COMPARISON OF ULTRASONIC PULSE VELOCITY TEST RESULTS WITH AND WITHOUT USING TRANSDUCER STABILIZER

Some research on the Ultrasonic Pulse Velocity (UPV) test has not covered much about the problems encountered during the data collection process. Based on experience using UPV test equipment, it is known that instability occurs in reading the test results. This is caused by the inability of the operator, in maintaining the stability of the transducer both in its position and pressure, especially in the measurement with the overhead position. Therefore, in this study a tool was made to make the transducer stable in the test position. Comparison of measurement results shows that, the uncertainty of wave velocity measurement decreases from the range of 4% -17% to 0.2% -0.4%. Meanwhile, the uncertainty of measurement of wave travel time decreased from the range of 0.8% -14% to 0.1% -0.4%. This can be interpreted that, the level of accuracy of measurements using a transducer stabilizer is 99.6% -99.9%. Thus, the use of transducer stabilizers is believed to be able to improve measurement accuracy

Modifikasi Karakteristik Kuat Tarik pada Komposit Film Poli(Vinil Pirolidon) dan Karagenan Melalui Pembentukan Komposit Karbon Nano Dot

Polimer merupakan material yang banyak dijadikan komposit sekarang ini. Teknologi nano dapat berperan sebagai agen komposit yang lebih baik dari pada agen komposit konvensional. C-dot yang merupakan material nano yang dikompositkan dengan polimer alam dan sintetik dengan model berturut-turut karagenan dan poli(vinilpirolidon) (PVP). Pada penelitian ini C-dot disintesis dari asam sitrat dan urea dengan iradiasi gelombang mikro, kemudian produk dimurnikan dan dikarakterisasi. Karagenan diekstraksi dari rumput laut Eucheuma cottonii. Selanjutnya polimer dan C-dot dikompositkan dengan metode Gel-Casting. Sintesis C-dot dari asam sitrat dan urea menghasilkan larutan berwarna hitam yang menandakan C-dot terbentuk, terdapat absorbsi di panjang gelombang 340 nm pada daerah UV yang membuktikan C-dot berhasil disintesis karena serapan tersebut tidak ditemukan pada bahan baku. C-dot yang disintesis memiliki ukuran partikel 90,61 nm dan indeks polidispersitas (PI) sebesar 0,0396. Komposit C-dot dengan polimer dapat meningkatkan kuat tarik dan modulus elastisitas film polimer. Konsentrasi optimum C-dot sebagai pengisi (filler) untuk PVP sebesar 0,7% b/b dan Karagenan 1.5% b/b. C-dot dapat berperan sebagai pengisi (filler) dalam kuat tarik pada film polimer. Penambahan C-dot pada film polimer sintetik maupun alam dapat meningkatkan sifat mekanik dari film polimer dan tidak memberikan hasil yang berbeda

OPTIMALISASI PEMANFAATAN LIMBAH ABUTA (ABU SEKAM PADI, DAN SERBUK BATA) SEBAGAI SUBTITUSI SEMEN PADA CAMPURAN BETON RAMAH LINGKUNGAN

Construction prioritizes the strength of concrete without thinking about the negative impact on the environment. The cement industry is estimated to contribute 5-7% of CO2 gas emissions in the world. On the other hand, Indonesia is also faced with environmental problems caused by various industrial waste. From this problem an innovation emerged, namely ABUTA (husk ash and brick ash). The aim of this innovation is to create a concrete innovation using Abuta Waste (Rice Husk Ash, and Brick Powder). For the manufacture of economical, environmentally friendly concrete to reduce the negative impacts caused by excessive use of cement and reduce industrial waste in Indonesia. In writing this proposal the author used the experimental writing method and data collection method. The concrete innovation applied is concrete with a mixture of variations in the composition of rice husk ash powder and red brick powder of 10% of the cement composition in conventional concrete so that it is more economical and environmentally friendly. In this study, the ACI (American Concrete Institute) mix design method was used with the required design quality of 30 MPa. It is hoped that this innovation can become an environmentally friendly concrete innovation to reduce the negative impacts of excessive cement use and reduce industrial waste in Indonesia. Based on the mix design, the proportion of ash mixture (rice husk ash and brick powder) is 1:1. Meanwhile, the ratio of the amount of ash mixture to cement is 10%: 90%. The compressive strength of concrete with a 0% Abuta mix variation (7 days old) was 19.5, while the concrete innovation with a 10% Abuta mix variation (7 days old) was 15.70 Mpa. This means that the 10% mixture reduces the compressive strength value by 46.28% below the 0% abuta mixture variation. Using a mixture of 10% ash (rice husk ash and brick powder) in innovative concrete can reduce production costs by IDR. 76,700/m³. Based on the materials obtained in this manufacture, it can be concluded that to obtain optimal compressive strength, better quality materials are needed. The application of concrete can be applied in casting work floors and non-structural construction work such as buildings that require general load power such as housing, sculpture, home interiors and others

