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Past work and current technical literature were reviewed to determine potential capping materials for expedient repair of small craters (less than 20 by 20 feet repair areas) in airfield pavements. Seven materials identified in the literature review were tested in the laboratory to develop information on their strength and cure requirements. Accelerated high alumina cement, magnesium phosphate cement, three commercial asphalt products and unsurfaced, well compacted aggregate were recommended for field testing as the most promising small crater repair materials. (Author).
Because of the nature of the hydraulic structures over which the Army Corps of Engineers has responsibility, there are frequent requirements to repair spalled or eroded concrete that is underwater, close to the waterline, or in areas from which it is difficult to divert flow or dry the concrete. This investigation evaluated the effectiveness of commercially available products in repair of concrete with wet surfaces. Slant-shear bond and compressive strength tests were conducted on each of the 22 materials recommended for repair of spalls in wet concrete. Based on the results of these screening tests, eight materials were selected for additional laboratory tests including: a) bonding capacity in direct tension; b) bonding capacity under flexural stress; c)resistance to abrasion; d) resistance to cycles of freezing and thawing; e) impact resistance; and f) thermal capability with concrete. Test results and material costs were used in developing a rating system to compare the relative performance of the various materials. Overall performance ratings indicate two materials, an epoxy and a cement-based product, were nearly equal in outperforming the other products tested. Which of these two materials is to be specified for a given repair will likely depend on the specific project requirements and critical material properties. Concrete repair. (edc).
The U.S. Air Force has conducted research and development work since the early 1960s to improve the capability to repair bomb damaged airfields. As part of the in-house testing for the Rapid Runway Repair (RRR) Program, the Air Force Engineering and Services Center (AFESC) has conducted Development, Test and Evaluation on interim systems for crater and spall repairs. The two interim crater repair methods, precast slab and fiberglass mat over crushed stone, were tested. The precast slab tests were conducted in two phases, using two generations of the slab technology. The fiberglass mat over crushed stone tests compared two different polyurethane resins for use in rainy or high water table conditions. In addition to these tests of the repair methods, a comparative test of compaction equipment performance was conducted. The final test series evaluated the proposed polymer concrete formulations for the interim spall repair system, including water-tolerant polyurethane, furfuryl alcohol, and magnesium polyphosphate.
The objective of the program discussed in this report was to provide the Air Force with a material for rapidly effecting the repair of damage to an operational airfield runway pavement. The investigation considered the use of gypsum-base fast-setting cements and accelerated portland cements. Data concerning mixing, use of aggregates, useful life and physical characteristics of selected gypsum cements were generated. The program resulted in two materials which can be placed and used as pavement repair in one hour or less, but which must be considered temporary and scheduled for replacement when time is not a controlling factor. A 'rule-of-thumb' guide is presented to aid in the design of a pavement repair. (Author).