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KUAT TARIK BELAH DAN LENTUR BETON DENGAN PENAMBAHAN STYROFOAM (STYROCON) Dharma Giri, I.B.; Sudarsana, I Ketut; Agustiningsih, N.L.P. Eka
Jurnal Ilmiah Teknik Sipil Vol. 12, No. 2 Juli 2008
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Application of lightweight material as former structure will reduce total weight of a building. Lightweight concrete is one of the lightweight structural former materials. In making of lightweight concrete, one of alternative material that used is styrofoam. Styrofoam generally used as materials that covering electronic things. Styrofoam use in lightweight concrete can be as air voids. The advantages of styrofoam than air void in lightweight concrete are that styrofoam have tensile strength. According to those, the aims of this research were to obtain the influence of adding styrofoam to volume of weight, splitting tension and modulus of rupture. The specimens for splitting test were cylinders with dimension of 150 mm in diameter and 300 mm in height and specimens for modulus of rupture were beam with dimension of 150 x 150 x 600 mm. Seven specimens were used for splitting test and 3 for modulus rupture test for any variation of percentage increased of styrofoam. Concrete was made by weight comparison of 1 : 2 : 3. The amount of cement in 1 m3 concrete mixture was 400 kg. Variation of percentage increased styrofoam were 0%, 10%, 20%, 30%, 40% to volume of mixture. The range diameter granular styrofoam are 3 – 10 mm with volume of weight of 22,89 kg/m3. Slump test is done to fresh concrete, volume of weight measurement, splitting and modulus rupture test were done after 28 days. Result showed that increased of styrofoam increased the slump value. Volume of weight and splitting tension decreased linearly. The adding of 10% granular styrofoam decreased the volume of weight and splitting tension by 81,08 kg/m3 (4,01%) and 0,34 MPa (12,19%), respectively. The change of modulus rupture value at 10% adding of styrofoam was 22,67% and at 20% adding of styrofoam was 29,62% to concrete without adding of Styrofoam. However at 30% adding of Styrofoam, modulus rupture increased by 1,21% to concrete with 20% adding of styrofoam.
INVESTIGATION OF WITHDRAWAL RESISTANCE OF LAG SCREWS FROM BANGKIRAY WOODS Sudarsana, I Ketut
Jurnal Ilmiah Teknik Sipil Vol. 9, No. 1 Januari 2005
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Lag screws are commonly used in knock down constructions where screwsis not possible. The resistance of the lag screws is provided by friction betweenthreaded parts and wood. This paper presents experimental investigation ofwithdrawal strength of lag screws embedded into Bangkiray woods. The objectives ofthe investigation were to determine the behavior of embedded screws subjected towithdrawal forces.To meet the experimental objectives, three specimens of an 8 mm diameter lag screwembedded into a 80 x 150 x 600 mm bangkiray woods were assembled and tested tofailure. The lag screws were 100 mm long with threaded length of 60 mm (effectivelength of 55 mm). However, in this experiment, only 40 mm of the threaded part waspenetrated into the main wood and giving the effective penetration length of 35 mm.Direction of the screw was perpendicular to wood grains. Two equal point loads wereapplied on both sides of the screws through two pieces of 50 x 70 x 500 mm bangkiraywoods connected using screws. The loads were increased incrementally every 1 kN or1kN/minute. Axial deformations of the screws were measured using a dial gaugelocated at the center of the lag screws for every load increment.The results show that failure modes occurred due to failure of the woods which werebearing failure of side beams and pull-out of the screws due to lose of main beamresistence. These types of failure were mainly dictated by the absence of washersbetween the bearing wood and the head of the screws. Slip of the embedded part atmaximum load is about 9.25% and 10.93% of the embedded length. The averagemaximum withdrawal strength of the screw embedded 40 mm into bangkiray wood is12.0 kN, excluding data of specimen S1. Prediction of withdrawal strength forembedment length of 60 mm is 24.10 kN.
