Which method is recommended to enhance the workability of concrete?

The approach of using non-porous and saturated aggregates while increasing the water-to-cement (w/c) ratio effectively enhances the workability of concrete. Non-porous aggregates can help reduce the absorption of water during mixing, ensuring that more water remains in the mix for achieving optimal workability. When the aggregates are saturated, the surface is already wet, which minimizes the need for additional mixing water to achieve desired consistency.

Increasing the w/c ratio can also improve workability, as more water makes the mixture less viscous and easier to handle. However, it is essential to balance this with the potential impacts on the strength and durability of the concrete, as too high a w/c ratio can lead to lower strength and increased porosity in cured concrete.

The other methods, such as decreasing mixing time and temperature, do not support the goal of enhancing workability. Additionally, using smaller irregular-shaped aggregate particles generally leads to a more difficult mix to manage, as it can negatively impact the overall flow and consistency of the concrete. Thus, option B provides a practical and effective strategy to improve workability in concrete mixes.