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Keretakan Beton Pada Bangunan dan Cara Perbaikannya

JURNAL R & B Vol 3, No 2 (2003)
Publisher : JURNAL R & B

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Abstract

There is a crack that usually occurs on the structure of concrete. This crack commonly called hieroglyphics. They look like an illustration that can’t be used as the medium. There fore, it needs further reference and analysis about this hieroglyphics. Some elimination or concrete test that have been conducted showed that this crack would be caused by the concrete itself while it was still wet. Perhaps, the crack occurs because of the untrydration cement. Another possible factor may be due to the waker that conducts hydration so the cement become harder.

Perbandingan Pemakaian Microwave Oven and Oven Standard Untuk Menentukan Kadar Air Aggregat dan Beton Segar

JURNAL R & B Vol 2, No 1 (2002)
Publisher : JURNAL R & B

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Abstract

Absorbing process of on “aggregat” can be usad es an assential clue in determining the exact values of water resistance and the cerpability of that concrete, if it is applied in natural condition will take a quite long of time. Therefore its necessary utilitize microwave. For this research, the concrete is divided into three mixtures, based on watering fac of cement which shows, 3 , 0,5 * 0,7. The of these mixtures will be compared with standed oven. The research proves that microwave oven can be used to measure water content both smooth and rough aggregat. As well as in the concrete. The data shows that it takes about 8 minutes for dry the smooth aggregat and 10 minutes for rough aggregat and finally it is two times faster to observe the water persentage for concrete

Klaim Pada Proses Konstruksi Yang Diajukan Oleh Kontraktor

REKAYASA SIPIL Vol 6, No 1 (2010)
Publisher : REKAYASA SIPIL

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Abstract

Klaim konstruksi terhadap gedung yang diajukan oleh kontraktor kepada owner selama proses konstruksi berlangsung hampir selalu terjadi dalam proyek-proyek konstruksi, maka diperlukan pemahaman yang baik tentang pengajuan klaim yang dapat membantu para kontraktor dalam proses pengajuan klaimnya. Klaim yang timbul dari atau sehubungan dengan pelaksanaan suatu pekerjaan jasa konstruksi antara pengguna jasa dan penyedia jasa atau antara penyedia jasa utama dengan sub penyedia jasa atau pemasok bahan atau antara pihak luar dan pengguna/penyedia jasa yang biasanya mengenai permintaan tambahan waktu, biaya atau kompensasi lain. Dalam industri konstruksi, klaim diajukan untuk mendapatkan tambahan waktu atau tambahan biaya. Tambahan biaya bukan diajukan oleh kontraktor saja, tetapi bisa juga oleh owner, atau keduanya tergantung situasi yang terjadi. Berdasarkan jenis klaim, klaim yang dapat diterima yaitu penyedia jasa hanya mendapatkan tambahan waktu. Keterlambatan dengan kompensasi (ganti rugi), penyedia jasa mendapat perpanjangan waktu dan ganti rugi. Klaim yang tidak terpenuhi berpotensi menjadi konflik atau persengketaan yang akan memberi efek pada kelancaran proyek. Penyelesaian sengketa konstruksi pada umumnya lebih disukai melalui arbitrase daripada pengadilan.

Pembuatan Sumur Resapan Dari Bambu Untu

REKAYASA SIPIL Vol 6, No 2 (2010)
Publisher : REKAYASA SIPIL

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Abstract

Masyarakat pedesaan umumnya memiliki taraf ekonomi dan pendidikan yang rendah . Dimana mayoritas penduduknya bergerak di bidang pertanian atau perikanan ( nelayan ). Sumur resapan untuk daerah pedesaan perlu dibuat sederhana yang disesuaikan dengan kondisi lingkungan pedesaan. Masyarakat pedesaan umumnya memiliki taraf ekonomi dan pendidikan rendah. Bahan-bahan yang pakai harus murah dan mudah didapat dilokasi sehingga mudah diterima dan diterapkan oleh masyarakat.Desa yang memiliki banyak tanaman bambu dapat mengembangkan model sumur resapan dari bambu yang dianyam. Sumur resapan merupakan sumur atau lubang pada permukaan tanah yang dibuat untuk menampung air hujan agar dapat meresap ke dalam tanah. Dengan sumur resapan ini air hujan akan ditampung dan diresapkan ke dalam tanah sehingga dapat memperbaiki permukaan air tanah serta mengurangi aliran permukaan. Disamping itu juga akan meningkatkan kemampuan tanah dalam meresapkan air.Pembangunan yang tidak terkendali secara langsung akan mengurangi daerah resapan air. Dengan membuat sumur resapan merupakan upaya untuk memperbesar resapan air hujan ke dalam tanah dan memperkecil aliran permukaan sebagai penyebab banjir. .Kostruksi sumur resapan ini dibuat dari anyaman bambu berbentuk lingkaran dengan diameter 1 m dan tinggi 2 m.

