Handling of coal burning waste of thermal power plant in Lati, Berau district, East Kalimantan province, which is recommended by the department of environmental impact management is to dispose the coal ash into pools flowed water so that coal ash did not fly and cause air pollution. As known that coal ash waste is included hazardous and toxic waste, therefore managing it carefully is a necessity. Sediment or heap of coal ash in the sedimentation pond that is flowing with water is called Pond Ash. This study is conducted by utilizing the pond ash as a replacement material in the concrete mix. The effect of the use of pond ash as partial replacement of sand, fine aggregate in the concrete mix, is studied using cylindrical specimen with a diameter of 100 mm and a height of 200 mm. Specimens were made by taking the ratio of the percentage of pond ash of 0%, 5%, 10%, 15% and 20% of the mixture of concrete with the constant water cement ratio 0.49 which is based on the results of normal concrete mix design. The compressive strength test of concrete was conducted at ages 1, 3, 7, 14, 28 and 90 days. The test results of compressive strength of concrete obtained showed an increase in compressive strength in accordance with the addition of pond ash in the mix. The adding of pond ash in the mix affected the increasing in the compressive strength of concrete, and the optimum strength is obtained in the ratio of 17% pond ash, which increased to 26.08 MPa from 25.05 MPa for concrete with and without pond ash mixes respectively, or increased by 4.12%. This increase is not significant and cannot be used as a reference, however, by the results of this study it can be concluded that the pond ash waste can be utilized for the manufacture of concrete as a partial replacement of sand.

Pond ash concrete bond is expected to increase bond strength, because in previous studies pond ash concrete resulted in increased mechanical properties of concrete. Bond strength is the bonding mechanism between steel reinforcement and concrete in reinforced concrete construction as the main tool to transfer internal strength between reinforcement and concrete. In this study, a total of thirty-six cylinder concrete with a diameter of 15 cm and a height of 30 cm. Variations of the test parameters are three reinforcement diameters of 12 mm, 16 mm and 25 mm and two types of reinforcement namely plain reinforcement and deform reinforcement for normal concrete and pond ash concrete, using a 25 MPa normal concrete mix design and water cement ratio of 0.52. The results showed that the increase in bond strength on the plain reinforcement from 84.49 kg/cm2 to 91.33 kg/cm2 an increase of 8.09%, while for deform reinforcement there was in increase from 119.70 kg/cm2 in concrete normal to 131.32 kg/cm2 an increase of 9.71% in pond ash concrete. Split collapse occurs in deform reinforcement, whereas in plain reinforcement, slip collapse occurs.

The Segiri Sports Arena is an area that provides sports facilities for the people of Samarinda City and its surroundings. Various sports facilities are available, but as the city of Samarinda develops, the area has turned into a multifunctional area due to the activities carried out by the community. This transformation has caused the Segiri GOR area to look slum. In order to restore the main function and accommodate all these multifunctional activities with a better arrangement, as well as efforts to make a redesign that can become a landmark of the City of Samarinda, research is needed on the study of the redesign of the Segiri Samarinda GOR area with an approach to city landmarks. The parameters used are the landmarks and the characteristics of the sport building. This research would be useful for the government to improve and accommodate various functions of community needs for sports areas, and present new city landmarks for Samarinda City. This Samarinda City landmark brings elements of the distinctive character of the City of Samarinda in the form of the building.

Tulisan ini merupakan hasil analisis dalam mengevaluasi ulang perhitungan kapasitas struktur Gedung convention hall Putri Karang Melenu Tenggarong terhadap hasil perencanaan awal akibat adanya pengurangan kolom bagian tengah gedung untuk memperluas ruangan memenuhi fungsi ruang pertemuan.  Evaluasi dilakukan menggunakan bantuan software Struktur Analisis Program (SAP) dan pengecekan lapangan terhadap lendutan yang terjadi. Dari hasil evaluasi analisis diperoleh penggunaan material lebih sedikit/ekonomis, sedangkan pengamatan lendutan diperoleh hasil lebih kecil dari lendutan hasil analisis khusus akibat beban permanen atau beban mati. Kondisi ruangan menjadi luas dan lapang tanpa kolom di bagian tengah ruangan.Kata kunci: Redesign, Bangunan Gedung, Convention Hall, SAP

ABSTRACT Handling of coal burning waste of thermal power plant in Lati, Berau district, East Kalimantan province, which is recommended by the department of environmental impact management is to dispose the coal ash into pools flowed water so that coal ash did not fly and cause air pollution. Sediment or heap of coal ash in the sedimentation pond that is flowing with water is called Pond Ash. This study is conducted by utilizing the pond ash as a replacement material in the concrete mix. The effect of the use of pond ash as partial replacement of sand, fine aggregate in the concrete mix, is studied using cylindrical specimen with a diameter of 100 mm and a height of 200 mm. Specimens were made by taking the ratio of the percentage of pond ash of 0%, 5%, 10%, 15% and 20% of the mixture of concrete with the constant water cement ratio 0.49. The void test of concrete was soaked for 28 day, In theory, the more dense concrete mix so that the higher density so low porosity will produce large compressive strength, otherwise the greater the voids, the strength of concrete is getting smaller and weaker. But in this study the opposite occurs because the value of the absorption material pond ash is very high compared with the absorption of sand and crushed stone, if the fair value of void in the mix also increased a corresponding increase in the composition of its pond ash. Because the particles are very fine pond ash so as to fill the gaps between fine aggregate and coarse aggregate, making the concrete more dense although large void. Keywords : coal ash waste, pond ash, concrete, void concrete. ABSTRAK Penangangan limbah pembakaran batubara pada pembangkit listrik tenaga uap di Lati kabupaten Berau Kalimantan Timur yang direkomendasikan badan pengelola dampak lingkungan adalah dengan cara membuang abu batubara ke dalam kolam-kolam yang dialiri air agar abu batubara tidak terbang yang menimbulkan polusi udara. Endapan atau kumpulan abu batubara dalam kolam pengendap yang dialiri air dinamakan Pond Ash. Penelitian ini memanfaatkan pond ash untuk campuran beton, dengan menguji pengaruh penggunaan pond ash sebagai pengganti sebagian agregat halus pasir dalam campuran beton, diteliti menggunakan spesimen berbentuk silinder diameter 100 mm dan tinggi 200 mm. Spesimen dibuat dengan mengambil perbandingan prosentase pond ash sebesar 0%: 5%: 10%: 15% dan 20% terhadap campuran beton dengan faktor air semen konstan 0.49. Pengujian porositas dalam campuran beton dilakukan setelah beton direndam selama 28 hari. Secara teori, semakin padat campuran beton semakin tinggi tingkat kepadatan sehingga porositasnya rendah dapat menghasilkan kekuatan tekan yang besar, sebaliknya semakin besar porositas, kekuatan beton semakin kecil dan semakin lemah. Tetapi dalam penelitian ini terjadi kebalikannya karena nilai penyerapan bahan pond ash sangat tinggi dibanding dengan penyerapan bahan pasir dan batu pecah, wajar apabila nilai porositas dalam campuran juga meningkat sesuai peningkatan komposisi pond ash nya. Karena partikel pond ash sangat halus sehingga dapat mengisi celah-celah antara agregat halus dan agregat kasar, membuat beton semakin padat walau porositasnya besar. Kata Kunci : limbah abu batubara, pond ash, beton, porositas beton.