No abstract

Styrofoam waste presents the environment issue because it is difficult to decompose. As an effort to recycle this pollutant, styrofoam can be utilized as an additive in asphalt concrete mixture. The use of additives aims to create a flexible pavement layer having good performance and meet the requirements. The purpose of this study is to find out whether the addition of styrofoam can improve the quality of asphalt mixtures, and look for alternative additives that can increase asphalt pavement performance. In this study, researchers used food container styrofoam as an addition and incorforated into Asphalt Concrete Wearing Course (AC-WC) mixture. The styrofoam content was 6.5%; 6.75%; 7% ; 7.25%; and 7.5% of asphalt weight. The optimum asphalt contentused is 5.5%. The value of the optimum stability was 3126,002 kg, found at 7.25% of styrofoam content. The best results of Marshall test was obtained at 6.5% of styrofoam content  with stability value  1362,045 kg, VIM value 4,96%, VMA 15,025%, VFA 67,800%, flow 3,44 mm, and MQ 416,338 kg / mm.

The traffic load repetition gives pressure on road may cause the settlement on road embankment especially on weak soil. One of the method to solve this problem is the use of lightweight material called foamed mortar as embankment material. In this study the authors use a foam agent as an added material from a mixture of sand, cement, water to make foamed mortar that can be applied to road foundation. This research is carried out to investigate the effect of variation of foam to water on compressive strength. From the results of mortar compressive strength test with variations of 1:20, 1:25, 1:30, 1:35, 1:40, the mean of compressive strength occurs at 28 days with the following variation are 2927 kPa, 2056 kPa, 1352 kPa, 790 kPa, and 747 kPa respectively. Based on the test results, variations of 1:20, 1:25, and 1:30 have met the compressive strength required at 800 kPa, while the variations of 1:35, 1:40 are below the target.

Porous asphalt is an alternative in flexible pavement which is considered to make water seep into the soil. In previous research have been tested the mixture of porous asphalt that meets porous asphalt porosity requirements, but found the weaknesses that the stability is still lower than the standard required. Based on result obtained before, the study is aimed at investigating the use of mixture composition variable with different percentages until the optimal conditions were obtained, namely making a normal mixture, 15%, 18.75%, 22.5%, 26.25%, 30% as sand composition reduction. The percentage of sand reducted from previous composition with different asphalt variations. Tests are carried out using the Marshall method. Sequence of tests show that the materials used for experiment meet the requirement. Optimum Asphalt Content obtained for the mixture are 6% of the total mixed weight. The best Marshall characteristics for AC-WC porous asphalt obtained are at the percentage of 26.25% sand reduction.

One of concrete construction development is the use of geopolymer concrete which is environmentally friendly and efficient in regard to energy utilization. In this study, four combinations of fly ash (FA) and rice husk ash (RHA) was used, namely: i) 100% FA and 0% RHA, ii) 75% FA and 25% RHA, iii) 50% FA and 50% RHA, and iv) 25% FA and 75% RHA, with addition of alkaline solution mix of Na2SiO3 and NaOH with a ratio of 5:1 at 7 days, 14 days, and 28 days of concrete age, with cube samples and will be done a compressive strength test of 225 kg/cm2 (28 days of concrete age). This study aims to determine the optimum variation and analyze the compressive strength of geopolymer concrete using FA and RHA with the addition of an alkaline solution of Na2SiO3: NaOH = 5: 1. Results found that the optimum variation was in the geopolymer concrete mix of 100% FA and 0% RHA with a compressive strength value of 395.643 kg/cm2 (28 days of concrete age), whereas other variations have shown a decrease of compressive strength compare to the normal concrete. Therefore, the geopolymer concrete variation of 100% FA and 0% RHA has a higher compressive strength because the cement substitute used (100% fly ash) contains the right chemical composition in which it can react with alkaline solutions properly. Meanwhile, rice husk ash contains a composition that is not appropriate to be reacted with alkaline solutions. This shows that fly ash is a suitable substitute for cement for geopolymer concrete. In the other hand, rice husk ash is not suitable for use as a substitute for cement in geopolymer concrete.