INTERAKSI ANTARA GAYA AKSIAL DAN MOMEN PADA KOLOM BETON DENGAN TULANGAN BAMBU Sutarja, I Nyoman; Sudarsana, I Ketut
Jurnal Ilmiah Teknik Sipil Vol. 9, No. 1 Januari 2005
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The use of bamboo reinforcement in reinforced concrete structure has notbeen investigated extensively. The material is expected as an alternative of steel reinforcementin a certain condition. Therefore, this research is conducted to investigatethe capacity of columns reinforcing using bamboo in term of their axial strength andmoment as well as their interactions.Twelve columns reinforcing of bamboo are made and tested. Column dimensions of150 mm x 150 mm x 900 mm were cast using 15 MPa concrete obtained from ASTMstandard cylinder test of age of 28 days. Two group specimens based on its total reinforcementareas were made namely 400 mm2 and 600 mm2. Six variations were madefor each group to incorporate variation of applied load eccentricities during the test.The load eccentricities were 0 (pure axial), 70 mm, 100 mm, 150 mm, 200 mm and ¥(pure bending).Test results show that the experimental interaction between axial force and bendingmoment of the column reinforced with bamboo agree well with the analytical resultsfollowing the expression for column reinforced with steel reinforcement. Taking thetensile strength of the bamboo 50% of the rupture strength, give the experimentalcolumn capacities were close to the analytical results.
PEMODELAN PELENGKUNG BETON BERTULANG DENGAN MEMPERHITUNGKAN INTERAKSI TANAH DAN STRUKTUR (KASUS: ALTERNATIF RENCANA JEMBATAN SERANGAN – TANJUNG BENOA) Laintarawan, I Putu; Sukrawa, I Made; Sudarsana, I Ketut
Jurnal Ilmiah Teknik Sipil Vol. 10, No. 1 Januari 2006
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The Serangan-Tanjung Benoa Bridge is designed as a reinforced concretearch bridge as it usually built on hard soils, so it can be modelled as a fixed arch.However, the brigde was design on soft soil (N < 15) with hard soil (N > 50), 30 mbelow. Therefore, it is necessary to study the behavior of arch structure consideringsoil-structures interaction, due to vertical and lateral loads.Two models were made in order to model the soil-structure interaction: Model 1, thelateral soil supports is modelled as spring; Model 2, soil and foundation are modelledas solid element. Model 3, fixed arch was modelled without foundation. While modelling the soil as spring and solid, pile groups were asssumed as caisson and weremodelled as solid, and the elastic modulus of soil between piles is equal to the elasticmodulus of pile and its values were varieted and compared to the fixed model.Modulus of base soil lateral reaction, kh is modeled as spring with E of 28 N anduniformly distributed on caisson surface area behind the load. The finite elementmethod was made in 3D using SAP2000 program with static and time history analysisfor vertical and earthquake load, respectively.Soil modelled as spring and solid element in soil-structure interaction showcompatible, in which the deformation and internal forces varied by less than 2%. Themaximum deflection occurred on the peak of arch due to dead load of 191.4 mm, or37.87% smaller than the maximum deflection of the model including soil-structureinteraction. Moreover, fixed arch model has natural period of 2.37 second, which is0.39 second shorter than that including soil-structure interaction. With E greater than9000 MPa (sandstone type) the three models give deformation and internal forces itcompatible values with differences less than 2.2%.
