Frost Action On Roads And Railroads

Paper 1: The experimental uses are described of a Benkelman beam with a Helmer recorder attached as a means of measuring the changes in load-carrying capacity of flexible pavements that occur as a result of frost action. Paper 2: A comprehensive theory to explain rhythmic ice banding, which produces frost heave in soil, is presented. Paper 3: To promote a better understanding of the icing phenomenon, the icing theory is presented. Paper 4: This paper describes some of the manifestations of frost action which have proved troublesome from the standpoint of railroad maintenance in the Labrador Peninsula and also reports the results obtained from a number of ground temperature installations.

Summaries of papers presented.

Vol. 1: Findings from a six-year field and laboratory program of frost-action research in four principal areas are summarized. Research on the first topic, frost-susceptibility index tests, led to selection of the Corps of Engineers' frost design soil classification system as a useful method at the simplest level of testing. At a much more complex level, a new freezing test combined with a CBR test after thawing is recommended as an index of susceptibility to both frost heave and thaw weakening. Under the second topic, a soil column and dual gamma system were developed and applied to obtain soil data used in improving and validating a mathematical model of frost heave, the objective of the third research topic.

Findings from a six-year yield and laboratory program of frost action research in four principal areas are summarized. Research on the first topic, frost susceptibility index tests, led to selection of the Corps of Engineers frost design soil classification system as a useful method at the simplest level of testing. At a much more complex level, a new freezing test combined with a CBR test after thawing is recommended as an index of susceptibility to both frost heave and thaw weakening. Under the second topic, a soil column and dual gamma system were developed and applied to obtain soil data used in improving and validating a mathematical model of frost heave, the objective of the third research topic. The model was effectively improved, a probabilistic component was added, and it was successfully tested against field and laboratory measurements of frost heave. A thaw consolidation algorithm was added, which was shown to be useful in predicting the seasonal variation in resilient modulus of granular soils, the objective of the fourth topic. A laboratory testing procedure was developed for assessing the resilient modulus of thawed soil at various stages of the recovery process, as a function of the applied stress and the soil moisture tension, which increases as the soil gradually desaturates during recovery. The procedure was validated by means of appropriate analyses of deflections measured on pavements by a falling-weight deflectometer. Frameworks for implementing findings from the principal research topics are outlined. Keywords: Airfields, Freezing thawing, Frost heave, Frozen soil, Resilient modulus, Roads.

Bearing Capacity of Roads, Railways and Airfields includes the contributions to the 10th International Conference on the Bearing Capacity of Roads, Railways and Airfields (BCRRA 2017, 28-30 June 2017, Athens, Greece). The papers cover aspects related to materials, laboratory testing, design, construction, maintenance and management systems of transport infrastructure, and focus on roads, railways and airfields. Additional aspects that concern new materials and characterization, alternative rehabilitation techniques, technological advances as well as pavement and railway track substructure sustainability are included. The contributions discuss new concepts and innovative solutions, and are concentrated but not limited on the following topics: · Unbound aggregate materials and soil properties · Bound materials characteritics, mechanical properties and testing · Effect of traffic loading · In-situ measurements techniques and monitoring · Structural evaluation · Pavement serviceability condition · Rehabilitation and maintenance issues · Geophysical assessment · Stabilization and reinforcement · Performance modeling · Environmental challenges · Life cycle assessment and sustainability Bearing Capacity of Roads, Railways and Airfields is essential reading for academics and professionals involved or interested in transport infrastructure systems, in particular roads, railways and airfields.