Road Base Stabilization Research Studies

"Stabilization projects are almost always site-specific, requiring the application of standard test methods, along with fundamental analysis and design procedures, to develop an acceptable solution. As with any such process, adherence to strict environmental constraints is vital to project success. The use of cementitious materials makes a positive contribution to economic and resource sustainability because it allows enhancement of both standard and substandard in situ soils to levels consistent with the requirements of a given application."

"This study concluded that the improvements to key properties of cold mix by the addition of Portland Cement can be explained by a range of mechanisms, including improved rate of emulsion coalescence after compaction, cement hydration and enhancement of binder viscosity."

"The Federal Aviation Administration requires the use of stabilized bases for all pavements that will be required to support aircraft weighing 45,350 kg (100,000 lbs) or more. literature review was performed to determine the current state of the art in terms of understanding stabilization mechanisms, design procedures, and considerations. were collected to provide a review of the performance of many pavements at high-volume airports that support heavy aircraft loads. Field data collected included structural data in the form of nondestructive testing (NDT) performed with a falling weight deflectometer, visual condition survey using the pavement condition index (PCI) procedure, and construction and maintenance history data. The NDT was evaluated to determine modulus values for the various pavement layers. he PCI data were compared to historic PCI data to determine trends in performance. he construction and maintenance history records were reviewed to determine rehabilitation efforts required to maintain the pavements at appropriate levels."

"Complete excavation of frost-susceptible material is not economically viable in all cases. Emulsion mixes have been used successfully to follow roadbed soil movement without cracking. Laboratory and field observations indicate that emulsion mixes have membrane-like mechanical properties rather than the slab-like properties of standard hot bituminous mixtures. Furthermore, emulsion mixes are not as susceptible to thermal cracking as regular standard hot bituminous mixtures." 

Stabilized road gravel was tested to compare with that of unaltered raod gravel. " California bearing ratio (CBR), resilient modulus (M_r) , and unconfined compression (q_u) tests were conducted on road surface gravel alone and the fly-ash stabilized road surface gravel samples prepared in the field to evaluate how addition of fly ash improved strength and stiffness.  After 7 days of curing, the stabilized road surface gravel compacted in the field from a field-mix sample had CBR ranging between 48 and 90, M_r between 96 and 125 MPa, and q_u between 197 and 812 kPa, whereas the road surface gravel alone had CBR of 24, and M_r of 51 Mpa."

The objectives of this Texas DOT funded study were to provide an update to the current TXDOT mixture design specification based on comprehensive laboratory testing and develop and calibrate a new generation fatigue performance model that accounts for strength and shrinkage cracking potential of cement treated aggregate base and subgrade soils.

Washington Ave. in Las Vegas, Neveda was distresses such that reconstruction was needed. The existing pavement consisted of 4.5 to 7 inches of asphalt pavement over 13.5 to 18.5 inches of granular base. The conventional design would have consisted of removal of the asphalt and base material and replacement with 18 inches of granular base and 6 inches of asphalt. An alternative method was selected using base stabilization with emulsified asphalt. The alternate design consisted of removal of the asphalt pavement and in-place stabilization with 5% emulsified asphalt of the upper 6 inches of the existing base followed by 5 inches of new asphalt. The alternate design saved the city an estimated $323,000, a 30% savings. Construction days were reduced from an estimated 120 days to 40 days and 3,000 fewer loads of materials were trucked on and off the project.