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KAJIAN SIFAT MEKANIK BETON RINGAN DENGAN PENGGUNAAN POLYSTYRENE SEBAGAI BAHAN SUBSTITUSI AGREGAT HALUS Siamet Widodo
Inersia : Jurnal Teknik Sipil dan Arsitektur Vol 1, No 1 (2005): Maret
Publisher : Universitas Negeri Yogyakarta

ABSTRACTLightweight concrete offers some advantages in reinforced concreteconstruction. It can be produced by replacing the normal aggregate (sand andgravel) with lightweight aggregate, either partially or fully, depending upon therequirements of density and strength. The present study covers the use ofexpanded polystyrene as fine lightweight aggregate in order to produce structurallightweight aggregate.These mixes were designed by using several variances of polystyrenevolume percentage by total fine aggregate. The substitution was done with 0%,25%, 500/0, 750/0 and 1000/0 by total volume of fine aggregate, with 0,50 watercement ratio. The Properties of hardened concrete namely compressive strength,splitting tensile strength and flexural strength were tested in 28 days of curingperiod.It is observed that polystyrene lightweight concrete has sufficient strengthto be accepted as structural lightweight concrete in 25~'O substitution by totalvolume of fine aggregate, with 17,35 MPa of compressive strength, but thecompressive strength will always decrease depending on the increasing ofpolystyrene percentage. The splitting tensile strength of polystyrene lightweightaggregate approximately 14%--18% of its compressive strength,for the normalconcrete it is nearly 10% of 28 days compressive strength. The flexural strengthwas ranging between 20%-30% of its compressive strength, higher than normalconcrete that nearly 15% of its compressive strength.Keywords: lightweight concrete, mechanical properties, polystyrene

PENGEMBANGAN MEDIA PEMBELAJARAN VIDEO ANIMASI UNTUK MATA PELAJARAN MEKANIKA TEKNIK KELAS X DESAIN PEMODELAN DAN INFORMASI BANGUNAN DI SMK N 2 YOGYAKARTA Tiara Titania; Slamet Widodo
Jurnal Pendidikan Teknik Sipil Vol 2, No 2 (2020): November
Publisher : Universitas Negeri Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21831/jpts.v2i2.36343

Penelitian ini dilaksanakan untuk mengembangkan media pembelajaran animasi untuk mekanika teknik berdasarkan kurikulum SMK 2013 Revisi 2016 yang layak dan dapat menjadi alternatif sumber belajar siswa. Penelitian ini termasuk penelitian dan pengembangan atau Research and Development (RD) dengan model penelitian 4D (Define, Design, Development and Disseminate) dan disesuaikan dengan kebutuhan. Pengumpulan data menggunakan angket ahli dan kuisioner didukung dengan kegiatan observasi. Angket ahli diberikan kepada ahli materi, ahli media dan angket kuisioner diberikan untuk pengguna (guru pengampu Mekanika Teknik SMK N 2 Yogyakarta). Hasil penelitian ini berupa media pembelajaran video animasi untuk mata pelajaran Mekanika Teknik dengan hasil setiap tahap sebagai berikut: (1) Hasil tahap define adalah analisis kebutuhan awal yaitu siswa belum mengetahui konsep dari pemodelan struktur, cara belajar setiap siswa yang berbeda dan media yang digunakan kurang bervariasi. Analisis konsep menghasilkan konsep tampilan media secara umum dan analisis tugas menghasilkan penetapan kompetensi dasar yang menyesuaikan dengan analisis kebutuhan awal untuk kemudian dirumuskan tujuan pembelajarannya; (2) Hasil tahap design adalah susunan materi berdasarkan kompetensi dasar dan indikator yang telah ditetapkan. Hasil akhir media berformat .exe terdiri dari animasi, video dan teks; (3) Hasil tahap development berupa nilai dari validasi ahli dan calon pengguna sebagai berikut: a) penilaian ahli materi pada media pembelajaran animasi mekanika teknik mendapatkan skor 68 dan persentase 100% dan dinyatakan bahwa media sangat layak, b) penilaian ahli media pada animasi media pembelajaran mekanika teknik mendapatkan skor 84 dan persentase 91,6% dan dinyatakan bahwa media sangat layak, dan c) penilaian dari uji coba calon pengguna pada media pembelajaran video animasi mekanika teknik mendapatkan rata-rata skor 39,5 dan persentase 76,3% dan dinyatakan bahwa media layak digunakan.

