ECTION 681 — SLABJACKING
681.1 DESCRIPTION —
This work is filling voids beneath existing rigid base courses or pavements and pressure-jacking the pavement or base course to grade with cement grout.
681.2 MATERIALS —
Section 679.2, modified as follows:
(f) Mix Design.
1 part cement (by volume)
3 parts pozzolan (by volume)
Admixtures—if required and accepted
Water — an amount such that the time of efflux is
within 16 to 26 seconds (ASTM-C939). A more fluid
mix with an efflux time of 10 to 15 seconds may be
used for the initial injection in each hole.
Use a stiffer mix, if the above mix fails to raise the pavement slab.
1. Drilling Holes.
Section 679.3(d)1. except penetration of the stabilized base may not be necessary.
Connect an expanding rubber packer to the discharge hose on the grout pump and lower into the holes. Do not extend the discharge end of the packer below the lower surface of the concrete pavement. When jacking continuously reinforced concrete pavement, pump in a pattern and in the amount required to raise the pavement to within 0.02 foot, ±, from a string line grade, or as directed. When jacking jointed slabs of concrete pavement and bridge end slabs, pump in a pattern and in the amount required to raise the pavement to within 0.03 foot, plus or minus, from a string line grade, or as directed.
Continuous pressures to 200 psi will be permitted. Pressure to 300 psi will be allowed only for short periods, except in the event the pavement is bonded to the subgrade, brief pressure rises to 600 psi will be allowed.
Bring pavement, raised above the tolerances listed above, to grade by grinding. If the overjacking is greater than 0.10 foot, satisfactorily remove and replace the pavement in accordance with Section 501 at not cost to the Department.
5. Radial Cracks.
6. Transverse Cracks.
7. Hole Patching.
681.4 MEASUREMENT AND PAYMENT —
(a) Holes Drilled.
(b) Grout Material.
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