Perbandingan Nilai Daya Dukung Tanah Dasar Badan Jalan Yang Distabilisasi Semen Dan Abu Sekam Padi

Strength and durability of road pavement depend on engineering properties of subgrade. However, soils used as subgrade may not satisfy the required quality. Expansive clayey soils can pose problems and cause pavement failure. A research about characteristic of soil stabilized with cement and rice husk ash was conducted to overcome these problems. This paper intends to compare bearing capacity of soft subgrade soil stabilized with cement and rice husk ash. The effectiveness of cement and rice husk ash in improving the engineering properties of soil can be directly compared since the sample of soil was collected from the same location and treated with the same treatment. By adding cement and rice husk ash, the bearing capacity of clayey soil increased significantly. For soil stabilized with cement, the soaked CBR was higher than that of the unsoaked. Opposite phenomenon occurred in soil stabilized with rice husk ash, as its bearing capacity reduced after soaking in the water. Therefore moisture change during design life of road pavement should be anticipated such as using appropriate drainage system

Global Climate Change as Perceived by Elementary School Teachers in YOGYAKARTA , Indigenous Psychology Approach

This study aimed to describe how the global climate change was perceived by teachers of elementary schools. The subjects were 111 teachers from 7 elementary schools in Yogyakarta City and Sleman district. The data were collected using open-ended questions (including perception about the weather, feeling evoked by global warming words and free responses related to global warming issues). The data were analyzed using the technique of qualitative and quantitative content analysis with Indigenous Psychology Approach. The result showed that only one teacher reported that there was no weather anomaly, while 110 teachers reported that they perceived weather anomaly. Of those who perceived weather anomaly mostly referred to natural conditions (including global climatic condition and environmental destruction) and human behavior as its causes. Responses about feeling as evoked by global warming word were classified into three categories, i.e. emotional, physical and irrelevant responses. Free responses about global warming were classified into four categories respectively from the highest frequency of responses: prevention (including statement “must be prevented”, prevention behaviors and prevention efforts), states (including the weather states and feeling), causes (including technological advances and human behavior generally), and others. The research finding was discussed in the frame of environmental concern as a means of character education in elementary school

Sifat Volumetrik Campuran Laston Menggunakan Aspal Modifikasi Getah Pinus dan Limbah Styrofoam

Sifat volumetrik campuran pada laston merupakan salah satu faktor yang menentukan durabilitas (keawetan) lapis perkerasan jalan. Untuk meningkatkan keawetan lapis perkerasan jalan dan mengurangi dampak negatif terhadap lingkungan dapat dilakukan antara lain melalui modifikasi aspal dengan getah pinus dan limbah styrofoam. Tulisan ini bertujuan untuk mengkaji sifat volumetrik campuran laston menggunakan aspal modifikasi getah pinus dan limbah styrofoam tersebut. Sifat volumetrik campuran laston yang dikaji adalah rongga dalam campuran, rongga di antara mineral agregat, rongga terselimuti aspal, density dan bulk specific gravity. Pada penelitian ini digunakan agregat bergradasi rapat yang dicampur dengan aspal modifikasi pada suhu 155 oC dan dipadatkan 75 kali pada kedua sisinya. Pada seluruh benda uji, prosentase limbah styrofoam yang digunakan adalah 6% sedangkan getah pinus sebesar 0%, 1%, 2% dan 3% terhadap berat aspal modifikasi. Hasil penelitian menunjukkan bahwa campuran laston yang menggunakan aspal modifikasi getah pinus menghasilkan nilai VFB, density dan bulk specific gravity lebih besar serta nilai VIM dan VMA lebih kecil dibandingkan dengan campuran yang menggunakan aspal modifikasi limbah styrofoam. Dengan nilai VIM dan VMA lebih kecil, campuran yang menggunakan aspal modifikasi getah pinus menghasilkan daya ikat lebih kuat sehingga memiliki durabilitas lebih tinggi. Ditinjau dari persyaratan laston sebagai lapis aus pada perkerasan jalan, penggunaan getah pinus dan limbah styrofoam sebagai modifier aspal memenuhi persyaratan volumetrik campuran. Volumetric properties of asphalt concrete is important factor to determine the durability of road pavement. Improvement the durability of road pavement and reducing negative impact of the environment can be done by using modified asphalt. This article aims to know the volumetric properties of hot mix asphalt using pine resin and waste styrofoam as asphalt modifier. The volumetric properties include voids in mix, voids in the mineral aggregate, voids filled with bitumen, density and bulk specific gravity. In this study, a continuously graded aggregate was used and mixed with modified asphalt at 155 oC and compacted with 75 blows on both sides. The percentage of waste styrofoam was 6% whereas the percentages of pine resin where 0%, 1%, 2% and 3% by weight of modified asphalt. From the analysis, it can be concluded that asphalt concrete containing pine resin as modifier strengthen the binding between asphalt and agregate, due to increasing value of voids filled with bitumen (VFB), density and bulk specific gravity. Durability of asphalt concrete using pine resin as modifier was higher than that of asphalt concrete using waste styrofoam because of decreasing value of voids in mix (VIM) and voids in the mineral aggregate (VMA). Based on the specification of asphalt concrete wearing course, the use of pine resin and waste styrofoam as asphalt modifier has fulfilled volumetric properties requirements

