Civil Engineering Dimension (E-Journal)
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MANAGING THE BUILDING DESIGN PROCESS FOR SUSTAINABILTY AND IMPROVED QUALITY
Get PDFThe essence of building design process and management for building sustainability in the creation and maintenance of a qualitative architectural product is investigated in this paper. The design process, concept of building sustainability and particularly the quality of the built environment are discussed. Akure, a state capital in Nigeria was used as a case study. The principles and indicators for sustainability of buildings and its implications on the quality of the environment are examined in details. Survey findings include the views of the professionals on the clients, perception on the design process as well as management of projects, and the implications on the quality of the ensuring products and the city’s environment. The data were factor analyzed using varimax rotation criterion (with Kaiser Normalization). The results revealed that five factors were effective, with one of them exhibiting the greatest variability and individual differences. The variables that loaded on this factor were really the aspects of the process and management relating to the clients. The findings also revealed the professionals’ wrong attitude towards design process as shown with a very high degree of variability in the study. The paper concludes by recommending the enactment and enforcement of relevant policies with adequate education of the people and the involvement of all the stakeholders in the management of building projects and environmental programmes for the realization of a qualitative architectural product
SLAB FORMWORK DESIGN
Get PDFNote from the Editor:
In Indonesia, although cost of formwork contributes significantly to the total reinforced concrete construction cost and formwork failure will result in a very complicated construction problem, formwork design is often neglected and left to the foreman to design. This paper presents slab formwork design practice in Romania, where formwork design is a requirement to obtain professional engineer certification. This paper is a continuation of previous paper ” Wall Formwork Design” by the same author published in Dimensi Teknik Sipil, Vol. 6, no. 2, September 2004.
Abstract in Bahasa Indonesia :
Catatan Redaksi:
Perencanaan bekisting (form work) di Indonesia sering kali dilalaikan dan diserahkan kepada pelaksana/ mandor, padahal kegagalan bekisting akan menimbulkan masalah yang sangat rumit. Bekisting juga merupakan komponen biaya pelaksanaan struktur beton bertulang yang cukup besar. Makalah ini memaparkan praktek perencanaan bekisting untuk lantai di Romania, dimana perencanaan bekisting merupakan salah satu syarat untuk mendapatkan sertifikasi insinyur professional. Makalah ini adalah kelanjutan dari makalah Wall Formwork Design, yang dimuat dalam Dimensi Teknik Sipil, Vol. 6, no.2, September 2004
TINGKAT KEPERCAYAAN DALAM HUBUNGAN KEMITRAAN ANTARA KONTRAKTOR DAN SUBKONTRAKTOR DI SURABAYA
Get PDFKemitraan merupakan salah satu solusi manajemen untuk meningkatkan kinerja dan mempererat hubungan antar partisipan dalam proyek konstruksi. Penelitian ini bertujuan untuk mengukur tingkat kepercayaan dan membahas kepercayaan sebagai salah satu faktor sukses kunci kemitraan antara kontraktor dan subkontraktor di Surabaya. Data diperoleh dengan survei menggunakan kuesioner untuk mengukur empat elemen tingkat kepercayaan berdasarkan teori Robert Bruce Shaw, yaitu: exhibiting trust, achieving results, acting with integrity dan demonstrating concern. Hasil penelitian menunjukkan bahwa secara umum tingkat kepercayaan antara kontraktor dan subkontraktor di Surabaya berada pada tingkat tinggi. Selain itu, penelitian ini juga menemukan adanya perbedaan tingkat kepercayaan, yang disebabkan oleh lama pengalaman di bidang konstruksi dan lama bekerja seorang individu di perusahaan yang bersangkutan, serta jenis proyek yang dikerjakan dan nilai pekerjaan yang disubkontraka
PENGARUH ARAH SAYAP PELIMPAH SAMPING DAN KEDALAMAN ALIRAN TERHADAP KOEFISIEN DEBIT
Get PDFSide weir is a type of protection structure which function is to protect channels from damage caused by excessive amount of water (overtopping) so the water level in channels or rivers is to be preserved. The type is spatially varied flow with decrease of discharge occurs in main channels along the side weir. Usually design of spillway applies entrance of slope 900. Thus this reduces discharge coefficient. In this research, the influence entrance slope less than 900 was observed such as 600 and 300. The observation showed that discharge coefficient is function of entrance slope and ratio value of water depth to weir radius (h/r) with largest discharge coefficient around value (0.341 – 0.366) with entrance slope value (55.850 – 57.730).
