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Subgrade strength is the main factor in determining the required thickness of any pavement. Therefore, the properties of a pavement subgrade materials must be determined, as they can predict the service life of a pavement. This paper examines the deviation of strength attained by sawdust and lime stabilized expansive soils for subgrade during different curing periods. The methodology used was conducting laboratory tests such as physical properties and mechanical property tests for both treated and untreated soil samples. In the first set-up, the soil was substituted with sawdust in the percentages of 0, 3, 5, and 7% of the dry weight of the soil, and after conducting unconfined compressive strength test, the optimum sawdust percentage obtained was 3%. The 3% sawdust was then mixed with 3% lime and 94% soil for long term tests. The sawdust-lime stabilized samples were cured for 0, 7, 14, and 28 days, and tested for unconfined compressive test and California Bearing Ratio. Based on the analysis of the results, it was concluded that a combination of 3% sawdust and 3% lime significantly improved the California Bearing Ratio and unconfined shear strength, specifically at later curing periods.

High rainfall leads to flood vulnerability and potentially leads to the failure of road pavement which affects the economic loss for the people. However, such road pavement failures need to be studied more deeply to be able to distinguish whether the failure is solely due to flood natural disaster or other factors, such as overloading and poor construction quality. This research is urgently needed because up to now there is no tool for assessing pavement failure as a tool of decision-making system that is able to distinguish road pavement failure causal factors into category of natural disaster or human negligence factors in accordance with the definition of building failure in Indonesia Law no. 2 year 2017. Assessment of the causal factor of failure is very important because it is closely related to the determination of the parties who must be legally responsible. This research intends to develop methods for assessing the damage and failure of pavement as a tool of rapid and accurate decision-making system to determine the factors of pavement failure. To obtain accurate results, a case study was taken on Kendal Timur road to enable a deep evaluation of the factors that causing failure on the road. The results showed that many factors involved in causing the failure of the road, such as un-functional drainage channel, uncontrolled overload due to the closing of weigh stations around the road, and also low quality of road maintenance work so that repeating similar road damages occurred in the not-too-distant future. Based on functional and structural failure analysis, as much as 71%, 10% and 19% of the road were in failed, critical and not-failed conditions, respectively.

The existing drainage system of roads proposed to manage the quantity of runoff from the road only, while the quality remains uncontrolled. In fact the pollutants and waste originated from the road surface contains hazardous substances. Sustainable drainage system (SUDS) concept offers various structures to solve both quantity and quality problems of surface runoff from roads. One of the potential drainage structure is filter drain or infiltration trench develope along the right side and left side of road. It could be developed by retrofitting the existing drainage channel of the road. The objective of this paper proposes the design model of road drainage based on the concept of a sustainable urban drainage system. The model consists of U-ditch channel, reservoir, an infiltration well. The bottom of U-ditch channel completed with a number of holes to make it porous. The channel filled with aggregate to filter the runoff from the road before flow down into the reservoir beneath. The water is then discharged to infiltration well. The model was developed based on rainfall data and other physical characteristics in Ambarawa City, Semarang Regency, Central Java.The channel dimensions and the depth of aggregate filter were designed base on runoff volume. The relationship among rainfall, runoff volume, area ratio, and drainage dimension are obtained. The results concept of sustainable road drainage is obtained in addressing the quality and quantity of rainwater.

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Road pavement is one of infrastructures that is currently getting most attention due to its important role in accelerating the economic growth rate of an area, opening up isolated regions and improving the connectivity among them. A road infrastructure has a life-cycle which starts from design to reconstruction. Among all phases of road life-cycle, maintenance work plays an important role to maintain the performance of the road always in the top level. To conduct road maintenance work, it is necessary to evaluate the condition of the road, both structurally and functionally. To date, road functional condition assessment uses two indices, namely surface distress index (SDI) and international roughness index (IRI). The SDI, currently used by Directorate General of Highway (DGH), has a simple procedure and is easy to use. Talking about accuracy in estimating the functional conditions of the road, it seem that SDI is still far from satisfactory. In this study, an attempt to evaluate SDI, particular for crack damages, will be proposed by considering all types of crack damage and their corresponding dimension and severity level. Pavement condition index (PCI), the most comprehensive method for evaluating the functional conditions of the road, will be used as the reference. It looks like that PCI is the best choice as a tool to evaluate road functional conditions in Indonesia, however, the weak capability of the field personnel becomes a constraint in optimizing the potential of PCI. Therefore, updating SDI could be now considered as the best solution.

Expansive soils have proved to be problematic to most Civil Engineering structures. Several researchers have tried to look for different materials which can alter the properties of these poor soils, and among them are lime and cement, which are expensive. Considering the vast quantities of sawdust produced in woodwork departments, they can be used as a secondary stabilizer, thus leading to sustainable technologies. Sawdust not only acts as a cheap stabilizer but also reduces the problem of environmental pollution caused by its poor disposal. This paper examines the geotechnical properties of expansive soil stabilised by Keruing sawdust. The sawdust used as partial replacement of soil in the ratio of 0, 3, 5, and 7% by the dry soil weight. The investigation was done by conducting laboratory tests on both stabilised and non-stabilized soils. The results showed that Keruing sawdust significantly improved the geotechnical properties of the soil by reducing the plasticity index from 64% to 36% at 0% and 7% sawdust, respectively. The unconfined compressive strength and California Bearing Ratio also improved at 3% sawdust + 97% soil. It concluded that Keruing sawdust, a waste material could be used as a cheap additive to the expansive grounds.