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The effect of the electric fields on crystalline structure and functional group of mendong fiber (Fimbristylis globulosa) AIP Conference Proceedings 1778, 030007 (2016) Abstract. Road deterioration has been a significant problem in Indonesia. To minimize this deterioration and it is necessary to pay extra attention to material selection and one solution is to formulate an asphalt mix that has a high physical properties and one way to do this is to use latex as an additive. The purpose of this experimental study was to investigate the effect of latex DRC 60 on the physical properties of asphalt concrete wearing course (ACWC). The Indonesian National Standards, ASTM and AASHTO were used and all test results had to meet their standards. Four levels of latex content were investigated in this study, namely, 0%, 2%, 4% and 6% by weight of latex-bitumen blend. The result of the tests made on the ACWC blends indicated that the addition of latex changed the physical properties of ACWC. Unit weight and voids filled with bitumen (VFB) increased with the increase in latex content, suggesting that the bitumen-latex mix are more durable than that without latex. The addition of latex decreased the Voids in mix (VIM) and the Voids in mineral aggregate (VMA) of ACWC. The best asphalt mix was that with 4% latex.

Regency roads are currently the worst performing of all road networks in Indonesia despite being the majority within the Indonesian road network system distribution. To be able to properly handle road treatments, it is necessary to be aware of factors that influence regency road performance. Research on bureaucracy as a variable to improve the performance of regency roads in Indonesia has never been done before. The purpose of this study is to evaluate the effects of bureaucracy on the performance of regency roads in Indonesia. Data collection was carried out by distributing questionnaires to as many as 54 respondents, consisting of officials at the Regency public works office in East Java Indonesia. The analysis method used in this research is the structural equation model -partial least square (SEM-PLS). Bureaucratic factors were analyzed along with four other factors that are postulated to be affecting regency road performance, namely; existing conditions, human resources, maintenance and rehabilitation funds, and the road treatment technique used. Research results showed that bureaucratic factors are the most critical in determining regency road conditions. Bureaucracy has the biggest effect on road performance. Bureaucracy has indirect effects of 0.268 to the road performance, it is higher than that of an existing condition. Meanwhile, the existing condition has an indirect effect of 0.147. Bureaucracy also has a direct influence on the placement of human resources and maintenance and rehabilitation funds. While maintenance and rehabilitation funds, human resources and existing road conditions affect road treatment processes. Lastly, road treatment directly affects road performance.

One aspect that needs to be considered in the application of asphalt pavement is the fact that asphalt is a non-renewable resource which requires constant maintenance throughout its lifetime. Thus, developing a mix with asphalt contents reduced to the minimum is a challenge in and of itself. Latex, in this case, would seem to be potentially viable additives. The aim of this research is to investigate the effects of using latex as an additive to minimize the use of asphalt in asphalt concrete wearing courses (ACWC). Four varying amounts of latex were mixed with asphalt at 0%, 2%, 4%, and 6% of the total weight of an asphalt binder. A wet process was then employed to blend the mixtures together. Afterward, the latex-asphalt mixtures were added to an aggregate to form various mixtures ranging from 5% to 7% of the aggregate and the incremental weight of 0.5% of the latex-asphalt ACWC. For each latex-asphalt-aggregate mixes, the optimum binder content was determined based on stability, flow, Marshall quotient, voids in the mineral aggregate (VMA), voids in the mixture (VIM) and voids filled by the binder (VFB). The results of this experiment indicated that the addition of latex reduces the need for asphalt contents.

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The aim of this study are, to determine the influence of achievement motivation, the inspiration of the learning model, service satisfaction, career expectations, to the achievement of learning and self-confidence Polytechnic of Road Transport Safety student. The sample in this research consist of 146 students of Polytechnic of Road Transport Safety. The data obtained from questionnaires distributed to the respondents. After the data collected continued with the validity and reliability test by using the formula Confirmatory Factors Index then the data were analyzed by using SEM technique. The results showed in general, the conclusion of this research there is influence of achievement motivation, inspiration from learning model, service satisfaction, and career expectation toward learning achievement and self-confidence of student of Polytechnic of Road Transport Safety. A more representative service model is needed for students such as the use of internet-based learning facilities to facilitate student access to meet the information needed to facilitate the learning process. Student service quality is the ability of lecturers to consistently meet student expectations.

Abstract.It is well known that presence of water in a bituminous mix is a critical factor which can lead to premature failure of flexible pavements. This requires solutions one of which is to formulate an asphalt mix that has a high resistance to moisture and one way to do this is to mix latex with the asphalt mix. The purpose of this experimental study was to investigate the effect of water on Marshall stability of asphalt concrete wearing course (ACWC) made with a latex-bitumen binder. Latex-bitumen was mixed with aggregate and four levels of latex content were investigated in this study, namely, 0%, 2%, 4% and 6% respectively by weight of asphalt. Wet procces was used in the blending of mixtures. The procedure used to obtain the optimum binder contents conformed to the Marshall procedure (SNI 06-2489(SNI 06- -1991. Six Marshall specimens at optimum binder content were prepared for each binder mix investigated. Three of six specimens from each group were tested under Marshall standards. The remaining specimens were tested by immersion in a bath at 60⁰ C for 24 hours. The Marshall index of retained stability was used to evaluate the effect of water on the Marshall stability of ACWC. The results indicated that the addition of up to 4% latex to ACWC mix increased the retained Marshall stability, whereas the addition of latex above 4% decreased the retained stability of the mixture. The addition of 4% CRM significantly improved the retained stability of the mixture and was the best latex -ACWC mix.