What is the typical ratio of cement to aggregate in a standard concrete mix?

The typical ratio of cement to aggregate in a standard concrete mix is 1:2:3, which refers to one part cement, two parts sand, and three parts gravel. This formulation is commonly used for general construction purposes and provides a good balance of strength and workability in the concrete.

In this mix design, the proportions ensure that the paste from the cement hydrates adequately with the aggregates to form a strong bond, resulting in a concrete that can withstand various loads and forces once cured. The specific ratio allows for effective distribution of aggregates, contributing to the overall durability and mechanical properties of the concrete.

The ratios in the other options do not represent the standard mix for general structural applications. For instance, the 1:1:2 ratio would likely lead to a weaker mix, as the cement proportion is higher relative to the aggregate than is typical for most construction needs. The 1:3:5 ratio dilutes the cement content too much, potentially causing inadequate strength. The 1:2:4 proportion is also used but is generally considered more appropriate for heavy-duty applications, such as pavements or structural foundations, rather than the general-purpose mix represented by the 1:2:3 ratio, which remains widely accepted for standard