Abstract in Bahasa Indonesia :
Pelimpah Samping (side weir) adalah bangunan untuk melindungi saluran dari kerusakan yang diakibatkan oleh jumlah air yang berlebihan (overtopping). Dengan dipasang pelimpah samping maka ketinggian air di saluran atau sungai tetap terjaga. Tipe aliran adalah aliran berubah lambat laun terhadap ruang (spatially varied flow) dengan penurunan debit yang terjadi di saluran utama sepanjang pelimpah. Selama ini pembangunan pelimpah samping menggunakan sudut masuk 900 terhadap aliran utama. Dengan demikian mempunyai kerugian yakni berkurangnya koefisien pengaliran. Dilain pihak asumsi koefisien pengaliran tersebut sampai sekarang tetap dianggap cukup besar. Pada penelitian ini diamati pengaruh sudut masuk sayap yang lebih kecil dari 900 yaitu sudut 600 dan 300. Hasil penelitian menunjukkan bahwa koefisien debit merupakan fungsi dari sudut masuk dan nilai perbandingan kedalaman air dan jari-jari pelimpah (h/r). Koefisien debit terbesar bernilai antara (0,341 – 0,366) pada sudut masuk antara (55,850- 57,730)
PENELITIAN MENGENAI PENINGKATAN KEKUATAN AWAL BETON PADA SELF COMPACTING CONCRETE
Get PDFHigh Early Strength Self Compacting Concrete, a new phenomenon in the world of concrete technology, offers advantages such as high workability, high durability and high early strength characteristic that can well be applied especially in the pre-cast concrete industry. In this study the properties of High Early Strength Self Compacting Concrete is achieved by the use of admixture (hyper plasticizer) Glenium Ace-80 and Silica Fume Rheomac SF 100 as filler. The water-binder ratio is kept in the low level. The workability conditions are tested using workability test like Slump Cone, V-Funnel, and L-Shaped Box. To test the High Early Strength characteristic compression tests are carried out on 1, 3, 7, 14 and 28 days of concrete age. The tests were focused on the age 1 and 28 days. The test result shows that the use of 2.5 % Glenium Ace-80 and 2 % Silica Fume can fulfill both workability and high early strength requirement of Self Compacting Concrete High Early Strength by keeping the value of water-binder ratio in the low level.
Abstract in Bahasa Indonesia :
High Early Strength Self Compacting Concrete (HESSCC), sebuah fenomena baru dalam dunia teknologi beton, memiliki keunggulan workability, durabilitas dan kekuatan awal yang tinggi, sehingga dapat diaplikasikan dengan baik khususnya pada dunia usaha pre-cast concrete. Dalam penelitian ini digunakan admixture (hyperplasticizer) Glenium Ace–80 dan filler Silica Fume Rheomac SF 100 dengan water-binder ratio rendah. Pengujian workability dilakukan dengan menggunakan alat Slump Cone, V-Funnel dan L-Shaped Box, sedangkan tes kuat tekan beton dilakukan pada umur 1, 3, 7, 14, 28 hari. Tes kuat tekan ini diutamakan untuk umur 1 hari untuk kuat tekan awal dan 28 hari untuk kuat tekan akhir dari beton. Hasil penelitian menunjukkan penggunaan Silica Fume sebesar 2 % dan Glenium Ace-80 sebesar 2.5 % sudah mampu mencapai kriteria self compactible sekaligus kuat tekan awal (High Early Strength) yang baik pula, karena nilai water-binder ratio tetap dijaga pada nilai yang renda
STUDI TENTANG DAKTILITAS STRUKTUR PADA SISTEM SHEARWALL FRAME DENGAN BELT TRUSS
Get PDFPrevious researches have shown that belt truss could function very well as (virtual) outrigger in the elastic region, the non-linear behaviour of the structural system has not been studied. In this study the performance of a 30 story shearwall-frame-belt truss structure which is designed using structural ductility equal to 3.75 is evaluated using dynamic nonlinear time history analysis. The earthquake loads used are spectrum consistent acceleration in accordance to the Indonesian Earthquake Code, SNI 03-1726-2002 modified from the North-South components of El Centro, May 18, 1940 with return periods of 27, 67, 135, 260, 500, and 1050 years. It is shown that for the structure considered in this study, a structural ductility of 3.75 could not be used, since some structural elements fail (damage index > 1) at 135 years return period.
