Theoretical-Experimental Aspects of Determining Concrete Strength

Concrete strength is the property most valued by designers and quality control engineers. In rigid bodies, there is an inverse relationship between porosity (volume fraction of voids) and strength. Consequently, in multi-stage materials such as concrete, the porosity of each microstructure component can become limiting in durability. Natural aggregates are generally dense and strong; hence, it is the porosity of the hydrated cement paste and the interface transition zone between the matrix and the hard aggregate that usually determines the characteristic strength of normal weight concrete. Although the water-cement ratio is important in determining the porosity of the matrix composition and the interface transition zone and the strength of the concrete, factors such as compaction and curing conditions (degree of hydration of the cement), aggregate size and mineralogy, types of admixtures of mixtures, geometry and humidity conditions, types of stresses and load rate can have an impact on strength. In this paper will be explained in detail, the impact of several factors on the strength of concrete. While uniaxial compressive strength is generally accepted as the general concrete strength index, the relationships between compressive uniaxial strength and other strengths such as tensile, bending, shear, and biaxial strength are discussed.   Received: 27 September 2022 / Accepted: 26 November 2022 / Published: 20 December 2022