Pemberdayaan Masyarakat dalam Pemanfaatan Botol Bekas sebagai Biofilter Septic Tank di Desa Pecuk, Demak

Desa Pecuk merupakan salah satu desa di Kecamatan Mijen Kabupaten Demak yang  saat ini tidak luput mengalami permasalahan sampah terutama sampah plastik yang semakin meningkat dan belum dikelola dengan baik. Selain permasalahan sampah, Desa Pecuk berdasarkan data yang ada juga dihadapkan pada pemrmasalahan pengelolaan air limbah. Langkah mereduksi atau pengurangan dampak negatif dari sampah plastik khususnya botol plastik bekas yaitu dengan mengembangkan berbagai jenis teknologi pemanfaatan botol plastik, diantaranya adalah penggunaan botol plastik sebagai media biofilter dalam pengolahan air limbah domestik. Terdapat penelitian terdahulu terkait pemanfaatan botol plastik sebagai biofilter. Botol plastik bekas dapat digunakan sebagai media biofilter dan memiliki kemampuan penyisihan TSS (total padatan tersuspensi), COD (jumlah oksigen yang diperlukan untuk mengurai seluruh bahan limbah yang terkandung dalam air)  dan BOD (oksigen yang diperlukan oleh mikroorganisme untuk mengoksidasi senyawa – senyawa kimia) yang baik. Studi tersebut dimanfaatkan dalam pemberdayaan masyarakat di Desa Pecuk melalui tahapan persiapan dan pelaksanaan. Sosialisasi dilakukan di Desa Pecuk Kecamatan Mijen Kabupaten Demak menggunakan sampel dan penjelasan tentang pentingnya pengelolaan sampah dan limbah, nilai guna botol plastik bekas sebagai biofilter septic tank serta diakhiri dengan diskusi antara tim pengabdian masyarakat dan warga Desa Pecuk. Melalui kegiatan sosialisasi ini dapat menambah wawasan dan pengetahuan warga tentang daur ulang sampah botol plastik melalui pembuatan biofilter tanki septic.Pecuk Village is one of the villages in Mijen District, Demak Regency which is currently experiencing waste problems, especially plastic waste, which is increasing and has not been managed well. Apart from the waste problem, Pecuk Village, based on existing data, is also faced with waste water management problems. Steps are being taken to decrease or mitigate the negative impact of plastic waste, particularly used plastic bottles, by creating various forms of technologies for using plastic bottles, such as the use of plastic bottles as biofilter material in household wastewater treatment. There has been previous study on the use of plastic bottles as biofilters. Used plastic bottles can be used as biofilter medium, removing TSS (total suspended solids), COD (the amount of oxygen needed to decompose all waste materials contained in water), and BOD (oxygen required by microorganisms to oxidize chemical compounds). Through the preparation and execution stages, this study was used to empower the people in Pecuk Village. The socialization took place in Pecuk Village, Mijen District, Demak Regency, and included samples and explanations about the importance of waste management, as well as the value of using used plastic bottles as septic tank biofilters. It concluded with a discussion between the community service team and Pecuk Village residents. Residents can gain more insight and understanding about recycling plastic bottle waste by creating septic tank biofilters through this outreach program

PLANNING CONCEPT OF RISK MANAGEMENT IN CONSTRUCTION PROJECT

Construction project has many risks; therefore it should be managed correctly and implemented from start to finish. Risk management is the correct way to minimize the risk in construction project. In the context of managing risk, people in construction company can analyze the risk that may happened with SWOT analysis as a tool to observe and determine strategy.Keyword: SWOT analysis, risk management, construction projec

