Pavement classification – where does cement grouted (grouted macadam) pavement fit? Cement grouted or grouted macadam pavements are generally classified as which type of pavement for design and performance considerations?

Introduction / Context:
Modern pavements are classified by how they distribute wheel loads: flexible (bituminous), rigid (cement concrete), and semi-rigid systems. Cement grouted or grouted macadam pavements involve a dense aggregate skeleton with voids partly filled by cement grout, producing properties between flexible and rigid layers.

Given Data / Assumptions:

• Pavement layer consists of a bituminous or open-graded aggregate matrix later grouted with cement slurry.
• Resulting composite has higher stiffness than standard bituminous layers but is not a monolithic slab.
• Design aims at improved rutting resistance and load spreading with reduced slab action compared to rigid concrete.

Concept / Approach:
Semi-rigid pavements combine a load-spreading granular/bituminous skeleton with a cementitious grout that boosts modulus and reduces deformation, yet they do not behave like fully jointed or continuously reinforced concrete slabs. Their temperature sensitivity and crack patterns differ from rigid pavements, while their deflection response is smaller than flexible systems.

Step-by-Step Solution:

Verification / Alternative check:
Layer modulus values and typical strain profiles under load for grouted macadam confirm intermediate behavior: tensile strains at the bottom of the layer are reduced compared to flexible pavements but not eliminated as in rigid slabs.

Why Other Options Are Wrong:
Rigid pavement implies monolithic concrete slab action. Flexible pavement lacks the cement grout that significantly increases stiffness. Composite in the strict sense usually refers to a rigid concrete over flexible or vice versa, not grouted macadam.

Common Pitfalls:
Assuming joints and slab curling behavior as in rigid pavements; overlooking curing and grout penetration quality which govern performance.

Final Answer:
Semi-rigid pavement