The construction of multi-stories buildings is increasing rapidly. In concrete construction, various studies and innovations have been carried out in order to obtain high strength concrete. The use of limestone either as a substitute for fine aggregate, as a substitute for coarse aggregate or as a substitute for fine aggregate and even coarse aggregate in a concrete mixture is still lacking. In South Sulawesi, large quantities of limestone are found in several regencies. Enrekang Regency is one with considerable limestone potential which is about 74.75 km2 or an estimated geological of 3.7 billion cubic meters. Most limestone is made into split stones that can be used as construction materials. Limestone can be processed into split or powder which can be used as a replacement for sand in concrete mixture. The results of the concrete at 28 days with a mixture of natural sand as fine aggregate and limestone split as coarse aggregate, w/c ratio of 0.20 produced a value of f’c = 59.26 MPa. ft = 4.51 MPa (0.61 √f’c), and fr = 7.18 MPa (0.93 √f’c). The average modulus of elasticity at 28 days with a mixture of limestone powder as fine aggregate and limestone split as coarse aggregate produced a value of Ec = 46960.25 MPa (6325 √f’c) with Poisson’s ratio υ = 0.3847.
Filler has an important role in the HRS-WC mixture besides aggregates and asphalt due to its functions to fill the void in the asphalt mixture so that it could produce more friction resistance and high interlocking aggregate. The use of filler in the mixture is limited in number because too much filler will lead to the stiffer and easily cracked mixture. On the contrary, the lower values could lead to the easily deformed and too flexible mixture. Previous researchers have studied the use of the waste of crude palm oil (CPO) ash as a filler. This research aims to study the performance of the HRS-WC mixture using CPO ash as a filler. The asphalt content used was 5.9%; 6.33%; 6.75%; 7.18% and 7.6%, while the proportion of CPO ash waste is 0%, 25%, 50%, 75% and 100%. The mixture gradation is made using a gap-graded and half gap-graded mixture. The results showed that the stability is higher when 25% of CPO ash proportion is used, but it is decreased again when the proportion is larger than 25%. The use of a small asphalt content will increase the value of VIM. The flow value decreases when 32% of CPO ash proportion is used and increases again over the use of 32%. The use of a large amount of CPO ash filler in the mixture will increase VMA. While the VFB will decrease if the larger amount of CPO ash is used. The immersion index of the mixture can still be maintained even when the use of CPO ash is increased. The use of CPO ash as a substitute for filler in the HRS mixture - WC must be balanced with the increasing of asphalt mixture.
Durability is the ability of asphalt concrete to accept repetition of traffic loads, friction, and weather and climate wear, while permeability is the ability of pavement surfaces to hold water seepage into pavement. Besides, the pore volume in the mixture is one of the most important AC-WC characteristics which are related to the level of water impermeability in the pavement layers. The purposes of this study is to investigates the effect of adding coconut fibers by 0%, 0.5%, 1%, 1.5% and 2% on durability and permeability the surface layer of Laston BC. The results obtained are the stability of the asphalt mixture in accepting the load without changing the plastic shape and following the trend of the 2nd order polynomial line. VIM values tend to rise then decrease until 48 hours immersion. It is found that the use of coconut fibers improved the impermeability properties of the surface layer of Laston BC. The value of mixed flow is influenced by the addition of coconut fibers, where if the fibers increase to 1%, then the flow will decrease. The durability value due to the addition of 1% and 1.5% coconut fibers can only be tolerated at the submergence limit of Laston BC for 30 hours while the addition of coconut fibers from 0% to 2% Laston BC can only submerged for 12 hours. The permeability values of the mixture decreases by 0.51 cm/sec for each addition of 0.5% coconut fibers.
Setiap tahunnya jumlah limbah terus menerus bertambah, salah satunya limbah abu marmer, jumlah limbah akan terus bertambah baik dalam industri konstruksi, ekstraktif, fasilitatif dan lainnya. Tujuan dari penelitian ini untuk mengetahui nilai kuat tekan, kuat tarik belah dan modulus elastisitas dengan penelitian yang dilakukan di Laboratorium Struktur dan Bahan Universitas Kristen Indonesia Paulus Makassar. Benda uji yang digunakan yaitu silinder dengan diameter 150mm dan tinggi 300mm. Hasil pengujian kuat tekan dengan penambahan abu marmer 0% dengan fly ash 10% mengalami peningkatan sebesar 4,930% dari kuat tekan rencana, juga pada penambahan abu marmer 8% dengan fly ash 10% mengalami peningkatan sebesar 1,533%. Namun, pada penambahan abu marmer 12% dengan fly ash 10%, terjadi penurunan sebesar 9,035% dari nilai kuat tekan rencana sebesar 25 MPa. Hasil pengujian kuat tarik belah (ft) didapatkan nilai kuat tarik belah sebesar 2,713 MPa, 2,642 MPa dan 2,477 MPa. Untuk hasil pengujian Modulus Elastisitas (E) didapatkan nilai dengan penambahan abu marmer 0% dengan fly ash 10%, abu marmer 8% dengan fly ash 10% dan abu marmer 12% dengan fly ash 10%, sebesar 7979,762 MPa, 7597,352 MPa dan 7451,366 MPa. dari hasil penelitian dapat disimpulkan bahwa penambahan fly ash dengan variasi 10% masih mampu meningkatkan nilai kuat tekan, kuat tarik belah dan modulus elastisitas. Namun untuk penambahan abu marmer lebih dari 8% dapat menurunkan nilai kuat tekan, kuat tarik belah dan modulus elastisitas.
