Job Mix Formulation for Bituminous Concrete Grade II Using C# Programming

Bituminous Concrete mix design is a complex process and different methods are proposed by a number of researchers. Marshall’s method of mix design is one such process, which became very popular among the practitioners in India and elsewhere. SUPERPAVE method of mix design which takes into account climatic and traffic factors for aggregate and binder selection. It has gained its prominence and is observed to be superior to any other well-known mix design processes. Aggregate gradation adopted for the mix design plays a crucial role in the performance of the mix. Many researchers have developed mechanisms to work out Job Mix Formulations (JMF) so as to reach the appropriate aggregate mix in the field.The analytical phase of JMF deals with the method of blending of aggregates from the identified stockpiles in order to fulfill the requirements of gradation as specified by agencies for a given layer of flexible pavements. Methods proposed for aggregate blending includes the graphical methods, trial and error method and optimization techniques. The aim of these techniques is two-fold; the first is to optimize the cost involved in blending from the known unit cost of individual stockpiles; and the other is to fulfill the gradation recommendations of the local agencies and parameters suggested in other methods. In this research, an attempt has been made to develop C# (C-Sharp) application in .NET framework using the sequential search technique to work out the best blend of aggregate particles by ensuring the requirements mentioned in MoRTH’s (Ministry of Road Transport & Highways, India) recommended practice. Bailey’s method and the maximum density line have been recommended in 0.45 power chart and incorporating optimization criteria. Grade II bituminous concrete has been chosen for the research. It was clearly observed that the fine aggregate fraction in the stockpiles influences the final Job Mix Formulation. The devleloped tool can accommodate up to 5 stockpiles. It was also observed that the Bailey’s requirements are more stringent when compared with MoRTH requirements as far as JMF is considered. The developed tool is capable of generating the blends with Recycled Asphalt Pavement (RAP) aggregate blends

Empirical investigation to explore potential gains from the amalgamation of Phase Changing Materials (PCMs) and wood shavings

The reduction of gained heat, heat peak shifting and the mitigation of air temperature fluctuations are some desirable properties that are sought after in any thermal insulation system. It cannot be overstated that these factors, in addition to others, govern the performance of such systems thus their effect on indoor ambient conditions. The effect of such systems extends also to Heating, Ventilation and Air-conditioning (HVAC) systems that are set up to operate optimally in certain conditions. Where literature shows that PCMs and natural materials such as wood-shavings can provide efficient passive insulation for buildings, it is evident that such approaches utilise methods that are of a degree of intricacy which requires specialist knowledge and complex techniques, such as micro-encapsulation for instance. With technical and economic aspects in mind, an amalgam of PCM and wood-shavings has been created for the purpose of being utilised as a feasible thermal insulation. The amalgamation was performed in the simplest of methods, through submerging the wood shavings in PCM. An experimental procedure was devised to test the thermal performance of the amalgam and compare this to the performance of the same un-amalgamated materials. Comparative analysis revealed that no significant thermal gains would be expected from such amalgamation. However, significant reduction in the total weight of the insulation system would be achieved that, in this case, shown to be up to 20.94%. Thus, further reducing possible strains on structural elements due to the application of insulation on buildings. This can be especially beneficial in vernacular architectural approaches where considerably large amounts and thicknesses of insulations are used. In addition, cost reduction could be attained as wood shavings are significantly cheaper compared to the cost of PCMs

Sustainable benchmarking of a public transport system using analytic hierarchy process and fuzzy logic: a case study of Hyderabad, India

To achieve a well-balanced sustainable public transport system in an Indian scenario, a thorough performance assessment and benchmarking of existing systems in conventional and sustainable dimensions is necessary. Although institutionalisation of sustainable benchmarking of public transport systems is habituated across the globe, it is not largely practised in India. Based on this, we aim at developing a comprehensive mode-specific benchmarking framework for the urban bus system under Indian conditions with a case study of Hyderabad city. The developed framework consists of 29 evaluators structured into eight indicator groups. As the significance of these indicator groups and evaluators varies in the framework, the same has been determined by an expert opinion survey by applying multi-criteria decision-making techniques such as ‘analytic hierarchy process’ and ‘direct weighting.’ The assessment revealed that the overall performance of the urban bus system is approximately 70%. The parameters associated with the sectors of ‘passenger information systems’ and ‘social sustainability’ were found to underperform and required improvement. A better performance was observed among the service- and quality-oriented sectors. The associated intangibility in weighting and ranking during the process of benchmarking was addressed through the application of a fuzzy logic technique, and the ‘overall normalised rate of performance’ of the urban bus system was determined to be 74%. Based on these factors, the present study achieves a successful development and application of mode-specific benchmarking of public transport systems in the Indian context

Durability performance of alkali-activated concrete with pre-treated coarse recycled aggregates for pavements

Abstract This study examines the effect of coarse recycled aggregates (CRAs) and processed coarse recycled aggregates (PCRAs) on the behaviour of alkali-activated concrete (AAC) before and after exposure to marine seawater and acidic environments (5% HCl and 5% H2SO4 solutions). Measurements of compressive strength and the microstructure changes were conducted over periods of 56 and 90 days to assess these effects. The experimental design included varying the replacement levels of NAs with CRAs and PCRAs from (0–100%) and using ground-granulated blast furnace slag and fly ash as constant components. In addition to durability tests, sorptivity assessments were conducted to gauge the material’s porosity and water absorption capabilities. Advanced microstructure techniques, such as scanning electron microscopy (SEM) and X-ray diffraction (XRD), were employed to detail the pre and post-exposure mineralogical and microstructural transformations within the AAC blends. The AAC mixtures incorporating PCRAs emerged as durable, showcasing better strength and a denser, more compact matrix facilitated by the synergistic formation of NASH and CASH gels after exposure to aggressive agents compared to untreated CRAs. In addition, the results show that the samples exposed to marine seawater exhibited improved mechanical performance compared to those exposed to acidic environments. The novelty of this study lies in its exploration of the effects of recycling plant-based CRAs and PCRAs on AAC for marine and acid exposure