A Practice for the Application of Waste in Road Asphalt Pavements in an Eco-Friendly Way

The integration of circular economy principles in the design of road pavements raises the problem of obtaining high-performance asphalt mixtures for reduction of waste and environmental pollution compared to traditional solutions. In this study, the base and binder layers of road asphalt pavements were prepared by using reclaimed asphalt pavement and construction and demolition waste as coarse aggregates, while jet grouting waste and fly ash served as fillers. A leaching test was performed for the marginal materials, after which the engineering performances of the designed asphalt mixtures were investigated through laboratory tests. A life cycle assessment methodology was applied to determine the life cycle impacts of one cubic meter of each asphalt solution. Next, a multi-criteria decision analysis (MCDA) was performed for the solutions suggested for the binder and base layers. Finally, a sensitivity analysis was conducted to identify the most suitable MCDA solutions by varying the weights for a total of 24 different weight configurations. The results of this work revealed that the solutions utilizing jet grouting waste (in particular, the hot asphalt mixture for the binder layer and cold asphalt mixture for the base layer) were preferred to other traditional and alternative solutions in most decision-making scenarios.

Study on Tyre Rubber Modified Bitumens Mix for Road Asphalt Mixtures

In this study the strength & stability characteristics of bituminous mix for 80/100 grade bitumen is to studied and the effect of waste crumb rubber strength and stability characteristics in Bituminous mix and rubber bituminous mix is analyzed. Keywords: voids in mineral aggregates (VMA), voids filled with bitumen (VFB) Method, Crumb rubber, Crumb rubber bituminous mix, stability, flow, Bulk Density

Analisa Karakteristik Getaran Pada Mesin Asphalt Mixing Plant Tipe Apollo ANP- 1500 Berdasarkan Kapasitas Pembuatan Aspal Jalan Pada Daerah Horizontal, Vertikal Dan Longitudinal Berdasarkan Time Domain

Asphalt mixing plant machine is a tool used to process several materials into road asphalt, where it is necessary to know how to analyze the vibration characteristics of the asphalt mixing plant machine based on the capacity of making asphalt road in horizontal, vertical and longitudinal areas based on the time domain. The research method is carried out by collecting data on the amount of deviation, speed and acceleration that arise due to the processing of several materials so as to produce road asphalt based on differences in the capacity of different asphalt processed. Based on the measurement results, it is found that the highest vibration occurs at the asphalt mixing plant machine seat for a capacity of 60 tons/hour where the magnitude of the deviation is 0.222 mm in the horizontal direction at 100 seconds, the largest velocity is 11.99 mm/s horizontally in the second 40 mm/s and the largest acceleration is 369.7 mm/s2 in the horizontal direction of the 20th second. According to the ISO IS 2372 standard, the vibration of the Apollo ANP-1500 asphalt mixing plant machine enters class IV with a generator capacity above 75 KW, to be more precise (150KVA = 120KW). Then it can be analyzed that the generator vibration falls into the category of "vibration within tolerance limits and is only operated for a limited time" where the highest speed is 11.99 mm/s.

Reusing Jet Grouting Waste as Filler for Road Asphalt Mixtures of Base Layers

Secondary raw materials consist of production waste or material resulting from recycling processes, currently in large quantities, which can be injected back into the economic system as new raw materials. This study proposes jet grouting waste (JGW) as filler for hot and cold asphalt mixtures applied as base layers of road pavements and investigates the physical and mechanical properties. JGW is derived from soil consolidation performed during underground roadway tunnel construction. The research compares three asphalt mixtures: (a) hot mixture containing limestone aggregate-filler (HMA), (b) HMA containing JGW (HMAJ), (c) cold recycled asphalt mixture containing JGW (CRAJ). Leaching tests of JGW and reclaimed asphalt pavement (RAP) were conducted; the best configurations of the three mixtures were determined by using the volumetric method through gyratory compaction. Three mastics with filler-to-binder ratios reflecting those of the asphalt mixtures were investigated through delta ring and ball test and frequency sweep test at 0.05% stress by using a dynamic shear rheometer. The morphology of each mixture was further investigated by scanning electron microscopy. The results showed that CRAJ with 28 days of curing time reached the indirect tensile strength (ITS) of HMA (0.73 MPa) within 14 days and, among all studied mixtures, returned the lowest cumulative strain, which was on average 30% lower than that of HMA and HMAJ. The results of this study have shown that the cold alternative mixture, CRAJ, promotes the reuse of two types of waste, RAP and JGW, as it fully meets the reference Italian Technical Standard and ensures good mixture performance in addition to conserving natural resources.

Recovery of Polluted Urban Stormwater Containing Heavy Metals: Laboratory-Based Experiments with Arlita and Filtralite

Heavy-metal sources in urban environments include automobile exhaust, fuel combustion, tires, road asphalt, weathering of building materials, and/or industrial activities. The presence of heavy metals in urban stormwaters constitutes a potential risk for water resources and aquatic life. Results from the present study demonstrated the effectiveness of two different lightweight aggregates (LWAs), Arlita and Filtralite, to remove heavy metals (Ni, Cu, Zn, Cd, and Pb) present in aqueous solutions. These materials were selected because they previously showed great results for water treatment and because of their physicochemical properties. The removal efficiency of the studied materials was evaluated with batch tests containing solutions contaminated with heavy metals (with individual and multiple contaminants) at different concentrations mixed with the LWA particles. Filtralite showed a better performance in heavy metal removal than Arlita: higher adsorption capacity for all metals, and lower release of metals from contaminated particles into washing water. The average removal capacities in tests developed with solutions containing individual contaminants for Arlita and Filtralite were 76% and 90%, respectively, although the values varied across the different contaminants. Metal elimination by LWAs was more effective with individual contaminated solutions than with multielemental ones. The analysis of the adsorption curves, the mineral precipitation on the LWA surface, and the geochemical modeling confirmed that two different mechanisms are responsible for the heavy-metal removal. First, the rough surface of the LWA presents sorbing surface sites of the forming minerals, resulting in the ion-exchange reactions of metal ions. Second, the LWA–water interaction causes an increase in solution pH, which triggers the precipitation and coprecipitation of the metals in the form of oxide and hydroxides. The study confirms that the use of Arlita and especially Filtralite present promising potential to remove heavy metals from urban stormwaters.