Experimental research was carried out on 11 different clayey materials to determine the main characteristics of the drying and wetting paths and the influence of initial state and other factors. Normally consolidated paths are shown to have a large saturated domain, in which a negative pressure is equivalent to an isotropic stress increase; such paths can be derived from correlations with the liquid limit. On the other hand, the behavior of overconsolidated or dried samples is largely dependent on the range of stresses and negative pressures. Key words : suction, unsaturated soils, drying, wetting, correlations, models.

Infrastructure is vital for regions life, mean while the infrastructure is always onerous and complex. The region must be able to manage its infrastructure well. Therefore the Basic Principle of Infrastructure Asset Management need to be well defined. This paper presents the result of an attempt to define the Basic Principle Infrastructure Asset Management. The Infrastructure Asset Management is defined as the science, the knowledge and the program to manage the infrastructure life in order to be able to well function in sustainable way, efficient and effective. The Infrastructure Asset Management knowledge consists of 7 basic knowledges, i.e on infrastructure, infrastructure function, infrastructure physical structure infrastructure externalities, infrastructure life cycle, infrastructure economy, and infrastructure managing organization. To master the Infrastructure Asset Management analyse tools must be added such as: statistics, decision making, risk management, quality management, strategic management, etc.

Commuter Train is one of the facilities that must be managed properly, economically and efficiently by the principles of Facility Asset Management. The availability of infrastructure and vehicles for this facility is adjusted based on passenger demand. This requires sufficient knowledge on the travel behavior characteristics, i.e., different characteristics composition proportion. Travel behavior survey requires the appropriate formula or method to calculate the minimum sample size, for this case are proportions of pq, pqr, pqrs etc. Therefore, a search for Minimum Sample Size Calculation Method for the Travel Behaviour Survey is needed. A literature study was employed for this search. This is important because the calculation method for the minimum sample size for proportions pq exists, but for the proportion of pqr, pqrs, etc do not yet exist. The results of the study indicates that the SR Method is the most appropriate method for calculating the minimum number of samples for the case of the proportion of pqr, pqrs, pqrst, etc. The SR Method is developed based on Goodnees of Fit method combined with the Maximum Acceptable Error principle. The combination of the two is named the MAECCL (Maximum Acceptable Error on a Certain Confidence Level) principle.

ABSTRAKInfrastructure Asset Management is essential. In Indonesia nowadays, they, who enter and take a role in Infrastructure Asset Management is either an engineer or an economist. Both the engineer and the economist tend to see the infrastructure in infrastructure engineering way and the economy of infrastructure. A Basic View of Public Infrastructure for Infrastructure Asset Management in Indonesia needs to be formulated. The Public Infrastructure is viewed through several different following basic concepts:

Abstract. Fly ash is a by-product obtained from coal combustion process. Some of the utilization of fly ash is to produce geopolymer products which have high compressive strength, fire, chemical resistance. This paper proposes fly ash from unit 1-7 Suralaya Power Plant Indonesia. The aims of this study are to obtain characterization of fly ash and mechanical properties of geopolymer paste based on variations of the alkali activator ratio. The method was based on previous research and laboratory investigation. XRF and compressive strength were analysed in this study. Alkali activator was obtained from NaOH and Na2SiO3 mixture. The ratio of Na2SiO3 to NaOH was in the range of 0.5-2.5. Geopolymer paste was casted in acrylic cylinders with a diameter of 2 cm and a height of 4 cm. The curing was conducted at room temperature until the day for the compressive strength test at 28 days. The result showed that the fly ash is classified as F class. Increasing the alkali activator ratio influenced the strength. The best composition of geopolymer paste is made with NaOH 8M, and the mass ratio of Na2SiO3 to NaOH is 2.5. This composition produced compressive strength of 98.6 MPa.