13.2 : עיצוב לדוגמה: מחברים במדרכות בטון

The extension of an existing plain concrete pavement is proposed for construction using concrete slabs, ensuring minimal pavement cracking.

A pavement engineer decides to provide construction, expansion, isolation, and contraction joints to control pavement cracking.

The construction joints are gaps provided between the new slab and an existing slab to allow any possible movements in the new slab. Dowel bars embedded in the concrete tie the adjacent slabs together.

The expansion joints are gaps provided between adjacent slabs to allow concrete's thermal expansion.

Its construction involves arranging dowel bars in rows in the pavement's transverse direction and pouring concrete over the bars.

The gap left is then filled with compressible fillers and sealants.

Isolation joints are provided where the pavement encounters a manhole. A half-inch wide joint around the manhole, filled with a compressible material, forms the isolation joint.

Finally, the contraction joint is provided by sawing a groove in the recently hardened concrete pavement oriented perpendicular to the direction of traffic flow.

This helps to localize and control crack formation during concrete's contraction.