of work on the concrete column for heavy equipment warehouse 1 and steel column for heavy equipment warehouse 2 on the Cileungsi Workshop Development project, several conclusions can be drawn, including the following:
4.1. The difference in the cost of working for concrete column for heavy equipment warehouse 1 and steel column for heavy equipment warehouse 2
The cost of heavy equipment warehouse 1 concrete column work is Rp. 216,372,808, while the cost of working on steel columns in heavy equipment warehouse 2 is Rp. 282,911,957, then the difference between the cost of heavy equipment warehouse 1 concrete column and heavy equipment warehouse 2 steel column is Rp.
Rp. 66,539,148, If you want to prioritize costs, it is recommended that cheaper column work is recommended to use columns with concrete material, because concrete columns are cheaper than steel columns.
4.2. Time difference for heavy equipment warehouse concrete column 1 and heavy equipment warehouse steel column 2
The working time of the heavy equipment warehouse concrete column 1 is 20 days, while the steel column work time in the heavy equipment warehouse 2 is 12 days, then the time difference between the heavy equipment warehouse concrete column work 1 and heavy equipment warehouse steel column 2 is 8 days, if you want to prioritize When working columns are faster, it is recommended to use columns with steel material, because steel columns are faster than concrete columns.
Suggestion
1.
In calculating the cost of steel, it is advisable to calculate the fabrication costs and material mobilization if the fabrication is carried out in a workshop2.
In the duration of concrete column work, the age of the concrete that has been cast must be considered so that the concrete column is ready for paint finishing.3.
For further research, it is advisable to use the unit price with the coefficients used in the project, so that the analysis results are closer to actual application.References
SNI 7393 2008. (2008). ANALISA PEKERJAAN BESI DAN ALUMINIUM.
SNI 7394:2008. (2008). Tata cara perhitungan harga satuan pekerjaan beton untuk konstruksi bangunan gedung dan perumahan.