Pengaruh Asam Akrilat Terhadap Sifat Mekanis Papan Partikel dari Serbuk Kayu Kelapa Sawit, Polypropilena Bekas Dan Urea Formaldehida

POLI REKAYASA Vol 1, No 2 (2006)
Publisher : POLI REKAYASA

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Abstract

The research of making particle board of OPT powder, waste polypropylene (pp) and urea formaldehyde had investigated. Waste polypropylene as the reinforcer was modified with acrilyc acid coused has the polar function group ( pp-ak), so it can interacted with OPT’s cellulose. It can increased the mechanical property and stability dimension of particle board. The making of particle board was carried out by mixing OPT powder, pp-ak and urea formaldehyde. The pp-ak composition were 5, 10, 15, 20, 25, 30% and urea formaldehyde was 10% of the weight. The mixing of the materials was carried out at the melting point of the pp-ak ( ± 70 C ) and then they had to formed. The curing process was done in the Hot-Press mechine at the melting point of the pp-ak temperature. The sample of particle boards were characterized include mechanical test, fisical test and chemical test ( FT-IR ). The result showed that the addition ( modification )   waste pp with  acrilyc acid can increased the mechanical property and stability dimension of the particle board. From analyses of the FT-IR showed there were interacted  between OPT’s cellulose and pp-ak, that is hidrogen bridge.

Pengaruh Penambahan Serat Tandan Kosong Kelapa Sawit Terhadap Kuat Tekan dan Kuat Tarik Belah Beton

POLI REKAYASA Vol 1, No 1 (2005)
Publisher : POLI REKAYASA

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Abstract

The weakness of concrete as the construction materials is that it is not strong enough of withstanding the tensile stress. It is the reason that tensile column is needed for the reinforcement of concrete to the tensile stress occurred. In modern countries, there is a concept that has been developed to improve the lack of tensile strength of concrete by adding fiber into the concrete mix. Fiber concrete is a composite materials made up of concrete and a number of fiber. The basic principle of this concept is that fiber concrete is capabel to harden the concrete by scattering the fiber into the concrete mix, and this can avoid cracking occurred due to compressive load or heating. This research is focused on the infuence of adding a hollow bunch of oil-palm fiber into the compressive and split tensile stresses of concrete. For this purpose, it is carried out an experiment to examine 96 test materials of cylindrical concrete with standard measurement, 15 cm in diameter, and 30 cm heigh. The composition of concrete used in this research is the one with the water-cement ratio 0,58. The variety of additional fiber of the  hollow bunch oil palm into the concrete test is 0%, 0.1%, 0.2%, and 0.3% of the weight of the composition. Fiber of the oil-palm used in this research has been found in pasaman and it was cut in the length of 5 mm. The results reveals that there is a greatest increasing of compressive strength on the test material having 0.3% fiber as much as 4.3% of those tested materials. The research finding also indicated the significant and greatest increase of the split tensile strength on the test material with 0.3% fiber as muuch as 11.6% of the tested materials. Based on these research findings, it can be concluded that additional fiber of hollow bunch oil palm into concrete, but the influence is not too significant for the compressive strength to the cylindrical concrete.

Tudy Eksperimental Tentang Penambahan Abu Ampas Tebu Terhadap Kinerja Beton Normal ; Tinjauan Terhadap Kekuatan Tekan

POLI REKAYASA Vol 2, No 1 (2006)
Publisher : POLI REKAYASA

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Abstract

Concrete is the material that is basically as an important thing in a modern social life. Almost all of the daily life aspects much depend on the concerte, either as a direct or indirect aspects. Nowadays, the importence of concrete can be seen clearly in our real life especially in the building construction. There are more factories are built in many provinces in Indonesia and that is one of the indications that the capacities of our production also increase. Based on the inceasing need of the concrete, there is an alternative offered in this research by using the waste of sugar-reed instead of cement. The main reason is that the cost of cement has much been increased since the last few years. The purpose of this research is to compare the strength of the pressure for the concrete that has been added or mixed by the waste of sugar-reed. Besides, the importance of this research is also to prove that the composition of the mixed waste sugar-reed concrete can influence the strength of the pressure for the concreate than those of concreate with the less mixture of the waste of sugar-reed. Based on the research findings, it can be concluded that the greater strengthens of the additional waste sugar-reed concrete can be found on the concreate of 20% for the waste sugar-reed at the age of 28 days and the for having the strength at 40,365 Mpa, but for those concrete without adding the waste sugar-reed it is only at 34,753 M

