Sigit Pranowo Hadiwardoyo

Small and large strain behaviour of an unsaturated compacted silt

ABSTRACT The results of small and large strain triaxial tests and matrix suction measurements, performed on a compacted low plasticity silt under different conditions of water content, density and confining stress, are presented. Simple models are proposed to interpret the results, one based on an empirical approach and the other one derived from micromechanics. Based on the calculation of the capillary forces between individual particles and using a single parameter, the micromechanical model yields a satisfactory interpretation of the changes in the elastic modulus and maximum strength of the soil with water content.

Genetic Algorithm Applied for Optimization of Pavement Maintenance under Overload Traffic: Case Study Indonesia National Highway

National Road Network which consists of a traditional road structure and modern roads, require planned maintenance and should be in accordance with the needs. The limited choice of available national road network and the deviation of the overloading encourage the government to be more responsive to carry out maintenance management. The institution in charge of road maintenance is often constrained by the limited budget available. A two-objective optimization model considers maximum roughness and minimum maintenance cost for used road network with overload. The study was conducted on the entire national road network in West Java which are paved with flexible pavement. In the proposed approach, data mining model are used for predicting the roughness index over a given period of time. Routine and periodic maintenance are chosen in this study. Multi-objective optimization model was developed based on Genetic Algorithms. Budget constraints and overloading are the two constraints in the developed model. Based on the R-Tools result, the Pareto optimal solutions of the two objective functions are obtained. From the optimal solutions represented by roughness index and cost, an agency more easily obtain the information of the maintenance planning. Results of the developed model has been implemented through the selection of maintenance on the road network scenarios with different levels of overload.

Prediction of surface distress using neural networks

The Authors are grateful to the Lembaga Pengelola Dana Pendidikan (LPDP) for the financial support provided to this thesis through the grant financed by the Ministry of Finance Republic of Indonesia.

New optimization strategies of pavement maintenance: A case study for national road network in Indonesia using integrated road management system

A road network requires timely maintenance to keep the road surface in good condition onward better services to improve accessibility and mobility. Strategies and maintenance techniques must be chosen in order to maximize road service level through cost-effective interventions. This approach requires an updated database, which the road network in Indonesia is supported by a manual and visual survey, also using NAASRA profiler. Furthermore, in this paper, the deterministic model of deterioration was used. This optimization model uses life cycle cost analysis (LCCA), applied in an integrated manner, using IRI indicator, and allows determining the priority of treatment, type of treatment and its relation to the cost. The purpose of this paper was focussed on the aspects of road maintenance management, i.e., maintenance optimization models for different levels of traffic and various initial of road distress conditions on the national road network in Indonesia. The implementation of Integrated Road Management System (IRMS) can provide a solution to the problem of cost constraints in the maintenance of the national road network. The results from this study found that as the lowest as agency cost, it will affect the increasing of user cost. With the achievement of the target plan scenario Pl000 with initial value IRI 2, it was found that the routine management throughout the year and in early reconstruction and periodic maintenance with a 30 mm thick overlay, will simultaneously provide a higher net benefit value and has the lowest total cost of transportation.

Contribution of Short Coconut Fiber to Pavement Skid Resistance

The use of synthetic and natural fibers in composite materials has been proven to increase strength and reduce required amounts of basic building materials. Previous research has determined that fibers have a high tensile strength and the potential to increase the cohesive and tensile strengths of asphalt mixtures. Additionally, previous research suggests that skid resistance is influenced by changes in the asphalt penetration grade. Short decorticated and pulp coconut fibers were used as additives in this study. Short coconut fibers measuring 0.5-1.25 cm were mixed with pen 60/70 asphalt to yield fiber contents of 0%, 0.75% and 1.5%. The fibrous asphalt was mixed with asphalt-concrete-wearing-course-grade aggregate. The asphalt concrete mixture was molded and compacted with a wheel tracking compactor using an 8.16-ton standard vehicle axle load. Specimens were subsequently tested with a British pendulum tester at temperatures of 26 oC, 30 °C, 35 °C, 40 °C, 45 °C, and 50 °C. Skid resistance decreased with an increase in pavement surface temperature. The inclusion of 0.75% coconut fiber in the asphalt mixture improved skid resistance but did not improve resistance to increased road surface temperatures.

Effect of Fibers Content on the Tensile Properties of Coconut Fibers Reinforced Cement Mortar Composites

The coconut fiber presents higher ductile properties than other natural fibers. In previous studies, it demonstrated than Indonesian coconut fibers presents an improved tensile strength and failure strain after washed with water and dried. The coconut fibers have the potential to reinforce material for construction, especially in earthquake areas such as tropical countries. The purpose of this research is to assess the benefit brought by coconut fibers content on the tensile behavior of mortar composite. Splitting tensile strengths were measured and microstructure observed using scanning electron microscopy (SEM). The influence of fiber content (expressed by a mass ratio fiber/cement) is investigated. The results show that a fiber content of 5% allows a 10 times higher deflection and presents a 1.5 times higher tensile strength than mortar without fiber. Further studies will focus on the bond strength between the fiber and the cement mortar matrix.

