The temperature within the asphalt pavement layers varies due to the influence ofenvironmental factors including air temperature, humidity, solar radiation, wind speed, and the reflectance of pavement surface. The temperature distribution on the cross section of asphalt pavement layer is considerably important in connection with the strength characteristics of various asphalt pavement designs. This study develops model of asphalt pavement temperature for tropical climate conditions in Indonesia which has a specific climate characteristics. Indonesia is located on a narrow range of latitudes (60 North - 110 South) and is crossed by the equator. Indonesia has a tropical climate and experiences lots of sunlight, rainfalls and high humidity throughout the year. The national road of Denpasar - Gilimanuk (Km 102) segment, Negara regency in the western of Bali is selected as a case study area. Thermocouples sensors equipped with data loggers were installed in various depths. Based on the SAGA Technology program, the temperatures were recorded every 30minutes. About 336 observational data were recorded which include hourly variations of temperature and humidity as well as pavement temperature in various depth. It was found that there was a strong positive linear correlation (r > 0.8) between the air temperature and the temperature of the asphalt pavement. On the other hand, a strong negative linear correlation (r > -0.8) between the humidity and temperature of the pavement was found. Linear regression models were developed to predict the temperature of the asphalt pavement by using temperature and humidity as independent variables. The results indicated that the model has a good estimation accuracy

Construction of the first toll road in Indonesia, namely Jagorawi connecting Jakarta and Bogor, started in 1973 and operated in 1978. In further developments, since 1987, the government provides an opportunity for the private companies to manage toll-road through a public private partnership (PPP) with Build Operate Transfer (BOT) scheme. Using this scheme, the private sectors build, operate at their own expense and after the period of the concession, they should hand it back to the government. In the construction phase, all the risks that must be handled by the private sectors (either in the form of financial or technical one) generally have be planned and managed, but not the ones occurred during post-construction (operational) phase, where a lot of them are often unexpected or unpredictable. The purpose of this study was to analyze how the post-construction risk management applied to the toll road with Build Operate Transfer (BOT) scheme from the operator's point of view. In this study, the risk of post-construction of toll roads were mapped and evaluated. For this purpose, risk identification, risk levels and strategies in response to the risks that occur in the post-construction were performed. Two relatively new toll roads opened to the public, i.e. Semarang -Solo toll road section 1 and 2; and Kanci – Pejagan toll road, were selected as case studies. The process of data collection was done by means of questionnaires and interviews to the parties concerned. The method used for the analysis of risk management was Risk Breakdown Structure (RBS). Data were analyzed by ranking the risks and risk responses, and then the proposed risk management strategies were selected. The results of this study indicated that the highest risk that may occur in Semarang - Solo toll road section 1 was associated with less effective maintenance of damaged surface of the road so that it contributed on the increase of the overhead cost. On the other hand, the highest risk for Kanci – Pejagan toll road was the unexpected projected revenue in the business plan.

Prestressed concrete structures, designed to enhance the compressive strength of concrete through internal pretension, are increasingly susceptible to serviceability issues caused by rising live loads, material degradation, and environmental impacts. Strengthening or retrofitting offers a practical and cost-effective alternative to full replacement. This study investigated the flexural strengthening of prestressed concrete T-beams in the negative moment region using near-surface mounted (NSM) carbon-fiber-reinforced polymer (CFRP) rods. Validation against experimental results from the literature demonstrated high accuracy, with an average numerical-to-experimental ultimate load ratio of 0.97 for reinforced concrete T-beams strengthened with NSM-CFRP rods, a negligible difference of 0.49% for prestressed concrete I-beams, and a minimal error of 1.30% for prestressed concrete slabs strengthened with CFRP laminates. Parametric studies examined the effects of CFRP rod embedment depths and initial prestressing levels. In certain cases, achieving the minimum embedment depth is not feasible due to design or construction constraints. The results showed that fully embedded CFRP rods increased the ultimate load by up to 14.02% for low prestressing levels and 16.36% for high levels, while half-embedded rods provided comparable improvements of 11.20% and 15.76%, respectively. These findings confirm the effectiveness of NSM-CFRP systems and highlight the potential of partial embedment as a practical solution in design-constrained scenarios.

