Influence of Concrete Mix Proportions and Curing Regimes on Density, Absorption, and Voids in Hardened Concrete

The aim of this research is to assess the mechanical strength and durability performance of the concrete incorporating various contents of the ordinary Portland cement and w/c. Besides, it has been undertaken to study the effect of curing methods on compressive strength of the concrete as well as the physical properties, which are investigated in terms of density, absorption and volume of permeable voids as an (porosity). Many researchers consider these physical properties as an indicating signs on the permeability of the concrete, or in other words, they were as an indirect method to measure the permeability and to evaluate it. Five mixes are prepared and tested at the age of 28 days. The concrete specimens are cured in two different methods, in the first method specimens are moist cured while in the second method the specimens are air cured at 20 ̊C and 80% relative humidity to examine the effect of curing regimes. An experimental procedure for testing the physical properties of concrete is carried out according to ASTM (C 642-97). The results of the study showed that the increase of cement content and the reduction in the w/c leads to more durable concrete because of loss of absorption and porosity characteristics, in addition to that, higher density and compressive strength. Test results also showed that the water curing method have significant effect for improving the strength and durability performance of the concrete.