BATASAN KEKAKUAN PONDASI PELAT KAKU DI ATAS TANAH ELASTIS Ardhana, Ketut; Sukrawa, Made; Sudarsana, I Ketut
Jurnal Ilmiah Teknik Sipil Vol. 10, No. 2 Juli 2006
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Pondasi pelat umumnya dirancang dengan anggapan distribusi reaksi tanah dasar adalah linier sehingga analisis dapat dilakukan dengan metode konvensional (metode rigid). Anggapan ini benar bila kekakuan pondasi memadai. Untuk pondasi pelat yang kurang kaku dipilih metode lain yaitu metode fleksibel, yang memperhitungkan variasi dari distribusi reaksi tanah dasar akibat pengaruh fleksibelitas pondasi dan perilaku elastis tanah dasarnya. Penelitian ini bertujuan mencari batasan kekakuan pondasi pelat yang dianggap kaku di atas tanah elastis. Metode penelitian dilakukan dengan menganalisis 2 (dua) tipe pondasi pelat yaitu pondasi pelat dengan kolom tunggal (pondasi pelat tunggal) yang terdiri dari 6 (enam) ukuran dan pondasi pelat gabungan dengan dua kolom (pondasi pelat gabungan) yang terdiri dari 5 (lima) ukuran. Pondasi tersebut ditumpu di atas tanah elastis dengan 12 (dua belas) variasi modulus reaksi tanah dasar (ks) yang berbeda. Analisis dilakukan dengan program berbasis metode elemen hingga dengan metode eksak sebagai pembandingnya. Dalam proses analisis, masa tanah dimodel sebagai kumpulan pegas (elastic spring) yang berdiri sendiri dan tidak saling berhubungan, sedangkan pondasi dimodel dengan elemen shell (shell element). Dari 132 sampel pondasi yang ditinjau, diperoleh hasil bahwa batasan kekakuan pondasi pelat kaku di atas tanah elastis, merupakan besaran tak berdimensi (?l) yang nilainya 0,79, dan tebal minimum pondasi pelat kaku dapat dinyatakan dengan Persamaan : 1,975. dimana Ec adalah modulus elastisitas material pondasi (kN/m2), ks adalah modulus reaksi tanah dasar (kN/m3), l adalah panjang pondasi (m) dan ? adalah persamaan karakteristik Pondasi pelat dengan tebal kurang dari tebal minimum d, dikategorikan sebagai pondasi fleksibel, dan oleh karenanya analisis sebaiknya memakai metode fleksibel untuk mendapatkan hasil yang lebih akurat.
PERKUATAN KOLOM BULAT BETON BERTULANG DENGAN LAPIS GLASS FIBER REINFORCED POLYMER ( GFRP ) Sudarsana, I Ketut; Gede Sutapa, A.A
Jurnal Ilmiah Teknik Sipil Vol. 11, No. 1 Januari 2007
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Penelitian ini dilakukan untuk mengetahui pengaruh perkuatan kolom bulat beton bertulang dengan metode jacketing menggunakan Glass Fiber Reinforced Polymer (GFRP) dengan panjang sambungan (overlapping) GFRP yang bervariasi terhadap perilaku keruntuhan, daya dukung aksial dan daktilitas aksial kolom. Sebanyak 21 buah silinder beton dengan diameter 150 mm dan tinggi 300 mm dibuat dan dites. Variasi panjang sambungan GFRP adalah 100%, 150%, 200%, 250% dan 300% dari panjang sambungan hasil perhitungan yang didasarkan pada kuat tarik dan kuat rekatan GFRP. Pengujian dilakukan dengan memberikan beban tekan pada benda uji sampai benda uji mengalami keruntuhan. Data yang dicatat dalam pengujian adalah perilaku runtuh, beban maksimum benda uji dan perpendekan longitudinal benda uji untuk setiap peningkatan beban sebesar 10 kN. GFRP dengan sambungan 100% dan 150% mengalami gagal geser pada sambungan sedangkan GFRP dengan sambungan 200% sampai dengan 300% gagal tarik (putus) di luar sambungan. Hasil pengujian menunjukkan perkuatan kolom bulat beton bertulang dengan metode jacketing/wrapping dengan satu lapis GFRP mampu meningkatkan daya dukung aksial sebesar 11,86% sampai dengan 15,25% dan daktilitas aksial sebesar 12,41 % sampai dengan 47,14%. Abstract: The paper presents an experimental investigation the effect of circular reinforced concrete short columns strengthening using Glass Fiber Reinforced Polymer (GFRP) wrap with variation of overlapping to failure behavior, axial capacity and axial ductility. Twenty one cylindrical concrete specimens with diameters of 150 mm, and 300 mm high were made and tested. Variations of overlapping in this research were 100%, 150%, 200%, 250% and 300 % from overlapping that calculation with GFRP ultimate tension and ultimate debonding strength. Compressive load was applied to the specimens until the specimens failure. Data that note when test were; failure behavior, maximum load and longitudinal strain for every 10 kN increasing load. GFRP with overlapping 100% and 150% failed by sliding (debonding) in overlapping zone, while GFRP with overlapping 200% until 300% failed by broken outside overlapping zone. The experimental results show that circular reinforced concrete columns strengthening by jacketing method/wrapping using one layer of GFRP sheet increasing axial capacity by 11,86% until 15,25% and axial ductility by 12,41% until 47,14%.