Most rigid-pavement design methods in use today adopt the Westergaard’s approach that characterizes pavement foundation by k , the modulus of subgrade reaction. k is measured by a standard plate loading test conducted in the field. However, since this test is elaborate, expensive, and time consuming, the k value of a subgrade soil is usually estimated from other soil properties. In this regard, the relationship between k and the modulus of elasticity E of the soil is of special interest. This is because E is a fundamental engineering property and that there exists various test methods for determining E either in the field or in the laboratory. This paper proposes a procedure to estimate k from E by establishing an equivalency between two theoretical pavement models, a model of pavement slab supported by an elastic solid foundation (termed the E model) and a model of pavement slab supported by a dense liquid foundation (termed the k model). Instead of matching the k and E models directly as is done in curr...

Era kini ditandai dengan penekanan pada konsevasi energi, beton ramah lingkungan dan beton hijau. Semen merupakan bahan utama pembentuk beton, dan juga penyumbang pencemaran udara terbesar di antara bahan penyusun material tersebut. Semen slag atau Ground Granulated Blast Furnace Slag (GGBFS) yang merupakan hasil pengolahan limbah industri baja menjadi salah satu alternatif yang diminati karena proses produksi dan lebih ekonomis bila dibandingkan dengan Portland Cement (PC). Material yang mempunyai sifat cementitious ini berpotensi untuk menggantikan sebagian semen dalam campuran beton dengan tetap mempertahankan kelebihan sifat mekanis beton. Penelitian ini dilakukan di laboratorium dengan pengujian benda uji yang telah didesain dengan komposisi substitusi semen slag sebesar 0%, 10%, 20%, 30%, 40%, dan 50% dari berat semen yang dibutuhkan dan pada umur 28 hari. Sebagai benda uji kontrol beton direncanakan dengan kuat tekan f’c = 38 MPa. Semen slag yang digunakan berdasarkan referensi memiliki activity index grade 80. Penelitian dilakukan untuk mengetahui kinerja semen slag pada beton melalui pengamatan kuat tekan (f’c), hubungan tegangan-regangan (fc - ε) dan modulus elastisitas (E) beton. Pengujian menunjukkan bahwa substitusi slag menyebabkan terjadinya penurunan kuat tekan beton, regangan dan modulus elastisitas pada umur 28 hari karena adanya proses kimia yang lebih lamban daripada PC.

Asphalt pavement consists of aggregates resulting in a waste material at end of its life. The aggregates can be reused as basic material for asphalt or cementitious binding agents. In both scenarios, the recycled aggregates should provide a good bond with the binder to achieve strength. This study focuses on reusing recycled asphalt aggregates (RAA) in mortar. The major weakness of RAA is the thin oily film originating from the asphalt residue, weakening the bond with cement. The pyrolysis method is accessed in an attempt to overcome this weakness. Three scenarios were investigated; the use of virgin aggregates (VA), RAA, and pyrolysis recycled asphalt aggregate (PRAA) as constituent in mortar. All variables were set a constant except for the aggregate type, the VA mortar function as controlling element. This research is methodologically based on experimental data conducted in the laboratory, while aggregate samples were taken from the field. To analyze the influence of pyrolysis to the aggregate-to-cement bond behaviour, qualitative and quantitative data were collected. The quantitative data were the mechanical properties, the mortar tensile, and compression strength. The qualitative data were obtained from scanning electron microscope readings to visually observe the aggregate surface roughness and voids, including the aggregates cross-section and pre-existing micro-cracks in the aggregate-to-cement interface. Supporting data were the aggregates‘ abrasion rate and absorption. The RAA resulted in a significant mortar strength decrease. This conclusion was supported by the findings of pre-existing cracks in the interfacial transition zone. The pyrolysis method improved the compression strength but negligibly affected the tensile behavior. The compression and tensile strength increased as a function of time for both RAA and PRAA, and a strength convergence was reached at 28 days. The PRAA is considered an option for reuse in mortar, supporting nature conservation.