Enhancing Concrete Strength and Microstructure with Basalt and Steel Fibers in Acid and Base Environments Incorporating Desert Sand

Abstract Concrete is widely used in construction due to its remarkable compressive strength and durability. However, its performance can deteriorate when exposed to harsh environmental conditions, such as acidic or alkaline surroundings. There has been considerable interest in incorporating both basalt and steel fibers (B&SFs) to enhance the resilience of concrete in such challenging settings. This study presents a comprehensive examination of the influence of B&SFs on the strength and microstructure of concrete, utilizing desert sand as a fine aggregate and subjecting it to exposure to acidic and alkaline environments. Employing a systematic experimental approach, this research assesses concrete samples with varying B&SFs proportions. The study encompasses density and compressive strength tests, complemented by microstructural analyses using scanning electron microscopy (SEM) and X-ray diffraction (XRD), to analyze the performance of the concrete under diverse environmental conditions. Initial findings indicate that including B&SFs results in a substantial improvement in concrete strength. The role of basalt fibers (BFs) in enhancing the concrete's resistance to acidic environments by mitigating deleterious effects on microstructural integrity is particularly noteworthy. Notably, when exposed to acidic conditions, concrete mixtures containing 0.5% BFs demonstrated the least strength loss. When B&SFs are synergized, their positive effects are amplified, yielding concrete with exceptional resistance to alkaline environments. Microstructural analysis reveals that incorporating fibers refines and strengthens the interconnected matrix of cementitious products, thereby enhancing cohesion and overall strength. Furthermore, this study underscores that desert sand can be a viable alternative to traditional fine aggregates without compromising concrete resistance if it is appropriately reinforced with fibers. In conclusion, this research sheds light on the promising role of B&SFs in augmenting the strength and microstructure of concrete containing desert sand.