Experimental test on polyended polysterene addition as a partial substitute of fine aggregate Bagas Habibilah; Slamet Widodo
Journal of Engineering and Applied Technology Vol 3, No 1 (2022): (March)
Publisher : Faculty of Engineering, Universitas Negeri Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21831/jeatech.v3i1.42550

This research aimed to determine the values of specific gravity, compressive strength, and modulus of elasticity by replacing some fine aggregate with styrofoam (Polyended Polysterene). This research was done by using experimental methods in the Building Materials Laboratory, Department of Civil and Planning Engineering Education, Universitas Negeri Yogyakarta. The percentage of Polyended Polysterene addition as a partial substitute of fine aggregate was done at 0%, 15%, 30%, and 45%. Each percentage of Polyended Polysterene addition as a partial replacement of fine aggregate consisted of 3 cylindrical concrete specimens with a diameter of 150 mm and a height of 300 mm. Specific gravity testing of concrete was conducted 24 hours after concrete casting. The compressive strength and modulus of elasticity of the concrete were tested at 91 days. The results of the research showed that: (1) the specific gravity values of concrete decreased linearly with the value of 2345,83 kg/m3, 2242,45 kg/m3, 2154,88 kg/m3, and 2040,79 kg/m3, (2) the compressive strength values of concrete are 28,55 MPa, 18,52 MPa, 20,26 MPa, and 15,3 MPa, and (3) the modulus of elasticity values of concrete is 15969,61 MPa, 13395,58 MPa, 14994,2 MPa, dan 14479,03 MPa. From the test results, the optimal value at a percentage of 30% with a specific gravity value of concrete close to the lightweight concrete requirements and a compressive strength value meets the structural requirements.

The Ultrasonic Pulse Velocity and Lagrangian Approaches to Predict the Effective Thickness and Homogeneity of the Sandwich Panel Faqih Ma'arif; Slamet Widodo; Maris Setyo Nugroho; Mohamad Tafrikan; Zhengguo Gao
U Karst Vol 6, No 2 (2022): NOVEMBER
Publisher : Kadiri University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30737/ukarst.v6i2.3545

Non-destructive testing can be applied to various things, including sandwich panels. Sandwich panels made of EPS are greatly affected by the mixing process. Bad mixing can affect the level of homogeneity and reduce quality. In addition, the improper thickness of layers and cores can result in wall damage. For this reason, carrying out a non-destructive test on the sandwich panel is necessary. This study aims to determine the homogeneity of the material and predict the dimensions of the EPS core and layer. Experimental testing was conducted using Ultrasonic Pulse Velocity (direct method) with 90 points. The test object consisted of six sandwich panel walls with three variants, each with dimensions and layer thickness of 15 mm, 20 mm, and 25 mm, respectively, while the core layer size was 70 mm, 80 mm, and 90 mm, respectively. The test results were analyzed on travel time and wave velocity using a statistical analysis approach including covariance, Kolmogorov-Smirnov, ANOVA, t-test, and Lagrangian. The analysis results show that the mixture's homogeneity can be determined based on the ultrasonic pulse velocity. The proposed Lagrange analysis can reveal the behavior of the propagation speed. Based on the results of the Lagrange approach, the highest speed is obtained at a thickness of 80 with a maximum speed of 2.395 km/s. The results of this study contribute to the non-destructive test procedure, especially in determining homogeneity and the dimensions of the effective thickness of the structural walls (cores and layers) that have been installed in the field quickly, cheaply, accurately, and briefly.

Correlation of Ultrasonic Pulse Velocity with Porosity and Compressive Strength of Mortar with Limestone for Building Quality Assessment Slamet Widodo; Faqih Ma'arif; Maris Setyo Nugroho; Hidayat Mahardika
U Karst Vol 6, No 2 (2022): NOVEMBER
Publisher : Kadiri University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30737/ukarst.v6i2.3508

Mortar is used for bonding bricks, filling gaps in masonry, and as a plaster for strengthening and smoothing wall surfaces in finishing works. Poor quality of mortar can cause cracks in the walls which are identified after the building is completed. Assessment of a building is essential to determine its quality. Non-destructive testing is widely chosen because it will not directly affect the physical building condition. However, there still needs to achieve a good fit equation that can be used to estimate mortar quality using non-destructive testing. This research aimed to propose a formula to predict the mortar quality using an ultrasonic pulse velocity (UPV) test with porosity and compressive strength in the mortar with limestone. Variations in adding the lime powder to the mortar mix are 20%, 30%, 40%, and 55%. It was divided into M, S, N, and O types. The mortar cubes were prepared based on ASTM C-1329 and ASTM C-270. The specimens were then evaluated with UPV, porosity, and compressive strength test using three samples for each test. Equations for the relationship between UPV and porosity and compressive strength can be derived from these tests. The results showed that the value of the ultrasonic pulse speed is directly proportional to the compressive strength of the mortar, which fits the equation y = 0.0542e0.0015x, and is inversely proportional to the porosity, showing the equation y = 108.57e-6E-04x. The results of this study can be used to assess the quality of new construction works and existing buildings.