KUAT TEKAN DAN MODULUS ELASTISITAS BETON DENGAN PENAMBAHAN STYROFOAM (STYROCON) Dharma Giri, Ida Bagus; Sudarsana, I Ketut; Tutarani, Ni Made
Jurnal Ilmiah Teknik Sipil Vol. 12, No. 1 Januari 2008
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This experiment is aimed to know the value of compressive strength and elastic modulus of concrete by adding granular styrofoam and also relationship between compressive strength and elastic modulus of concrete by percentage increased granular styrofoam. Granular styrofoam is used by consideration it can reduce the weight of concrete but still has enough strength to arrest loads. The comparison of mixture is 1 : 2 : 3 (cement : sand : crush stone) by comparison of weight with water cement ratio is 0,50 and maximum size of aggregates are 25 mm. Variation of percentage increased granular styrofoam are 0%, 10%, 20%, 30%, 40% to volume of mixture. The range of diameter granular styrofoam are 3-10 mm, with volume of weight 22,89 kg/m3. The specimen for compression and elastic modulus test in cylindrical form by size 150 mm of diameter and 300 mm of height with amount 7 specimens for each percentage increased granular styrofoam where 5 specimens are read the change of length to get modulus of elasticity. The tests are done when specimens age 28 days. Experiment results show that compressive strength and elastic modulus decrease with increased percentage granular styrofoam which add to concrete mixture. The value of compressive strength by adding granular styrofoam 0%, 10%, 20%, 30%, 40% are 32,395 MPa, 24,144 MPa, 17,994 MPa, 13,411 MPa, 9,995 MPa. Decreased of elastic modulus by adding granular styrofoam 10%, 20%, 30%, 40% based on ASTM C 469 are 0,278%, 5,797%, 16,555%, and 32,553%, and based on slope of the stress-strain curve are 0,587%, 6,256%, 17,006%, and 32,838%.
PERILAKU RUNTUH BALOK BETON BERTULANG YANG DIPERKUAT DENGAN LAPIS GLASS FIBRE REINFORCED POLYMER (GFRP) Sudarsana, I Ketut; Rai Widiarsa, Ida Bagus
Jurnal Ilmiah Teknik Sipil Vol. 12, No. 1 Januari 2008
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This research was conducted to know the failure behavior and flexural strength of reinforced concrete (R/C) beam strengthened with GFRP sheet. The research used simple supported beams with dimension of 100x150x1100 mm. The beam resisted two concentrated loads at a distance of 300 mm from each support. On the beams were applied 3 conditions that were beam without addition of GFRP sheet; beam with addition of 1 layer GFRP sheet and beam with addition of 2 layers GFRP sheet. The GFRP sheets used in this research were made of woven roving glass fibre mixed with epoxy resin. The data collected in this research were crack load, ultimate load, crack pattern, crack width, deflection and failure behavior. Results of from this research indicated that addition of GFRP sheet decreased the length and width of the R/C beam crack. The addition of GFRP sheet improved flexural strength of R/C beam as well. The addition of 1 layer GFRP sheet increased the flexural strength by 10,8 %, with failure in flexure accompanied by breaking of the sheet. On the other hand, the addition of 2 layers GFRP sheet increased the flexural strength by 13,4 %, with failure in flexure accompanied by debonding of the sheet from concrete surface. This showed that the sheet did not work effectively.
