When damaged, military airfields must be repaired quickly so that flying operations can resume. Due to their rapid-setting and high-strength properties, epoxy-based polymer concretes (PC) may provide a good alternative to the portland cement concrete (PCC) rapid repair mixes currently used by the United States Air Force (USAF) for their Rapid Airfield Damage Recovery (RADR) operations. Epoxy-based PCs use epoxy polymers in place of portland cement to bind together aggregate and form the composite concrete.
A commercially available epoxy-based PC, referred to as Commercial Product "B" in this thesis, was tested according to the procedures stated in the Tri-Services Pavements Working Group (TSPWG) Manual M 3-270-01.08-2. This manual defines testing protocol to be used for rapidsetting rigid repair materials intended for use on rigid airfield pavement spall repairs. These tests include various ASTM standards for compressive strength, flexural strength, slant-shear bonding strength, modulus of elasticity, coefficient of thermal expansion, and slump.
Commercial Product "B" was not able to set and cure within the time limits set by the TSPWG manual, but otherwise surpassed final compressive strength, flexural strength, slant-shear bonding strength, and slump requirements. However, its modulus of elasticity was below the acceptable range, and its coefficient of thermal expansion was several times higher than the maximum allowed value.
In addition, a second epoxy-based PC currently under development by Luna Labs and D.S.
Brown was tested for compressive strength and, in most mix designs, surpassed the minimum requirements. This PC was also field tested in a series of four (4) 2-feet by 2-feet by 8-inch deep patches placed within an 8-inch thick PCC slab. Three of these patches did not meet minimum compressive strength requirements and none of them exhibited good bonding between the PC repair material and the original PCC slab.
Finally, the effect of the surface moisture content of PCC on the bonding strength and chloride ion penetration resistance when PCC is bonded to PC was tested by casting Commercial Product "B" against ordinary PCC under two different moisture conditions: surface saturated dry (SSD) and PCC that had been conditioned at 10% relative humidity (RH) for 48 hours. The bonded samples underwent three- and four-point bond flexural testing and rapid chloride penetration testing (RCPT). The bond flexural testing showed that Commercial Product "B" bonds to PCC better when the PCC has been conditioned at 10% RH rather than being at SSD conditions. No statistically significant difference was detected for RCPT between bonded samples cast under the two surface moisture conditions, but did show that samples of PCC bonded with Commercial Product "B" are less susceptible to chloride ion penetration than samples comprised entirely of PCC.
The results of this thesis show that PC may be useful to the USAF for repair airfields as short term repairs, but further work is required to ensure they meet all standards set by TSPWG for rapid repair materials. They also demonstrate that, when possible, a PCC repair surface should be dried completely before PC repair material is cast against it. / Master of Science / When damaged, military airfields must be repaired quickly so that flying operations can resume. Due to their rapid-setting and high-strength properties, epoxy-based polymer concretes (PC) may provide a good alternative to the portland cement concrete (PCC) rapid repair mixes currently used by the United States Air Force (USAF) for their Rapid Airfield Damage Recovery (RADR) operations. Epoxy-based PC use epoxy polymers in place of portland cement to bind together aggregate and form the composite concrete.
To test whether epoxy-based PC can be used for RADR or other airfield repair operations, a commercially available epoxy-based PC, titled Commercial Product "B" in this thesis, underwent a battery of tests as specified for potential rapid repair materials in the Tri-Services Pavements Working Group (TSPWG) manual for testing protocol for rapid-setting rigid repair materials.
Commercial Product "B" was not able to set and cure within the time limits set by the TSPWG manual but otherwise surpassed final strength, bonding, and workability requirements.
However, it is not nearly as stiff as ordinary PCC and it expands and contracts far more than PCC when it undergoes temperature changes.
In addition, a second epoxy-based PC currently under development by Luna Labs and D.S.
Brown was tested for compressive strength and, in most mix designs, surpassed the minimum requirements. This PC was also field tested in a series of four (4) patches placed within a PCC slab. Three of these patches did not meet minimum compressive strength requirements and none of them exhibited good bonding between the PC repair material and the original PCC slab.
Finally, the effect of the surface moisture content of PCC on the bonding strength and resistance to chloride ions, often found in de-icing agents, when PCC is bonded to PC was tested by casting Commercial Product "B" against ordinary PCC under two different moisture conditions:
surface saturated dry (SSD) and PCC that had been conditioned at 10% relative humidity (RH).
The bonded samples underwent bond flexural testing and rapid chloride penetration testing (RCPT). The bond flexural testing showed that Commercial Product "B" bonds to PCC better when the PCC has been conditioned at 10% RH rather than being at SSD conditions. No statistically significant difference was detected for RCPT between bonded samples cast under the two surface moisture conditions but did show that samples of PCC bonded with Commercial Product "B" are less susceptible to chloride ion penetration than samples comprised entirely of PCC.
The results of this thesis show that PC may be useful to the USAF for repair airfields as short term repairs, but further work is required to ensure they meet all standards set by TSPWG for rapid repair materials. They also demonstrate that, when possible, a PCC repair surface should be dried completely before PC repair material is cast against it.
| Identifer | oai:union.ndltd.org:VTETD/oai:vtechworks.lib.vt.edu:10919/116537 |
| Date | 24 October 2023 |
| Creators | Atwood, Paul |
| Contributors | Civil and Environmental Engineering, Brand, Alexander S., Flintsch, Gerardo W., Case, Scott W. |
| Publisher | Virginia Tech |
| Source Sets | Virginia Tech Theses and Dissertation |
| Language | English |
| Detected Language | English |
| Type | Thesis |
| Format | ETD, application/pdf |
| Rights | In Copyright, http://rightsstatements.org/vocab/InC/1.0/ |
Page generated in 0.0062 seconds