Influence of Chemical Composition of Cement types on Microstructural and Mechanical Concrete Properties
Abstract
Sulfate attack deteriorates concrete causing a series of problems that threaten the safety of the concrete structures and drains the financial resources in the repair process.Recently, to eliminate the impairment of concrete, it is preferable to use particular types of cement like sulfate-resistant cement (SRC) than ordinary Portland cement (OPC). The primary difference between OPC and SRC, which makes SRC a superior alternative, is the chemical composition. Clinker componentsareconsidered themain factor thataffects concrete deterioration. Components of the clinker are beliteC2S,alite C3S,ferrite C4AF, and aluminate C3A. Corrosion hydrate compounds that cause concrete impairment are calcium aluminate hydrate C-A-H, portlandite, gypsum, calcium silicate hydrate C-S-H, and ettringite. The presence of those erosion components depends upon percentages of C3S, C2S, C3A, and C4AF in the clinker.In this study paper, the Influence of using SRC on concrete mechanical characteristics was studied compared with OPC. Two concrete mixes with the same proportions using were cast for this purpose. Mechanical properties are investigated in compression, tensile, and flexural tests.In addition to the existence of the main phases of cement paste and the microstructure of the concrete sample wasinspected by scanning electron microscope SEM and X-ray diffraction XRD techniques. Outcomes obtained from XRD and SEM techniques and compression, tensile, and flexural tests assets visualization of the sulfate attack mechanism and presence of corrosion components. The results show that the chemical structure of concrete has SRC reduces the formation of erosion compounds; consequently, cracks, voids, concrete strength softening, and consuming basic phases of cement paste are eliminated.Furthermore, SRC compressive strengths increased by about 107%, 109%, and 115% compared to OPC at different test ages of 7 days, 28 days, and 90 days.
