Resumo em Inglês:

Abstract The study investigates the integration of alternate fine aggregates like Manufactured sand (MS), Crushed Rock Fines (CRF), Eco Sand (ES) into high-performance concrete M75 grade mixes, along with the inclusion of Alccofine 1203 admixture and glass fibers. It explores various replacement levels of the fine aggregates and evaluates the impact of adding Alccofine 1203 and alternate fine aggregates on the concrete performance. Alccofine 1203, a supplementary cementitious material, replaces a part of the binding component in concrete and enhancing the strength and durability properties and also mitigate the alkali-silica reaction. The incorporation of glass fibers improves concrete’s bending and tensile strength. The concrete mixes were carefully designed to meet specific strength and durability requirements. A comprehensive testing regimen assessed both fresh and hardened concrete properties, offering insights into overall quality and performance. This research work found that a high-performance concrete mix with 80% crushed rock fines and 20% eco sand exhibited superior strength and durability. Using crushed rock fines not only increased strength, especially when combined with Alccofine 1203, enhanced the strength and also reduced costs associated with manufactured sand. This combination of alternate fine aggregates in concrete mixes can contribute to sustainable construction practices, cost savings, improved concrete performance and regulatory compliance with environmental standards. Strength properties were validated using the Response Surface Methodology (RSM) Model, which evaluates the relationships between variables and concrete strength characteristics. Comparing measured strengths with the model validated predictions and provided insights into concrete mix performance.

Resumo em Inglês:

ABSTRACT The objective of this work is to study the behavior of corrosion in reinforced concrete slabs from the point of view of geostatistics. To this end, measurements of electrochemical potentials (reinforcement corrosion potentials) were taken in regions of a reinforced concrete slab, which was divided into smaller areas of the same dimensions in the “x” and “y” directions, respectively. In order to make the study feasible, a sub-region of this slab was separated where the corrosive activity was already more aggressive and the variograms were calculated for the “x” and “y” directions, according to the distances from the measurement points. After a detailed analysis of the results and the creation of graphs for each axis, the equations that best fitted the curves were obtained, in particular the polynomial for the “x” direction and the logarithmic for the “y” direction. From the data obtained, it is possible to understand the spatial extent of the problem, identify the corrosion bands in which each region of the structure studied is located and know the zone of influence of the sub-region used for analysis. The results can be used to choose the best technique for mitigating and combating slab corrosion, as well as for future work.

Resumo em Inglês:

Abstract This paper explores the use of novel lightweight concrete as an alternative material, focusing on Cellular Lightweight Foam Concrete (CLFC), renowned for its strength, low weight, thermal insulation, and sustainability. The study encompasses a thorough review of literature focusing on the evolution of lightweight concrete, experimental investigation including mix design variations and mechanical property analysis, statistical analysis using MINITAB software, SEM and EDS interpretation, and construction of model POD. Regression analysis was performed to investigate on the factors influencing compressive strength, revealing significant predictors such as cement, fly ash, water, and density, paving the way for enhanced concrete mixes. Characterization studies such as SEM and EDS were performed to analyse the formation of elements that contribute to the strength parameter. Moreover, the study underscores the potential of utilizing steam curing cycle to achieve early compressive strength in concrete mixes. Ultimately, the research aims to revolutionize construction practices by advocating for the widespread adoption of CLFC and innovative construction techniques to meet the demands of low-cost, eco-friendly housing.