Bottom ash (abu dasar) adalah sisa pembakaran batu bara di Indonesia di kategorikan sebagai limbah (B3). Kandungan logam berat dalam limbah B3 menyebabkan pencemaran lingkungan. Bottom ash melimpah dan kurang dimanfaakan. Oleh karena itu berbagai inovasi dilakukan peneliti agar penggunaan kontruksi beton layak digunakan terhadap pengaruh hujan asam serta pengelolaan bottom ash sebagai material konstruksi beton. Pada penelitian ini persentase substitusi bottom ash agregat halus sebanyak 0%, 25%, 35% dapat digunakan untuk campuran beton dengan perendaman asam sulfat pH-4. Dengan benda uji yang digunakan berukuran 15 cm x 30 cm dan 60 cm x 15 cm x 15 cm sebanyak 45 sampel, menggunakan metode American Concrete Institute (ACI). Pengujian tersebut berupa pengujian kuat tekan. kuat tarik belah dan kuat lentur beton dengan mutu rencana sebesar 30 MPa. Pada umur 28 hari didapatkan nilai kuat tekan sebesar 32,727 Mpa, 33,859 Mpa, 36,782 Mpa. Beton dengan substitusi bottom ash sebagai agregat halus dengan variasi 0%, 25% dan 35% mengalami peningkatan kekuatan seiring bertambahnya persentase substitusi bottom ash dimana semakin tinggi persentase substitusi bottom ash maka kekuatan beton semakin tinggi, sehingga dapat dikatakan bahwa persentase substitusi bottom ash berbanding lurus dengan kekuatan beton.
Abstract. This study is carried out to evaluate the potential of three hybrid T-beams with web openings theoretical shear stresses distribution. The shear stresses at the opening edges were plotted at the working stage, yielding stage and collapse stage for these three tested beams. The available experimental results from the previous research was compared to the finite element results as well as the developed analytical. The shear stress distribution at the middle of the top and bottom chords of the opening in pure bending region are zero. At the upper and lower corners of the opening occurs the maximum shear stresses. The maximum shear stress occurs at the right lower corner chord at the high moment edge and at the left upper corner chord at the low moment edge in beams with openings at high shear and high flexural -shear region. Furthermore, an extensive parametric study is performed on these beams to find the distributing ratio of the shear force between the opening chords. The shear force at an opening in hybrid R/C T-beam is carried by the top and bottom chords of the opening according to the area -moment of inertia root ratio with the correction factor 0.70.
Curved bridges have become a major component of highway systems in recent years. Elevated freeways and multi level interchange are very common in densely populated areas and could hardly be constructed without curved bridges. Usually, these bridges are of cellular cross section so that the high torsional moment due to curvature can be resisted economically. To date, methods of analysis and design have been very approximate, but because of the large number of curved bridges being constructed everywhere, refined methods of analysis are desirable. In this paper, the main geometric parameters of curved bridges are studied. The finite strip method of analysis applied to folded plate structures as a box girder, for which a general computer program was written. This method of analysis is restricted to structures simply supported along their straight radial edges. Finally, on the basis of this refined analytical method, the behaviour of curved box girder bridges is studied. In particular, wheel load distribution characteristics are investigated especially with respect to the load position of the bridges.
Salah satu model perencanaan struktur yang dapat dipakai untuk mengefisienkan struktur gedung ialah dengan menambahkan balok anak. Berdasarkan asumsi tersebut maka tulisan ini dibuat untuk menganalisis pengaruh penempatan balok anak pada struktur lantai gedung untuk mengetahui besarnya efisiensi yang terjadi terhadap tebal pelat dan material beton bertulang yang digunakan. Pada kasus perencanaan gedung Toko Satu Sama di Jl. Perintis Kemerdekaan Kota Makassar denah lantai diberi satu balok anak pada arah-x dan menghasilkan tebal pelat 150 mm. Denah lantai tersebut direncanakan ulang dengan membuat denah lantai tanpa balok anak, denah lantai dengan balok anak arah-y dan denah lantai dengan balok anak arah-x dan y. Momen lentur yang terjadi pada pelat lantai dihitung menggunakan metode PBI 1971, namun dengan tetap mempertimbangkan ketentuan terbaru dalam SNI 2847, 2019. Hasil perhitungan menunjukkan bahwa denah lantai dengan pola penempatan balok anak arah-x dan y (h = 120 mm) dapat mengefisienkan pelat sebesar 20 % dari tebal pelat dengan pola penempatan balok anak arah-x. Sejalan dengan itu kebutuhan beton pun dapat diefisienkan sebesar 15,359 % (12,284 m3). Sekalipun memiliki kebutuhan tulangan yang lebih banyak, pola penempatan balok anak arah-x dan y merupakan pola yang paling efisien.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.