What does unconfined compressive strength measure in aggregate bases?

Unconfined compressive strength (UCS) specifically measures the load-carrying capacity and stability of aggregate materials when subjected to compressive forces without any confinement. In the context of aggregate bases used in construction and road building, this measurement is crucial because it provides insights into how well the material can withstand loads from traffic and structures above it.

A higher UCS value indicates that the aggregate base can resist deformation and failure under load, which is essential for ensuring the stability and longevity of pavements and other structures. This property is particularly important when designing and evaluating the performance of road bases and sub-bases, as it directly relates to the material's ability to support loads without collapsing or excessive settling.

The other choices do not relate to the unconfined compressive strength measurement. Water drainage efficiency pertains to how well water can move through the material, which does not directly tie into UCS. Temperature effects on aggregates might affect the material properties but are not measured by UCS. Particle size distribution is important for determining the overall quality and suitability of aggregates, yet it is a different property that does not measure load-carrying capacity directly.