Cementitious Material Crushing

The top-down crushing damage in cementitiously stabilized materials is driven by vertical compressive stress. The model for the crushing life is:

where N_f is the crushing life,

          k₄ and k₅ are model parameters that depend on the material type,

          r is the maximum dry density of the material in lbs/ft³,

          wc_opt is the optimum moisture content in percent,

          s_c is the vertical compressive stress at the top of the layer, and

          UCS is the current unconfined compressive stress after accounting for curing.

Once the crushing life is determined for each axle load, the crushing damage w_c is accumulated the same way as cementitious fatigue damage, following Miner’s Law, but damage is updated after every set of loads following the incremental-recursive procedure in CalME. The stiffness is then reduced by a ratio SR_curing, which is determined using the same equation as cementitious fatigue damage.