Abstract in Bahasa Indonesia :
Beberapa penelitian yang telah dilakukan menunjukkan bahwa belt truss dapat berfungsi dengan baik sebagai (virtual) outrigger, tetapi penelitian-penelitian tersebut hanya meninjau prilaku elastis dan belum meninjau prilaku nonliner struktur akibat gempa besar. Dalam penelitian ini prilaku nonliner sebuah struktur shearwall-frame–belt truss 30 tingkat yang direncanakan dengan daktilitas struktur sebesar 3.75, dievaluasi menggunakan analisis dinamis non-linier riwayat waktu. Rekaman gempa yang digunakan sebagai beban adalah gempa El Centro 18 Mei 1940 komponen North – South yang dimodifikasi agar mempunyai respons spectrum sesuai dengan SNI 03-1726-2002 dengan periode ulang 27, 67, 135, 260, 500 dan 1050 tahun. Hasil penelitian menunjukkan untuk struktur yang ditinjau, daktilitas struktur 3.75 tidak dapat digunakan, karena pada gempa dengan periode ulang 135 tahun, beberapa elemen struktur telah mencapai damage index lebih dari satu (melewati batas safety limit state)
STRENGTH SHRINKAGE AND CREEP OF CONCRETE IN TENSION AND COMPRESSION
Get PDFStrength, shrinkage and creep of concrete in tension and compression have been determined and the relationship between those properties was studied. Direct tensile tests were applied to measure those properties in tension. The relationship of creep in tension and compression was determined based on the measurement of creep at similar stress and similar stress/strength ratio. It is found that concrete deforms more in tension than in compression. Except for concrete with a higher water/cement ratio, the use of pulverised fuel ash, ground granulated blast furnace slag, superplasticizer and shrinkage reducing admixture has no effect on strength. However, they affect creep and shrinkage of concrete
PENGARUH ELEKTROKINETIK TERHADAP DAYA DUKUNG PONDASI TIANG DI LEMPUNG MARINA
Get PDFElectrokinetics is one of soft ground improvement methods to improve its bearing capacity. The objective of this research is to investigate the increase of friction and end bearing resistance of an embedded instrumented model pile in marine clay after electrokinetics treatment. The initial geotechnical properties of soil surrounding the pile foundation is obtained by several soil laboratory tests. For pile bearing capacity analysis, friction and end bearing resistance of pile was measured by load cell measuring device, while un-drained shear strength analysis was measured by vane shear test. The result of this research showed that after 24 hours electrokinetics treatment, the un-drained shear strength increased closer to the pile, and the bearing capacity of pile increased 14 times.
