Peranan Tulangan Tekan Pada Balok Terlentur Tulangan Rangkapuntuk Membangkitkan Momen Nominal

Installation of compression reinforcement in the flexural beam can not be avoided . Two things which are coercive ,ie tying stirrup and high of beam restricted by the architect . Flexural beam is calculated based on the design moment . Design moment is the nominal moment multiplied by reduction factor Φ . Nominal moment is the sum of the two parts of the nominal moment . The first nominalmoment call Mn1 , ie couple between tensile force of the first tensile reinforcement NT1 = As1.fy with concrete compressive force ND = 0.85 fc '.a.b . Second nominal moment Mn2 , which is couple between the second tensile reinforcement force NT2 = As2.fy with the force of compression reinforcement ND ' = As'. Fs' . By adding compression reinforcement is expected to rise as well nominal moment . After analyzed here are four conclusions can be drawn .First , the beam does not always require compression reinforcement . Second , if the compression reinforcement is installed too deep will cause its stress decreases , it can even be ignored. Third , the compression reinforcement additional is not comparable with the nominal moment increament. The more aditonal of the compression reiforcement , the smaller the ratio of nominal moment we get. Fourth , the increase in the second nominal moment Mn 2 can continue to be done by the limit only by the availability of the place of installation

The Effect of Styrofoam Artificial Lightweight Aggregate (ALWA) on Compressive Strength of Self Compacting Concrete (SCC)

Self-compacting concrete (SCC) is a fresh concrete that is able to flow and fill up the formwork by itself without the need of a vibrator to compact it. One of the reasons that causes the damage of a building structure during an earthquake is the heavy weight of its structural members which are from the high density of the material used such concrete material. Lightweight aggregate is one of the solutions to reduce the weight of the structure. Therefore, the SCC using the artificial lightweight aggregate (ALWA) is one of the solutions to reduce the self-weight (dead load) of a structure. This research was conducted to investigate the impact of the use of ALWA in conventional concrete and SCC in terms of its compressive strength and modulus of elasticity. To study the impact of the use of ALWA in SCC, several variation of percentage of ALWA as a substitution to the natural coarse aggregate was examined. The proportions of ALWA as a replacement to the coarse aggregate were 0%, 15%, 50%, and 100%. The test specimens were the cylindrical concrete of 200 mm in height and 100 mm in diameter for both compressive strength and modulus of elasticity tests. The results of the compressive strength test indicated that the higher the percentage of ALWA used in SCC, the lower the compressive strength of the concrete. The addition of ALWA as a substitution to the natural coarse aggregate to conventional concrete and SCC was found optimum at 15% replacement with the compressive strength of conventional concrete and SCC of 21.13 and 28.33 MPa, respectively. Whereas, the modulus of elasticity of the conventional concrete and SCC were found to be 20,843.99 and 23,717.77 MPa, respectively

Pengaruh Penambahan Gula Pasir Terhadap Setting TIME Semen Dan Kuat Tekan Mortar Yang Menggunakan Pasir Lokal

Paper ini merupakan hasil penelitian tentang variasi campuran mortar yang mempertimbangkan pengaruh kadar semen, faktor air semen dan kadar gula pasir terhadap performa campuran. Pertama ditinjau pengaruh kadar gula yang diberikan terhadap berat semen pada waktu ikat awal dan ikat akhir semen. Kemudian ditinjau kuat tekan mortar dengan berbagai varian sampel yang merupakan kombinasi FAS (0,4; 0,45; 0,5), komposisi adukan semen-pasir (1:5; 1:6; 1:7) dan persentase gula terhadap berat semen (0%; 0,05%; 0,1%; 0,15%;0,2%).Pengujian menunjukkan bahwa penambahan gula membuat pengikatan semen semakin naik secara signifikan hingga kadar tertentu seiring penambahan kadar gula dan kembali turun setelah melewati kadar 0,15%. Tren yang hampir sama berlaku pada kuat tekan mortar akibat pengaruh kadar gula. Faktor air semen juga berpengaruh pada kuat tekan dimana kadar air yang terlalu sedikit menjadikan kekuatan mortar tidak baik karena workability yang rendah. Sedangkan jumlah semen yang lebih banyak menjadikan kekuatan tekan mortar lebih tinggi

Compressive Strength of Steel-Fiber Concrete with Artificial Lightweight Aggregate (ALWA)

