UFC 3-260-02
30 June 2001
CHAPTER 9
PAVEMENT MATERIALS
1. GENERAL. This chapter provides the designer an overview of pavement materials that might be
used in military airfield pavements. This overview will include soil and aggregate stabilization, asphaltic
concrete, portland cement concrete, and recycled materials. More comprehensive and detailed
descriptions, policy, and guidance on uses and limitations, testing requirements, suitable materials,
mixture proportioning, and construction can be found in TM 5-822-14/AFJMAN 32-1019 for stabilization,
TI 822-08/AFMAN 32-1131 V8(1)/DM 21.11 for asphalt concrete, and TM 5-822-7/AFM 88-6, Chapter 8,
for portland cement concrete. In addition, each service also maintains recommended guide
specifications for these materials that the engineer can edit for specific jobs. Materials technology
evolves constantly, and new guidance on pavements materials is available from HQUSACE (CEMP-ET),
appropriate Air Force MAJCOM pavements engineer, or Naval Facilities Engineering Service Center as
changes develop. This chapter is a short overview to aid the designer during the design process, and
the more comprehensive guidance documents noted above should be consulted concerning each
service's specific limitations and requirements for these materials and for preparing individual project
specifications.
2. STABILIZATION. . Existing soils or aggregates may not be suitable for use in airfield construction
(e.g., poor grading, low strength, or excessive plasticity) or may have other undesirable characteristics
(e.g., tendency to shrink or swell with moisture content changes). By stabilizing such materials with
appropriate additives, their engineering and construction properties can be improved. Lime, portland
cement, and asphalt are the most common stabilizers, but pozzolans (notably fly ash), ground
granulated blast furnace slag, and a wide variety of proprietary materials are also available. TM 5-822-
14/AFJMAN 32-1019 provides official guidance on use of lime, portland cement, lime-fly ash, and
bituminous materials for stabilization. HQUSACE (CEMP-ET), appropriate Air Force MAJCOM
pavements engineer, or Naval Facilities Engineering Service Center should be consulted for assistance
on use of other stabilizers and conditions not covered in the existing guidance.
a. Purpose. Stabilization is most commonly associated with achieving strength to reduce
pavement thickness requirements. However, other equally important and perhaps even more important
uses of stabilization include improvement in soil workability, prevention of pumping in rigid pavements,
mitigation of adverse volume changes in expansive soils, providing a construction platform to ease and
speed construction operations, reduction of effects of adverse weather during construction, and allowing
use of an economical local material that fails conventional specifications in lieu of importing more
expensive materials from elsewhere.
b. Requirements. Subsequent chapters in this manual provide detailed guidance on how to
incorporate stabilized materials in each of the different thickness design methods for flexible and rigid
pavements. To qualify for a reduced thickness in these design methods, the stabilized material must
achieve a compressive strength of not less than 5.17 MPa (750 psi) for base courses in flexible
pavements, 3.45 MPa (500) psi for base courses in rigid pavements, and 1.72 MPa (250) psi for flexible
pavement subbases for the Army and Air Force or 1.03 MPa (150 psi) for subbases for the Navy. These
strengths are determined after 7 days of curing at 22.8 oC (73 oF) for portland cement and after 28 days
of curing at 22.8 oC (73 oF) for lime, slag, and combinations with pozzolanic materials (e.g., lime-fly ash
mixtures). In addition to strength, there are specific requirements for durability and material properties
that must also be met. Even if a material fails to qualify for the reduced pavement thickness
requirements, stabilization may prove desirable for some of the other reasons noted above. If
9-1
Previous Page