Development of Eco-friendly Self-compacting Concrete Using Fly Ash and Waste Polyethylene Terephthalate Bottle Fiber Slamet Widodo; Rifki Alfirahma; Alamsyah Prawiranegara; M Fajar Amir; Aniswara Dewi
Civil Engineering Journal Vol 9, No 2 (2023): February
Publisher : Salehan Institute of Higher Education

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.28991/CEJ-2023-09-02-014

This study aims to utilize fly ash and waste PET bottles for producing more sustainable self-compacting concrete (SCC) with better mechanical strength. Fly ash is utilized as a supplementary cement material and waste PET bottles as fiber reinforcement to improve its flexural strength and achieve the targeted compressive strength. The experimental works were conducted on eight variations using 80 specimens, divided into two main groups of partial cement replacement using 0% and 15% fly ash by weight. The two variants are added with PET fiber based on the volume fractions of 0%, 0.25%, 0.50%, and 0.75%. Fresh concrete was tested using the slump flow method (T50) and the Visual Stability Index (VSI) based on ASTM 1611. The hardened concrete tests are conducted after 56 days and include testing the concrete's compressive strength, flexural strength, and ultrasonic pulse velocity. Test results showed that the presence of PET fiber in the SCC mix decreased its flowability. However, when added up to 0.75%, the mixes still meet the flowability requirements of fresh-state SCC. PET fiber addition tends to reduce the compressive strength, whereas the reduction in compressive strength of SCC with PET fiber without fly ash is insignificant. However, in SCC that uses fly ash, the addition of PET fiber causes a significant decrease in its compressive strength. Adding PET fiber into SCC mixes can increase flexural strength, both for the two variants: SCC without fly ash and SCC with fly ash. It can be concluded that PET waste fiber with an aspect ratio of 40 can be added up to 0.5% for SCC without fly ash and up to 0.25% by volume fraction for SCC with fly ash addition. The ultrasonic pulse velocity test results have an excellent tendency to predict the concrete's compressive and flexural strengths. Therefore, the UPV test can be applied for the non-destructive test evaluation of PET fiber-reinforced SCC. Doi: 10.28991/CEJ-2023-09-02-014 Full Text: PDF

Correlation of Ultrasonic Pulse Velocity with Porosity and Compressive Strength of Mortar with Limestone for Building Quality Assessment Slamet Widodo; Faqih Ma'arif; Maris Setyo Nugroho; Hidayat Mahardika
U Karst Vol. 6 No. 2 (2022): NOVEMBER
Publisher : Kadiri University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30737/ukarst.v6i2.3508

Mortar is used for bonding bricks, filling gaps in masonry, and as a plaster for strengthening and smoothing wall surfaces in finishing works.Â Poor quality of mortar can cause cracks in the walls which are identified after the building is completed. Assessment of a building is essential to determine its quality. Non-destructive testing is widely chosen because it will not directly affect the physical building condition. However, there still needs to achieve a good fit equation that can be used to estimate mortar quality using non-destructive testing. This research aimed to propose a formula to predict the mortar quality using an ultrasonic pulse velocity (UPV) test with porosity and compressive strength in the mortar with limestone. Variations in adding the lime powder to the mortar mix are 20%, 30%, 40%, and 55%. It was divided into M, S, N, and O types. The mortar cubes were prepared based on ASTM C-1329 and ASTM C-270. The specimens were then evaluated with UPV, porosity, and compressive strength test using three samples for each test. Equations for the relationship between UPV and porosity and compressive strength can be derived from these tests. The results showed that the value of the ultrasonic pulse speed is directly proportional to the compressive strength of the mortar, which fits the equation y = 0.0542e0.0015x, and is inversely proportional to the porosity, showing the equation y = 108.57e-6E-04x. The results of this study can be used to assess the quality of new construction works and existing buildings.