KARAKTERISTIK BATU BATA TANPA PEMBAKARAN TERBUAT DARI ABU SEKAM PADI DAN SERBUK BATU TABAS Sudarsana, I Ketut; Made Budiwati, Ida Ayu; Angga Wijaya, Yohanes
Jurnal Ilmiah Teknik Sipil Vol. 15, No. 1 Januari 2011
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This research was conducted to determine the characteristics of the brick compressive strength and water absorption. The bricks are made by using waste rice husk ash and rock-tabas powder which are added to cement as a glue and mixed with clay and they are left dry without firing. A total of five kinds of mixtures were made with a proportion of total rice husk ash and rock-tabas powder of 30%, 60% of clay and cement as much as 10% mixed with weight ratio. Variations of composition of rice husk ash and rock-tabas powder were made using ratios of 0%: 30%, 7.5%: 22.5%; 15%: 15%, 22.5%: 7.5%, and 30%: 0 %. The samples used are in the form of cubes with a size of 6x6x6 cm. Six-cubes were made form each mixture where 3 of them were used for compressive strength test and the other 3 for water absorption test. Tests conducted at 14 and 28 days. The result showed that the highest compressive strength of bricks without firing was 22.90 kg/cm2 obtained from the mixture I with the percentage of rice husk ash and pulverized tabas of 30%:0% at 28 days, while the lowest water absorption is at 44.03% gained from bricks of mixture V in which the ratio between rice husk ash and rock-tabas powder was 0%:30% at 28 days.
EFEK PENAMBAHAN DINDING GESER ATAU PERIMETER BEAMS TERHADAP PERILAKU DINAMIS STRUKTUR PELAT DATAR EMPAT TINGKAT Sudarsana, I Ketut; Giri, Ida Bagus Dharma; Wiryadi, I Gede Gegiranang
Jurnal Ilmiah Teknik Sipil Jurnal Ilmiah Teknik Sipil, Vol. 18, No. 1, Januari 2014
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Flat plate structural system is a plate structural system that supported directly by columns without column heads or drop panels. The advantages of this system are distance between the floors can be shortened, faster construction, ease of architectural work and installation of Mechanical, Electrical and Plumbing Equipment (MEP). However, this system has a weakness on the join (connection of slab-column) that is too flexible and susceptible to punching shear failure especially when the existence of moment due to earthquake. This study investigates the changes on dynamic behaviors of flat plate structures when it is added lateral stiffeners such as shear walls or perimeter beams in terms of its natural period, base shear force, floor displacement, and a change on the forces of the structural elements. The structure of the building being simulated is regular structure consisting of 4 floors with 3 meter floor to floor space and 4 spans along X axis direction (Lx = 6 m) and 3 spans along Y axis direction (Ly = 5 m). The building is a hotel, which stands on medium soil in Bali Provice. Flat plate structures with additional of shear walls or perimeter beam are designed in accordance with the requirements of SNI 03-2847-2002. Analyses were performed in three dimensions (3D) using commercial software SAP2000 v15, where the three structure models have the same property namelyplate thickness, column dimensions, mass and material properties. Dynamic behaviorsare studied based on time history analysis (integration time step) according to the average acceleration method from Newmark with acceleration record of the El-Centro earthquake 1940. Analysis shows that addition of shear walls or perimeter beam causes the natural period of structure and horizontal displacement decrease, while the base shear force and structural rigidity increase. Moments, shear forces on columns and shear forces on the plate around the column decrease with the addition of shear walls. The addition of perimeter beam increases the moments and shear forces on first floor columns and shear forces on the plate around the column decrease dramatically on the edge columns