Analisis Karakteristik Marshall pada Beton Aspal Lapis Pengikat (Asphalt Concrete-Binder Course) Menggunakan Aspal Modifikasi Serbuk Serat Pelepah Batang Pisang

Asphalt modification by adding fiber powder of banana stem can be implemented to improve the performance of pure asphalt. Asphalt concrete binder course AC-BC is a flexible pavement layer that functions to distribute the load towards the foundation layer. So it really needs strength, durability and stability of the materials. For that, it is necessary to use asphalt modification with fiber powder of banana stem which is used as a binding material in AC-BC asphalt concrete mixture. The proper percentage of modified asphalt level will determine the optimum quality of an asphalt mixture. Asphalt concrete specimens were made in 3 (three) samples for each variation of asphalt level by 5%; 5.5%; 6%; 6.5%; and 7%. The asphalt optimum level in the mixture is carried out through volumetric investigation in the form of VMA, VIM, and VFB values and mechanical assessment in the form of stability, flow and Marshall Quetient. The results of data analysis found that the value of VIM, stability and MQ tend to decrease with increasing levels of modified asphalt. On the other hand the value of VMA, VFB and flow tend to rise with increasing levels of modified asphalt. However, from the five variations of asphalt levels obtained asphalt levels of 5% and 5.5% which meet all the specifications of AC-BC asphalt concrete specification. To determine the asphalt optimum level, the average of qualified asphalt level is taken. So that the asphalt concrete AC-BC will produce a better structural performance at 5.25% asphalt level with banana stem fiber powder on asphalt by 0.1%

Waste Cooperatives Development for Improving the Welfare of the Jelantik Village Community, Central Lombok Regency

The "Sapu sae" waste cooperative is a joint effort of community groups in Jelantik Village to collect waste, especially plastic waste, to overcome the problem of plastic waste while improving the welfare of the residents. However, this cooperative is currently no longer operating due to various reasons. Difficulty in collecting waste due to residents' refusal, lack of administrative and financial management capabilities and unclear management of the cooperative are the main reasons why this cooperative is unable to survive. This activity aims to revive village waste management activities. This service activity uses a solution approach method for cooperative problems. The activities are carried out in several stages, including the revitalization of cooperatives, simple bookkeeping and finance training for administrators, waste management training for members, providing minimal assistance for cooperatives and closing with mentoring and evaluation. This activity has been carried out and received a warm welcome from the Jelantik Village community. The waste cooperative has been revived with new legal administrators who have been given bookkeeping training. Cooperative members were also given training in making handicrafts made from waste. Service activities also provide minimal means for carrying out cooperative activities in the form of garbage collection sacks, member savings books and cooperative administration book packages. This activity has been evaluated and shows positive developments with the return of the cooperative and increasing public awareness in waste management

Selection of the Optimum Seed and Media Sterilization Techniques for Muna Teak (Tectona Grandis L.) Micropropagation

The existence of the muna teak (Tectona grandis L.), is currently threatened with extinction, so a muna teak replanting program is needed. Micropropagation techniques can be one solution for the supply of high quality seedlings. The purpose of this study was to obtain the optimum sterilization technique to get the sterilize explants of muna teak and to get the suitable media for in vitro multiplication. The study was conducted in a tissue culture laboratory of the Forest Tree Seed Technology Research and Development Centre in Bogor. This study consisted of two stages and the experimental design used was a completely randomized design. The first phase of the study was the treatment of sterilization techniques consisted of soaking explants in various concentration of clorox solution and the second stage of the study was the treatment of multiplication media. The results showed that the proper sterilization technique to obtain sterilize explants of muna teak seedlings was immersed in 20% chlorox solution for 10 minutes, then immersed in 15% of chlorox for 15 minutes. The best medium for the induction stage and multiplication of Muna teak buds which are modified media plus Benzyl Amino Purine (BAP) hormone as much as 0.1 mg.l-