STUDI EKSPERIMENTAL SIFAT-SIFAT MEKANIK BETON NORMAL DENGAN MENGGUNAKAN VARIASI AGREGAT KASAR

ABSTRAKBeton terdiri dari 4 komponen dasar pembentuk beton yaitu campuran antara semen, agregat kasar, agregat halus  dan air. Untuk mengetahui dan mempelajari perilaku masing-masing bahan penyusun beton tersebut memerlukan pengetahuan bagaimana karakteristik bahan yang akan dibuat sebagai penyusun beton tersebut. Dalam penelitian ini ingin mengetahui sifat-sifat mekanik beton normal dengan menggunakan mix design beberapa jenis agregat kasar.Analisis data yang kami gunakan adalah analisa data secara kualitatif yaitu dengan menginterpretasi tabel-tabel, grafik-grafik, atau angka-angka yang ada kemudian melakukan uraian dan penafsiran. Dalam penelitian ini menggunakan sampel sebanyak 108 dengan menggunakan mutu beton K-250, dibuat  2 kelompok dan 5 jenis mix design sehingga dari hasil pengelompokkan tersebut dapat dengan mudah dibuat analsis hasilnya.Dari hasil penelitian benda uji beton mutu K-250 dapat disimpulkan bahwa agregat kasar yang ukuran gradasinya 1-2 mempunyai sifat-sifat mekanik yang hasil yang lebih baik daripada agregat kasar yang ukuran gradasinya 2-3 baik pada kuat tekan beton, modulus of rupture dan modulus elastisitas.Hasil benda uji beton berdasarkan sifat-sifat mekanik beton dapat disimpulkan bahwa:Ø Sampel F (25% kricak manual + 75% kricak pecah mesin) dengan agregat kasar ukuran 1-2 menghasilkan kuat tekan beton paling tinggi sebesar 276,66 Kg/cm2 dari standar rencana beton yang dibuat K. 250 Kg/cm2.Ø Sampel F (25% kricak manual + 75% kricak pecah mesin) dengan agregat kasar ukuran 1-2 menghasilkan modulus of rupture paling tinggi sebesar 15,91 Kg/cm2.Ø Sampel F (25% kricak manual + 75% kricak pecah mesin) dengan agregat kasar ukuran 1-2 menghasilkan modulus elastisitas  paling tinggi sebesar 15.944,80 Mpa. Kata kunci: Beton, benda uji, sifat-sifat mekanik beton norma

Design Of Pavement Using Buton Natural Rock Asphalt Stabilized Subgrade Soil

The performance of pavements is governed by the strength of the subgrade, because subgrade is roadbed soil where the pavement structure is laid. If bearing capacity of the subgrade high, deformation of pavement will not occur and it is not easy to deteriorate. In the contrary, if bearing capacity of the subgrade low, pavement deformation will occur and pavement will deteriorate. This research have objectives to analysis the pavement structure of using existing subgrade soil and using subgrade stabilized with Buton Natural Rock Asphalt (BNRA).  The road connecting Semarang - Purwodadi where always in worst condition was used for study in this research. Semarang – Purwodadi road is laid over montmorillonite expansive clay with lower bearing capacity or have low CBR value only 1 to 2 %. To analysis the pavement structure, both flexible and rigid pavement, AASHTO 1993 pavement design are used. The result show that flexible pavement structure laid over stabilized soil have thinner pavement structure compare to the one laid over the subgrade of original expansive clay soil. Similarly for rigid pavement, the thick of concrete slab over the subgrade of expansive clay is 30 cm, and if laid over the subgrade of stabilized expansive clay with Buton Natural Rock Asphalt (BNRA) is only 25cm. It can be concluded that Buton Natural Rock Asphalt (BNRA), have significant influence to the strength and bearing capacity of expansive clay soil.  Keywords: asbuton, stabilized subgrade, expansive clay soil, AASHT

The Effect of Hole Width on Full Height Rectangular Opening Castellated Steel Beam with Diagonal Stiffener Concerning Its Flexural Capacity

The use of a diagonal stiffener in a full height rectangular opening castellated steel beam can prevent the failure mechanism of vierendeel. This results in the flexural capacity of the castellated beam higher than the original IWF profile. The flexural capacity of a castellated steel beam can be optimized by designing the hole width on the web section. This research aims to find out the effect of several values of castellated steel beam hole width on the flexural capacity. In this research, there are 4 castellated steel beam models whose flexural capacity values are calculated using the truss analysis and pushover analysis methods. Based on the calculation results, it can be concluded that the smaller the value of the hole width, the greater the flexural capacity of the castellated steel beam will be. The largest increase in flexural capacity from the original IWF to the castellated beam is 140.93%