Road maintenance strategy with characteristic of drainage condition based on pavement performance

One of the causes of road deterioration is inundation due to poor drainage conditions. Delays of repair will only exacerbate the distress of road and increase the maintenance costs. This study aimed to determine the pavement maintenance cost for outer ring road of Universitas Indonesia using Life Cycle Cost Analysis (LCCA) method and to determine the most cost-effective maintenance strategies based on the analysis of pavement performance. Based on three pavement maintenance scenarios, the result showed that the most cost-effective maintenance strategy is the first scenario, namely pavement maintenance every two years, with the lowest value of Net Present Value (NPV) of IDR 23,490,602.00. The comparison of NPV values showed the potential reduced cost of IDR 18,826,750.00 from pavement maintenance budget using overlay if the first scenario strategy is implemented.One of the causes of road deterioration is inundation due to poor drainage conditions. Delays of repair will only exacerbate the distress of road and increase the maintenance costs. This study aimed to determine the pavement maintenance cost for outer ring road of Universitas Indonesia using Life Cycle Cost Analysis (LCCA) method and to determine the most cost-effective maintenance strategies based on the analysis of pavement performance. Based on three pavement maintenance scenarios, the result showed that the most cost-effective maintenance strategy is the first scenario, namely pavement maintenance every two years, with the lowest value of Net Present Value (NPV) of IDR 23,490,602.00. The comparison of NPV values showed the potential reduced cost of IDR 18,826,750.00 from pavement maintenance budget using overlay if the first scenario strategy is implemented.

Influence of Void in Mix on Rutting Performance Hot Mix Asphalt Pavement with Crumb Rubber Additive

Pavement construction is expected to support vehicle loads and be weather- and water-resistant. In tropical regions with high temperatures and high rainfall intensity, pavement design and construction must consider the effects of temperature. The addition of crumb rubber (CR) can improve the performance of asphalt concrete in response to vehicle loads and ambient temperature. Fiber-shaped CR can be mixed with the aggregate and bitumen in asphalt concrete. In this study, CR was added to the aggregate in a type of asphalt concrete for wearing courses known as hot mix asphalt (HMA). A series of tests were conducted using the Marshall standard or immersion and wheel tracking machine (WTM). CR was added to the HMA at 5%, 10%, 15%, and 20% in aggregate and further mixed with bitumen with 60/70 penetration grade. The additive materials increased the value of the Marshall stability compared to the virgin asphalt mixture. However, this result was not obtained in the WTM test; the addition of CR increased rutting compared to the asphalt mixture without additive. The addition of CR to HMA reduced the voids in the mix, and weakened the capacity of the asphalt concrete to support repeated vehicle wheel loading.

Impact of traffic composition on accessibility as indicator of transport sustainability

Sustainable transport is closely related to quality of life in the community at present and in the future. Some indicators of transport sustainability are accessibility measurement of origin/destination, the operating costs of transport (vehicle operating cost or VOC) and external transportation costs (emission cost). The indicators could be combined into accessibility measurement model. In other case, almost traffic congestion occurred on the condition of mixed traffic. This paper aimed to analyse the indicator of transport sustainability through simulation under condition of various traffic composition. Various composition of truck to total traffic flow are 0%, 10% and 20%. Speed and V/C are calculated from traffic flow to estimate the VOC and emission cost. 5 VOC components and 3 types of emission cost (CO2, CH4 and N2O) are counted to be a travel cost. Accessibility measurement was calculated using travel cost and gravity model approaches. Result of the research shows that the total traffic flow has indirect impact on accessibility measurement if using travel cost approach. Meanwhile, the composition of traffic flow has an affect on accessibility measurement if using gravity model approach.

Analysis on logistic company action toward the access restriction policy on freight vehicle

The high volume of freight vehicles that enters, leaves or passes through the urban areas, especially Jakarta, has caused traffic congestion. Local authority plans to perform the access restriction on freight vehicles on the Jakarta Outer Ring Road (JORR) to reduce the congestion on that toll road. The study aims to analyze the alternative solutions of the logistics companies to overcome the impact of such policy. The data collection is done by interviewing 102 truck drivers and 7 staffs of logistic companies that use JORR. The results show that the most preferred action is shifting the operating time. Based on the open test, access restriction policy on JORR may cause a significant impact on the operational costs of delivery. Shifting the operational time will increase the operating cost by 1.71%, while turning the route will increase the operating costs by 4.35%. Moreover, changing the mode will reduce the operating expenses by 50%, and the combination action of shifting the route and the time will incr...