The Ultrasonic Pulse Velocity and Lagrangian Approaches to Predict the Effective Thickness and Homogeneity of the Sandwich Panel Faqih Ma'arif; Slamet Widodo; Maris Setyo Nugroho; Mohamad Tafrikan; Zhengguo Gao
U Karst Vol. 6 No. 2 (2022): NOVEMBER
Publisher : Kadiri University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30737/ukarst.v6i2.3545

Non-destructive testing can be applied to various things, including sandwich panels. Sandwich panels made of EPS are greatly affected by the mixing process. Bad mixing can affect the level of homogeneity and reduce quality. In addition, the improper thickness of layers and cores can result in wall damage. For this reason, carrying out a non-destructive test on the sandwich panel is necessary. This study aims to determine the homogeneity of the material and predict the dimensions of the EPS core and layer. Experimental testing was conducted using Ultrasonic Pulse Velocity (direct method) with 90 points. The test object consisted of six sandwich panel walls with three variants, each with dimensions and layer thickness of 15 mm, 20 mm, and 25 mm, respectively, while the core layer size was 70 mm, 80 mm, and 90 mm, respectively. The test results were analyzed on travel time and wave velocity using a statistical analysis approach including covariance, Kolmogorov-Smirnov, ANOVA, t-test, and Lagrangian. The analysis results show that the mixture's homogeneity can be determined based on the ultrasonic pulse velocity. The proposed Lagrange analysis can reveal the behavior of the propagation speed. Based on the results of the Lagrange approach, the highest speed is obtained at a thickness of 80 with a maximum speed of 2.395 km/s. The results of this study contribute to the non-destructive test procedure, especially in determining homogeneity and the dimensions of the effective thickness of the structural walls (cores and layers) that have been installed in the field quickly, cheaply, accurately, and briefly.

Comparative study of sinus earthquake forces and ground motion on structure behavioral response using linear time history analysis method Suryatama Ageng Pamuji; Slamet Widodo; Maris Setyo Nugroho; Faqih Ma`arif; Ahmed Wasiu Akande
Journal of Engineering and Applied Technology Vol 4, No 1 (2023): (March)
Publisher : Faculty of Engineering, Universitas Negeri Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21831/jeatech.v4i1.58666

This study aimed to calculate the design earthquake with a harmonic sine wave approach at a frequency of 1.5 Hz; 2.5 Hz; 3.5 Hz; 4;5 Hz, as well as Loma Prieta, Northridge, and Kobe ground motion. In addition, a structural response review was also carried out based on a comparison of the effects of the ground motion and sine wave earthquake forces. This study used an experimental method of modelling an apartment building with a scale of 1: 50. The case study was located in Mantrijeron, Yogyakarta, which has a seismic category in the medium-size class. The analysis phase began with material definition, element dimension estimation, modelling by analysis software, loading estimation, structural analysis, and comparison of structural responses based on the deviation. The results indicate that the building model could withstand dynamic loads from harmonic waves up to a frequency of 5.5 Hz for one minute of vibration. The most significant deviation is shown at a frequency of 4.5 Hz with an x-axis direction of 0.110 and a y-direction of 0.160. The structural response resulting from ground motion loading shows that the highest deviation occurred due to the influence of the Kobe earthquake, with a deviation of 0.063 in the x-axis direction and 0.054 in the y-axis direction. Based on these results, the effect of harmonic sine waves is greater than the ground motion loading on the response of the building structure, so it is used as an experimental loading through a vibrating table with the actual residual deviation results showing a value of 0.9 mm in the y-axis direction. The difference in structural response results could be caused by the supports and connections modelling in planning through analysis software which could not precisely represent the actual implementation of the building model.

Discrete Element Method Approach to Simulate Cracks in Four-Point Flexural Test Faqih Ma arif; Slamet Widodo; Maris Setyo Nugroho; Zhengguo Gao
UKaRsT Vol. 7 No. 1 (2023): APRIL
Publisher : Kadiri University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30737/ukarst.v7i1.4401

Concrete is a material that is widely used in construction. Concrete research efforts are ongoing and through a series of experimental tests. On the other hand, experimental tests require a lot of money, take a long time, and create waste. Several studies have revealed that numerical testing can accurately test concrete to fractures. However, modeling for the four-point load flexure test pattern is still not widely discussed. This study aimed to model the four-point flexural test of concrete using the discrete element method (DEM) approach. Sieve gradation was performed to determine particle size, and flexure testing was performed to calibrate the DEM model. DEM flexure testing was made using Yet Another Dynamic Engine (YADE) software with ASTM D6272 reference and beam dimensions 105 x 105 x 535 mm. The cohesive contact model with spherical particles is used, and the algorithm developed modifies the faceted sphere of interaction. The study results revealed that DEM can simulate crack behavior in flexural testing of unreinforced concrete. The DEM results show only a 2.13% difference in the experimental results of the flexural strength test. Meanwhile, crack behavior can be observed directly in the DEM simulation. The results of this study can be used to predict the failure pattern of the flexural test structure and to design the right proportion of the mixture to match the desired flexural strength. So that material efficiency and concrete flexure testing time can be achieved.

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