In the last decade, there have been many innovations developed to replace the aggregate as material for concrete, particularly the coarse aggregate using the artificial lightweight aggregates a.k.a. ALWA. In the study, the main ingredient used to develop the artificial lightweight aggregates is the styrofoam. Styrofoam has a lightweight characteristic so that it can reduce the density of the concrete. If the density of the concrete can be lighter than the normal-weight concrete then the overall weight of the structure of a building will also be lighter. Thus, the shear force due to the earthquake will also be smaller so that the safety of the building becomes better. The styrofoam used was dissolved with the acetone solution and formed into granules in which the size resembled the coarse aggregate size of about 10 to 20 mm. The styrofoam which has been formed then dried up so that the texture becomes hard. In addition, steel fiber was also used as an added ingredient in concrete mixtures so that the concrete was highly resistant against cracking and was expected to increase the compressive strength of the concrete. ALWA compositions used to replace coarse aggregates were 0%, 15%, 50%, and 100%. While the composition of steel fiber used was 0%, 0.75%, and 1.5% of the total volume of the cylinder. The type of steel fiber used was hooked-end steel fiber with the diameter and the length of 0.8 mm and 60 mm, respectively. The results showed that the concrete with 15% styrofoam ALWA and 1.5% of steel fiber were able to produce optimum compressive strength by 28.5 MPa and the modulus of elasticity by 23,495 MPa. In addition, the use of Styrofoam ALWA as a substitution to the coarse aggregate can reduce the density of concrete as much as 5 to 35%

Pengembangan Konsep Sistem Operasi dan Pemeliharaan (O&p) Daerah Irigasi Multiguna dengan Membangun Komitmen untuk Berbuat Konsensus Antar Pelaku : sebuah Kasus di Jawa Timur

On May 2006, the Government of Republic Indonesia launched the Government Rule (GR) no 20/2006 on irrigation. This GR replaced the previous GR no 77/2001 in the same issue. The changing of GR means also changing of implementation policy. Some constraints problems occurred and came up to hamper policy implementation in the field. Most of them mainly related to the changing of institution structure. The paper aims to discuss how local government and Gadjah Mada University try to solve the problems by developing a concept of solution. In this connection a discussion forum among stakeholder was set up. In the forum, university as a neutral scientific institution does as facilitator. The concept was tried to be implemented in two multipurpose irrigation schemes i.e. Bondoyudo and Siman, respectively in the multi year's basis. Those two schemes had several problems in irrigation management; one of them was conflict among users. In the first year some commitments and consensuses had already achieved by all stakeholders and would be implemented in the following years

Analisis Perhitungan Momen Balok Baja dengan Metode Jaringan Saraf Tiruan ( 1 - 4 )

Dalam kemajuan zaman saat ini perkembangan aplikasi teknologi berkembang sangat pesat. Perkembangan aplikasi teknologi membuat penelitian mengalami persaingan dalam hal penelitian aplikasi teknologi terbarukan. Diperlukan penelitian-penelitian aplikasi teknologi terbaru untuk mengikuti perkembangan zaman. Aplikasi teknologi terbaru saat ini yang sering digunakan adalah pengembangan program Matlab.Banyak hal yang dapat dikembangkan melalui program Matlab. Salah satunya adalah metode jaringan saraf tiruan. Jaringan saraf tiruan merupakan bahasa pemograman yang digunakan mengikuti pola data yang diinputkan. Melalui proses pembelajaran maka jaringan saraf tiruan dapat membuat data sama yang telah diinputkan dan dapat membuat data baru selama masih berada didalam batasan data yang telah diinputkan. Oleh karena itu akan penelitian ini akan menganalisis hasil perhitungan momen balok baja menggunakan jaringan saraf tiruan. Adapun data yang akan dimasukkan adalah data momen balok baja yang telah didapat menggunakan aplikasi Structural Analysis Program (SAP) 2000. Data momen balok baja yang diinputkan sebanyak 10 data dengan variasi panjang balok dan variasi beban merata. Momen balok baja yang didapat dari hasil jaringan saraf tiruan selanjutnya dihitung erornya dengan perbandingan hasil momen menggunakan SAP 2000. Dari hasil analisis didapatkan eror terkecil 0,13% dan proses training mengalami eror pada bacaan ke 9. Hal ini disebabkan oleh sedikitnya data yang diinputkan