APPENDIX-B
GENERAL REPAIR PLAN FOR CRACKS IN CONCRETE STRUCTURES
1. Introduction
This report outlines a comprehensive repair plan for addressing cracks in concrete structures, adhering to
the guidelines set forth in ACI 301-20. The plan details essential steps necessary to effectively repair concrete
cracks while ensuring compliance with industry standards.
2. Scope of Work
The scope of work includes the following key activities:
a) Identification of Affected Areas: Conduct a thorough assessment to identify specific areas requiring
repair, focusing on all visible cracks in beams, slabs, and walls.
b) Documentation of Cracks: Document the extent and severity of each identified crack, recording
measurements, locations, and any observed structural implications. This documentation should
include photographic evidence for reference.
3. Materials and Specifications
A. Repair Materials
Selecting appropriate repair materials is crucial for the effectiveness of the repairs. The following options
are recommended based on the type and cause of the cracks:
a) Epoxy Resins: Ideal for structural repairs and bonding, providing high strength and low viscosity.
b) Polymer-Modified Mortars: Suitable for resurfacing and filling larger cracks, offering improved
adhesion and flexibility.
c) Flexible Sealants: Recommended for sealing non-structural cracks, allowing for movement while
maintaining a watertight seal.
B. Compliance
Ensure all selected materials meet the requirements outlined in ACI 301-20, focusing on material properties,
performance, and long-term durability.
4. Surface Preparation
A. Cleaning
Effective surface preparation is essential for successful repairs. The following cleaning methods should be
employed:
a) Debris Removal: Use compressed air, wire brushes, or pressure washing to remove loose debris,
dirt, and contaminants from the crack surfaces.
b) Surface Assessment: Inspect the crack surfaces for any underlying issues that may require additional
treatment before repair.
B. Preparation of Crack Edges
For larger cracks, it is recommended to route the crack to create a uniform profile that enhances bonding.
Refer to ACI 503R-16 for specific surface preparation techniques.
5. Crack Repair Methods
A. Active Cracks
a) Epoxy Injection:
i. Employ epoxy resins to fill and bond the crack, following the manufacturer's instructions
for mixing and application.
ii. Begin injection from the bottom of the crack and work upward to ensure complete filling
without air pockets.
b) Monitoring: Install crack monitors to assess future movement and evaluate the effectiveness of the
repair.
B. Dormant Cracks
a) Routing and Sealing:
i. Route the crack to a width of at least ¼ inch, ensuring clean edges for optimal adhesion.
ii. Fill the routed crack with a flexible sealant that is compatible with concrete.
b) Overlay: For extensive areas, consider applying a polymer-modified overlay to improve both
aesthetics and surface integrity.