PERANCANGAN ULANG STRUKTUR ATAS GEDUNG A RUMAH SUSUN POLITEKNIK PEKERJAAN UMUM (PU) SEMARANG

Perancangan bangunan merupakan suatu hal yang sangat penting untuk diperhatikan dalam proses akan didirikannya sebuah bangunan. Perancangan merupakan salah satu hal mendasar yang harus dikerjakan terlebih dahulu. Ada banyak aturan – aturan dan spesifikasi yang telah ditetapkan untuk merancang sebuah bangunan. Tujuan dalam merancang ulang bangunan ini adalah untuk menganalisis struktur gedung bertingkat untuk beban gempa dan mendesain dimensi serta penulangan balok, pelat, kolom, dinding geser, dan joint. Gedung A Rumah Susun Politeknik Pekerjaan Umum Semarang yang memiliki 8 lantai dirancang menggunakan struktur rangka beton bertulang. Gedung ini memiliki fungsi sebagai tempat tinggal mahasiswa/i Politeknik Pekerjaan Umum Semarang. Perancangan struktur Gedung A Rumah Susun Politeknik Pekerjaan Umum Semarang ini mengacu pada peraturan SNI 1726:2019, SNI 2847:2019 dan SNI 1727:2019. Software menggunakan ETABS V18.1.1 yang berfungsi untuk perancangan permodelan, pembebanan, pelat, balok, kolom, dinding geser. Gedung ini menggunakan sistem ganda yaitu, Sistem Rangka Pemikul Momen Khusus (SRPMK) dan Sistem Dinding Struktural Khusus (SDSK). Hasil analisis gaya geser lantai akibat beban statik arah x dan arah y diperoleh nilai 1.038,68 kN. Beban gempa dinamik senilai 855,92 untuk arah x dan 922,13 untuk arah y. Simpangan antar lantai senilai 147,88 untuk arah x dan 146,18 untuk arah y. Pada perancangan Strong Column Weak Beam telah memenuhi syarat ∑Mnc > 1,2Mnb dengan diperoleh hasil 1068,27 ≥ 429,04 Kata Kunci : Rumah Susun ; SDSK ; SRPM

PEMANFAATAN SERBUK ECENG GONDOK SEBAGAI CAMPURAN BETON MUTU TINGGI

Semen merupakan bahan yang sangat penting dalam pembuatan beton.Pembuatan beton yang baik juga bergantung pada agregat yang digunakan.Penggunaan bahan tambahan kimia sesuai kebutuhan untuk memperkuat hasil beton pun dilakukan demi menghasilhan beton mutu tinggi. Kandungan Eceng Gondok yang memiliki senyawa kimia yang sangat berperan penting dalam pembuatan semen menjadikan Eceng gondok dimanfaatkan untuk dibuat serbuk yang akan digunakan sebagai campuran pembuatan beton. Kandungan dalam serbuk eceng gondok memiliki kesamaaan unsur penyusun dengan semen sehingga dengan penambahan serbuk eceng gondok pada campuran beton maka dapat dihasilkan beton mutu tinggi. Kandungan Kimia Eceng gondok mengandung unsur SiO2, kalsium (Ca), Magnesium (Mg), Kalium (K), Natrium (Na), Chlorida (Cl), Cupper (Cu), Mangan (Mg), dan Ferum (Fe). Dengan memiliki unsur tersebut terdapat kesamaan dengan unsur pembentuk dari semen yaitu Trikalsium Silikat (C3S) atau 3CaO.SiO2, Dikalsium Silikat (C2S) atau 2CaO.SiO2, Trikalsium Aluminat (C3A) atau 3CaO.Al2O3, Tetrakalsium Aluminoferit (C4AF) atau 4CaO.Al2O3.FeO3. Pemanfaatan eceng gondok sebagai bahan tambahan pencampuran beton mutu tinggi dapat menjadi solusi yang tepat, untuk Mendapatkan biaya yang murah dengan mutu yang terbaik. Kata Kunci : Beton,Eceng gondok, Seme