Abstract in Bahasa Indonesia :
Elektrokinetik adalah salah satu metode perbaikan tanah lunak yang diaplikasikan untuk meningkatkan daya dukung tanah lunak. Tujuan dari penelitian ini adalah untuk menyelidiki peningkatan tahanan friksi dan ujung suatu model pondasi tiang di lempung marina setelah dilakukan proses elektrokinetik. Karakteristik tanah pada kondisi mula-mula di sekitar pondasi tiang didapatkan dari beberapa pengujian di laboratorium. Untuk analisa daya dukung tiang, tahanan friksi dan ujung dari pondasi tiang diukur dengan alat pengukur load cell, sedangkan analisa kuat geser undrained diukur dengan pengujian baling-baling. Hasil penelitian menunjukkan bahwa setelah pada tanah dilakukan proses elektrokinetik selama 24 jam, daya dukung dari pondasi tiang meningkat 14 kali dan semakin dekat dengan tiang, kuat geser undrained juga semakin meningkat
PENGARUH VARIASI TEKANAN KEMPA TERHADAP KUAT LENTUR KAYU LAMINASI DARI KAYU MERANTI DAN KERUING
Get PDFThe use of timber as a structural material is not only limited to solid timber but also as laminate called glue-laminated timber (glulam). The design of glulam depends on many factors such as the expertise of the designer, timber grade and its combination, adhesive quality, gluing process and clamping process. This research explores the optimum clamp pressure to obtain maximum bending strength of glulam timber which is a combination of Keruing and Meranti Woods using Polivynyl Asetat (PVA) and Melamin Formaldehyde (MF) adhesives. The combination of timber for shear specimen are Keruing Meranti Keruing (KMK), Keruing Keruing Meranti (KKM), and Keruing Meranti Meranti (KMM), the clamp pressures used are 0,2 MPa, 0,6 MPa, 1,0 MPa, and 1,4 Mpa. The duration of clamping is six hours for all combination. The result shows that the bonding strength of shear specimen reaches a maximum of 75,13 kg/cm2 with a clamp pressure of 0,6 MPa using MF adhesive. The maximum flexural strength achieved is 656,37 kg/cm2 with a clamp perssure of 0,6 MPa using MF adhesive as well.
Abstract in BahasaIndonesia :
Pemakaian kayu sebagai bahan struktural tidak hanya terbatas sebagai kayu utuh, tetapi juga sebagai balok laminasi atau glulam. Proses perancangan kayu dipengaruhi beberapa faktor seperti, tingkat keahlian perancang, faktor kayu yang digunakan beserta kombinasinya, perekat dan proses perekatannya serta proses pengempaannya. Penelitian ini mencari besar tekanan kempa optimum untuk mendapatkan kekuatan lentur maksimum kayu laminasi dari kayu Keruing dan Meranti yang direkatkan dengan perekat Polivynyl Asetat (PVA) dan Melamin Formaldehyde (MF). Kombinasi yang digunakan pada benda uji lamiasi adalah Keruing Meranti Keruing (KMK), Keruing Keruing Meranti (KKM), dan Keruing Meranti Meranti (KMM), dengan tekanan kempa rencana sebesar 0,2 MPa, 0,6 MPa, 1,0 MPa, dan 1,4 MPa untuk semua kombinasi. Proses pengempaan dilakukan selama enam jam. Hasil pengujian pada benda uji kuat lekat menunjukkan keteguhan rekat maksimum sebesar 75,13 kg/cm2 dicapai dengan tekanan kempa 0,6 MPa dengan perekat MF. Sedangkan pada balok laminasi kuat lentur maksimum mencapai 656,37 kg/cm2 pada tekanan kempa 0,6 MPa dengan kombinasi kayu Keruing Meranti Keruing dan perekat MF
THE PERFORMANCE OF TRADITIONAL CONTRACT PROCUREMENT ON HOUSING PROJECTS IN NIGERIA
Get PDFThe traditional contract procurement has been widely criticized as an ineffective procurement method because it often involves time and cost overrun on construction projects. Yet the method is still being widely used in Nigeria most especially for the procurement of housing projects. It is suspected that this procurement method may not be ineffective in all cost categories of housing projects. Therefore time and cost performances of the procurement method on 57 housing projects of varying cost categories initiated by the Nigerian government between 1993 and 1999 were studied. The category of one to five million naira (US$1.00 ≈ 92 Nigerian Naira in 1999) showed the least time overrun of 18.98% while the highest time overrun of 99.64 % was shown in the five to ten million naira. The over ten million naira category had the least cost overrun of 9.13% while the highest cost overrun of 34.55 % was shown in the less than one million naira. The one to five million naira cost category exhibited weak correlation between time and cost overruns but the five million naira and above categories showed strong correlation. It was concluded that one to five million naira cost category is quite suitable for traditional contract procurement on housing projects in Nigeria