Peningkatan Pengetahuan Serta Keterampilan Penulangan dan Pengecoran Pada Masyarakat Candi Kuning, Tabanan, Bali

Reinforced concrete is the most widely used structure compared to steel or wood. Reinforced concrete is generally very easy to work with. The material is very easy to get. It\u27s so easy, it\u27s often done by workers who don\u27t have knowledge and skills about concrete structures. This condition is exacerbated by building owners who do not pay attention to the details of reinforced concrete structures. The owner does not want to pay for the planning consultant or supervisor. The combination of these causes the condition of the building to be not in a safe condition even though in reality there are still many buildings that are being worked on haphazardly and are still in good condition. In the rules of Civil Engineering where safety is the main thing, the conditions above must be corrected. One of the efforts of the academic community to improve this situation is to implement a Community Service Program (PKM) in the form of Technical Guidance (Bimtek) for construction workers. This Bimtek is filled with the provision of theory and practice. The theory presented is knowledge about reinforcement and concrete constituent materials. While the practice consists of working on reinforcement: cutting, bending and assembling reinforcement. For concrete practice consists of mixing and casting concrete. From this Bimtek, the construction workers understand and able to do reinforcement, mix and pour concrete properly. It is hoped that after attending this Bimtek, the construction workers will be able to apply their knowledge and skills to the projects they are working on in order to obtain a good reinforced concrete structure. In its implementation, this Bimtek received a good reception from the Perbekel and the community. In his speech, the Perbekel of Candi Kuning Village hoped that the masons who had attended this Bimtek would become pioneers of correct concrete structure work, be able to increase competitiveness and get increased wages. Through the representatives of the participants, they expressed their gratitude for the knowledge taught and hoped that similar activities could be carried out again.Reinforced concrete is the most widely used structure compared to steel or wood. Reinforced concrete is generally very easy to work with. This condition is exacerbated by building owners who do not pay attention to the details of reinforced concrete structures. The combination of these causes the condition of the building to be not in a safe condition even though in reality there are still many buildings that are being worked on haphazardly and are still in good condition. In the rules of Civil Engineering where safety is the main thing, the conditions above must be corrected. One of the efforts of the academic community to improve this situation is to implement a community service program in the form of technical guidance for construction workers. From this activity, the construction workers understand and able to do reinforcement, mix and pour concrete properly. It is hoped that after attending this activity, the construction workers will be able to apply their knowledge and skills to the projects they work at in order to obtain a good reinforced concrete structure. In its implementation, this activity received a good reception from the community leaders. In his speech, the Candi Kuning Village leader hoped that the masons who had attended this activity would become pioneers of correct concrete structure work, be able to increase competitiveness and get increased wages. Through the representatives of the participants, they expressed their gratitude for the knowledge taught and hoped that similar activities could be carried out in the future. Keywords- reinforced concrete structure, technical guidance, reinforcement, concrete mixing andcasting. Beton bertulang merupakan struktur yang paling banyak digunakan dibandingkan baja maupun kayu. Beton bertulang secara umum sangat mudah dikerjakan. Terkadang pemilik bangunan yang tidak mengindahkan detail dari struktur beton bertulang. Kombinasi dari hal tersebut menyebabkan kondisi gedung tidak dalam keadaan aman walaupun pada kenyataannya masih banyak gedung yang dikerjakan serampangan hingga kini masih dalam keadaan baik. Pada kaidah ilmu Teknik Sipil di mana keamanan adalah hal yang utama maka kondisi di atas harus diperbaiki. Salah satu upaya civitas akademika untuk memperbaiki keadaan itu adalah dengan melaksanakan program Pengabdian Kepada Masyarakat (PKM) berupa Bimbingan Teknis (Bimtek) kepada para pekerja konstruksi. Hasil dari bimtek ini para tukang menjadi mengerti, memahami dan dapat mengerjakan penulangan, mencampur dan mengecor beton dengan benar. Diharapkan setelah bimtek ini para tukang dapat mengaplikasikan pengetahuan dan keterampilannya pada proyek-proyek yang dikerjakannya sehingga diperoleh struktur beton bertulangan yang baik. Pada pelaksanaannya, bimtek ini mendapat sambutan yang baik dari perbekel dan masyarakat. Perbekel Desa Candi Kuning dalam sambutannya mengharapkan para tukang yang telah mengikuti Bimtek ini menjadi pionir pekerjaan struktur beton yang benar, mampu meningkatkan daya saing dan mendapatkan peningkatan upah kerja. Melalui perwakilan peserta disampaikan rasa terima kasih atas pengetahuan yang diajarkan dan harapan agar kegiatan serupa dapat dilaksanakan kembali. Kata kunci- struktur beton bertulang, bimbingan teknis, penulangan, pencampuran dan pengecoran beton