Plastic behaviour of strengthened cold-formed steel section

To date, the use of cold-formed steel on single storey industrial buildings particularly as structural element of a portal frame is restricted. Mostly, its application is as roof and wall framing, cladding, purlins and rails. Compared with hot-rolled steel, the use of cold-formed steel on a building has advantages such as light self-weight and corrosion-free problems, even though these are weaknesses to be overcome. The main problems are local buckling and low connection capacity. From the previous study, it was shown that cod-formed rectangular hollow portal frame using thick section indicated the plastic behaviour. This section is uneasy to be derived at site. Besides, some connection methods have also been suggested by previous researchers using bolts, rivets, press and weld but such the connections cannot reach rigid connection as needed for plastic design of portal frame. This research intends to study strengthening methods of cold-formed steel section and the connection performance improvement using cover plate. From this study, it is expected that cold-formed steel section can achieve plastic section and the rigid connection can be reached. The study was performed in two stages. In the first stage, the study on small cold-formed steel beams was done, while in the second stage, the study investigated a full scale of cold-formed steel beams and the connections. Specimens of this research consist of strengthened cold-formed closed beams and the moment connections. The beams are strengthened using a splice of hot rolled plate attached to the original section by screws and weld. The beams are in various design strength, thickness, screw spacing and number of web screw rows. Three types of connection i.e. welded, unbraced cover and braced cover connections were constructed for the specimens. Self-drilling screws for the section strengthening were applied on the connected members outside the cover plate. The experimental results were compared to the theoretical one. From this study, it can be concluded that the applied strengthening method significantly increase the moment capacity of the cold-formed steel sections. Similarly, the braced cover connection improves the connection to be rigid connection

Cold-Formed Steel Technology in Building Structure and its Problems as an Alternative Solution of Corrosion Resistant Structures at Coastal Areas

This paper aims to determine the technological development of cold-formed steel ishappening today and the problems of its application especially on the building structures. The coldformed steel structures have become alternative could be used in coastal areas due to its corrosion resistant properties. The development of the cold-formed steel use on structures is reviewed. In addition, the advantages and lacks of the cold-formed steel structural members are presented based on the research conducted previously. It is concluded that cold-formed steel technology has great potential to be developed and be applied to building structure even some problems arised have to be overcome especially regarding to local buckling and low capacity of the connectio

Behavior of Normal Concrete Reinforced with Fiber

Concrete is a material with the ability to withstand a fairly high pressure, yet it has a low ability to withstand tension. To be utilized as a structure material, improvements need to be made to increase its tensile strength. Addition of fiber in the concrete mixture is recognized to be one among the existing methods to increase the tensile strength. Considering its high tensile strength, This study aimed to examine the compressive strength, the split tensile strength, the flexural and elastic modulus of the normal concrete with Menjalin fibers. The examination was conducted using a cylinder with the diameter of 15 cm and the height of 30 cm and a beam with the size of 15x15x60 cm. Fiber addition was 0.65% of the total concrete materials with various fiber lengths ranging from 2.5 cm, 5 cm, 7.5 cm to 10 cm. The experiment was made by the means of a concrete cylinder compressive test and a flexural test of unreinforced concrete blocks. Results of the study showed, at the age of 21 days, the highest average compressive strength value of 194.37 kg/cm2 and the split tensile strength of 30.43 kg/cm2 in the concrete with fiber of 5 cm long were obtained. The highest flexural modulus value of concrete occurred in the specimen with the fiber length of 7.5 cm (55.7 kg/cm2), while the highest elasticity of concrete occurred in the specimen with the fiber length of 5 cm (2.45x105 kg/cm2)