CONCRETE REPAIR AND REHABILITATION SECTION 628
Non -Shrink Grout Horizontal Sloped Vertical ≥ 1” All Trowel
2.Low Viscosity Epoxy or High Molecular Weight Methacrylate
a.Remove surface contaminants by blowing out the crack with oil -free compressed air.
b.Prepare the surface and damming material per manufacturer recommendation. Take
measures to prevent sealing material leakage when a crack has propagated to a non - horizontal surface.
c.Perform repairs when surface and ambient temperatures are within the manufacturer
recommended ranges.
d.Mix material components in accordance with the manufacturer’s recommendations.
e.Apply sealing material in accordance with the manufacturer’s recommendations.
f.Cover surface areas where excessive sealing material remains with a light broadcast of dry
mortar sand that complies with Section 1003 at the time recommended by the manufacturer. Use a quantity of sand necessary to absorb the excess sealing material.
g.Following all manufacturer curing methods and recommendations prior to opening to traffic.
3.Polyurethane or Silicone
a.Seal cracks in horizontal surfaces with self -leveling sealant. Seal all other surfaces with non -sag
sealer.
b.Rout cracks by grinding to create a V -shaped groove with the crack centered in the groove.
Routed grooves must be a maximum 1/2 -inch depth.
c.Remove contaminants by blowing out crack with oil -free compressed air.
d.Ensure the ambient and surface temperatures are within the manufacturer’s recommended
placement range before applying the sealant.
e.If required, apply primer as recommended by the manufacturer.
f.Apply sealant in accordance with manufacturer's recommendations to form a smooth surface.
g.Cure sealant in accordance with the manufacturer’s recommendations. Curing must be
completed prior to opening to traffic.
4.Non -Shrink Grout.
a.Tool the crack to create a dovetail slot that is a minimum 1 -inch depth with a base and at least
1/4-inch greater than the crack width
b.Remove contaminants from the tooled crack by blowing the crack out with the oil -free
compressed air or by pressure washing.
c.Ensure that the ambient and surface temperatures conform to the manufacturer’s
recommendation during grout mixing, placement, and curing. CONCRETE REPAIR AND REHABILITATION SECTION 628 341 d. Non -shrink grouts that do not contain a pre -mixed bonding agent require application of an epoxy bonding agent the conforms to AASH TO M235 Type V or latex bonding agent that conforms to ASTM C1059 Type II to all surfaces that are in contact with the repair grout. The epoxy bonding agent must comply with Section 628. 3.4.C and be applied in accordance with the manufacturer’s recommendations.
e.Mix non -shrink grout in accordance with the manufacturer’s recommendation to a dry -pack
consistency.
f.Apply non -shrink grout by troweling the material into the tooled crack in approximately 1/2 -
inch lifts. Tamp each lift with a wood or steel tool that will fit into the crack. Trowel the final lift flush with the concrete surface. Cracks in sloped or ver tical surfaces require form placement after troweling to prevent material sagging.
g.Cure in accordance with manufacturer recommendations.
628.3.3 Non -Shrink Grout Repair.
A.Repair non -shrink grout used to fill shear keys between precast concrete elements, or various
pockets and voids associated with precast concrete elements, as follows:
1.Remove deteriorated grout in accordance with Section 628. 3.4. taking care not to damage the
adjacent precast concrete elements. If damage occurs, repair concrete in accordance with
2.Clean the concrete surface by blowing off dust and debris with oil -free compressed air.
3.Wet the concrete surfaces before placing grout. Do not allow standing water to remain in the
area receiving grout.
4.During grout placement, prevent falling material from reaching the roadway, waterway, or
railroad area below.
5.Prepare, place, and cure in accordance with the manufacturer’s recommendations.
628.3.4 Spall and Delamination Repair.
A.Limitations .
1.This section does not apply to prestressed elements or bridge decks
B.Definitions :
1.Shallow spalls are spalls that do not extend below the top mat of reinforcement.
2.Deep spalls are spalls that extend below the top mat of reinforcement.
3.PCC masonry rehabilitations are deep -spall patches that exceed the 0.5 cubic yard threshold in a
single area.
C.Materials .
1.PCC for shallow spall repairs shall comply with Section 1023.
2.PCC for deep spall repairs shall comply with Section 1022. Use Class A concrete in compliance
with Table 1022 .9-1.
3.Epoxy bonding agents shall conform to AASHTO M235 Type V.
a.Use Grade 2 epoxy on horizontal level surfaces.
Source: Delaware Standard Specifications for Road and Bridge Construction, 2025 Edition. Pages 350–351 of 779.