Bambu Sebagai Pengganti Kawat Anyam Pada Pembuatan Ferro-Cement

POLI REKAYASA Vol 3, No 1 (2007)
Publisher : POLI REKAYASA

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Abstract

Ferro cement is a mix material between mortar and chicken wire sheet or small diameter steel mesh which is bound to be a rigid structure (Nugraha, 1992). The cement mortar is functioned as a mass while steel wire give strength and ductility (Tjokrodimuljo, 1994). Any material functioned as Ferro cement must fulfill categories required. One material that can be used as the replacement of plaited mats wire or steel wire is bamboo. Bamboo is important material that may replace the use of wood. Hence, it can be found in many counties in West Sumatra. Besides, bamboos also have been utilized as replacement of bones for the basin of rainwater (cement bamboo basin) that give a good strength. The research varies the Ferro cement bones into three, namely chicken wire bones, 4 mm thick bamboo bones and 5 mm thick bamboo bones. The Bamboo is cut 250 cm long and then split in accordance with the thickness needed. While the comparison of volume cement and sand is 1 : 2. The result of comprehensive strength test indicates that the biggest value of comprehensive strength goes to the Ferro cement using chicken wire bones (212,926 kg/cm2). The result value of shear strength test also shows that this kind of bones is the biggest (147,640 kg/cm2), while the deflect strength of the three variations show the nearly value.

Sabut Kelapa Sebagai Bahan Drainase Pada Lapisan Tanah Dasar Jalan Raya

POLI REKAYASA Vol 7, No 1 (2011)
Publisher : POLI REKAYASA

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Abstract

Problems that often occur on the highway  built on the soil slabs is the roads are easily damaged, wavy, perforated, and even the ways decrease mainly due to the water. Drainage material  commonly used is the synthesis materials, known as coconut geotextile fiber, that is one of the alternative materials used as drainage material because the coconut geotextile fiber is water permeable that make it easy to pass. The coconut fiber used is made ​​like mattress (the mattress with an open pattern, tightly woven, and the elongated channels) and laid on the surface layer of the road subgrade. Tests conducted in the laboratory with a small scale, using the test box length = 50 cm, width = 30 cm, and height = 40 cm. Soil is compacted into a test box as high as 15 cm and then is saturated for 24 hours. The mattress of coconut geotextile fiber is spread on the surface of the soil and then carried out the preloading. The pressures of pore ​​water that exist in the soil will rise because of the given load, so that water will find a more permeable area such coconut fiber mattress that serves as drainage. Water that comes out through the drain of coconut fiber given load for 15 days is 0.76%  for mattress with tightly woven mattress pattern, open mattress pattern = 5379%, and the elongated channels  = 3.842% The free compressive strength of soil increased simultaneously with the decrease of water from the soil,  and the increasing value of free compressive strength of  soil is greater than 2.5 times compared with the prior installation of coconut fiber drainage.

KARAKTERISTIK SIFAT MEKANIS TANAH LEMPUNG TERHADAP KADAR AIR (KAMPUS UNAND LIMAU MANIS PADANG)

Rekayasa Sipil Vol 4, No 1 (2015)
Publisher : Universitas Mercu Buana

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Abstract

Kampus Universitas Andalas dan Politeknik Negeri Padang terletak di lereng bukit, tanah dasarnya didominasioleh lapisan lempung yang rentan terhadap perobahan kadar air. Kekuatan geser tanah ini sangat dipengaruhioleh kandungan air yang ada dalam tanah tersebut.Penelitian ini dilakukan untuk mendapatkan pengaruh kadar air terhadap kekuatan geser tanah, yaitu dengancara penambahan air secara bertahap (bervariasi), mulai dari kadar air dibawah Liquid Limit dan diatas kadar airLiquid Limit. Dan dilanjutkan dengan pengujian kuat geser masing masing variasi.Pengujian dilakukandilakukan dengan variasi kadar air mulai dari 40% , 50%, 55%, 60% dan 70% .Hasil analisa memperlihatkan bahwa jenis tanah di kampus Unand-Politeknik termasuk jenis MH-OH(klasifikasi USCS) yaitu tanah lempung-lanau dengan plastisitas tinggi.Nilai kohesi tanah lempung-berlanau (MH-OH) sangat dipengaruhi oleh kadar air, jika kadar air > 40%, nilaipara kuat geser (kohesi) tanah secara siknifikan menurun drastis. Sedangkan penurunan nilai kuat geser tanahdari kondisi asli sampai mencapai ± 75% . Hal ini menunjukkan bahwa kekuatan geser tanah lempung sangatrentan terhadap perobahan kadar air.