Dr. Lai is an internationally renowned expert on pavement engineering, construction materials and engineering mechanics. The following are some of his major contributions in these areas:Dr. Lai Invented the Georgia Load Wheel Tester (GLWT) and developed the specification for assessing rutting propensity of asphalt mixtures. The apparatus and the specifications have been used by GDOT since 1989. Since then, this machine and its modified version, called Asphalt Pavement Analyzer (APA), have been used by more than 30 State DOTs in the US and by many highway agencies abroad. As the result of its popularity the Transportation Research Board initiated a NCHRP research program to assess the viability of this apparatus for evaluating rutting propensity of asphalt mixtures and the results were published in the NCHRP Report 508 in 2003.Development of Computerized Pavement Condition Evaluation System (COPACES) for Georgia DOT, which has been implemented by GDOT since 1998, and development of Georgia DOT Pavement Management System (GPAM), which has been implemented by GDOT since 1999.Development of high performance concrete for prestressed bridges for the Georgia Department of Transportation and the Federal Highway Administration, 1996-2000. The compressive strength for the high performance concrete developed was up to 20,000 psi. Several State DOT in the U.S., including Georgia, South Carolina and North Carolina, have since used the concrete for their prestressed bridges construction.Development of micro-milling techniques and the specifications for GDOT for milling existing deteriorated asphalt surface in conjunction with thin asphalt overlaysas part of an asphalt pavement preservation treatment method. Use of this method when compared with the conventional milling and overlay method could result in estimated cost savings of over $55,000 per lane mile. This method has been widely adopted by GDOT since 2008.Developing VESYS-G (probabilistic viscoelastic based) asphalt pavement design system for the FHWA, 1973-1978. This system served as one of the basic frameworks used by the FHWA and TRB for developing the MEPDG Asphalt pavement design method (Mechanistic-Empirical Pavement Design Method).Evaluating and characterizing mechanical properties of many geotextile materials and developing the design method for use of TYPAR (Nonwoven Geotextile produced by DuPont) and other geotextile for unpaved roads and other geotechnical applications when geotextile was emerging as a class of new construction materials in the United States in early 1970s.Developing constitutive equations for non-liner viscoelastic materials and characterizing non-linear creep and stress relaxation properties of different classes of materials including plastics, FRP, high performance aluminum at elevated temperatures and asphalt concrete, 1965-1980.
Highway and Airfield Pavement Design, Construction and Rehabilitation, Concrete Technology, Asphalt Technology, Geotextile, Soil Stabilization, Fiber Reinforced Plastics, Engineering Mechanics, Application of Information Technology for Pavement Systems