Testing

This report describes a field study concerned with the evaluation of several joint scaling materials. Five liquid seals and seven preformed compression type seals were evaluated on a performance and economic basis. Included in this report is the description of the installation of each joint seal material and the performance of the materials after about three winters of service in a concrete pavement with 39-feet joint spacing. Also presented are the material costs which were made available by the respective manufacturers.

This study was initiated to evaluate Tri-Kote 18 Crect as a concrete treatment. Tri-Kote is a blend of chlorinated rubber, epoxies, and several other materials, which serves as a treatment for both new and old concrete surfaces. According to the manufacturer (T K Products Inc., Minneapolis, Minnesota), Tri-Kote performs as a membrane curing compound and protective treatment against salt scaling for new concrete and as a protective treatment for old concrete. The study of Tri-Kote as a protective treatment for old concrete was assumed not to be essential since the treatment now used (see MHD Specification 3917) is less expensive than Tri-Kote and is considered quite satisfactory from a performance standpoint. The use of Tri-Kote as a membrane curing compound and protective treatment on new concrete was, however, thought to possibly be more economical than the presently used combination of a polyethylene cure and protective treatment, and was therefore subjected to an evaluation study. Since it was found that Tri-Kote, when applied at a rate somewhat greater than that suggested by the manufacturer, did meet Minnesota Highway Department Specification 3754 for concrete membrane curing compounds, only an evaluation of Tri-Kote as a protective treatment on new concrete was made. This study then consists of a comparison of Tri-Kote treated and non-treated concrete with regards to durability.

This report evaluates the use of a "crusher run" limestone base aggregate which has a maximum size particle of two inches. Specific points discussed in the report are cost, gradation, constructability, and performance of this crushed limestone base aggregate.

This study was initiated to evaluate the effect of foamed polystyrene concrete cylinder molds on concrete strength. The objective of the research was to determine if polystyrene molds: 1) significantly protect concrete cylinders against extremes in temperatures during casting and the initial 24 hour cure period, and 2) eliminate the possible effects of rough handling of specimens which is sometimes encountered in stripping and shipping.

This is the appendix for Report 86-07/ Investigation No. 666 "Thickness Design of Low-Volume Bituminous-Surfaced Roads."

Investigation 666 has been conducted to study the design thickness and material requirements for roads in Minnesota with traffic less than 1,000 ADT on the county and city systems. A previous study had been conducted (Investigation 655) to review the methods used by local agencies in Canada and the northern states of the U.S.A. Six of the methods were compared by designing for six specific locations with two levels of traffic each. The designs were from least to most conservative at the different conditions. The Minnesota R-Value and AASHTO Interim Guide procedures were judged to be most appropriate for Minnesota cities and counties. Three traffic counter-classifier devices were evaluated for monitoring of traffic. The Streeter-Amet TrafiComp with a computerized (Model 140 Reader) could be used by the cities and counties for traffic monitoring. A test plan has been devised to document the performance of low-volume roads in Minnesota based on the design parameters used in the Minnesota R-Value and AASHTO procedures. The parameters are pavement materials, embankment soil strength, in-place granular equivalent thickness, and traffic. These four, five, three and three levels respectively have been selected to establish cells for a factorial design study Sixty-five field sections have been established throughout the state. They have been located and documented with the assistance of the respective county engineers. The sections selected have previously been tested with the Road Rater or Benkelman Beam and the traffic analyzed. The thickness has only been checked with the office records. The present field condition has been observed. This information should continue to be obtained to verify the performance relationships used for the AASHTO Interim Guide and the Minnesota R-Value Design Procedure. Additional test sections need to be added to fill out the factorial plan.

A field program of strain and deflection measurements was conducted. The objective of the program was to evaluate the effect of frozen support, tied-concrete shoulder, and tridem-axle loading on concrete pavement performance. Results of the study on the effect of tridem-axle loading are presented in this paper. Field measurements were obtained during October1982 and February 1983 at five pavement project sites located on 1-90 in the State of Minnesota. Measurements included edge and corner deflections and edge strains. Loadings applied were 20 kip single-axle, a 34 kip tandem-axle, a 42 kip tandem-axle, and a 42 kip tridem-axle. Theoretical analysis was also conducted using a finite element program. Study results also indicate that for application to the AASHTO thickness design procedure, a tridem-axle can be considered as equivalent to a single-axle weighing about 50 percent of the tridem-axle and to a tandem-axle weighing about 80 percent of the tridem-axle. Traffic equivalence factors are presented for tridem-axles on concrete pavements.

A field program of strain and deflection measurements was conducted. The objective of the program was to evaluate the effect of frozen support, tied-concrete shoulder, and tridem-axle loading on concrete pavement performance. Results of the study on the effect of frozen support are presented in this paper. Field measurements were obtained during October.1982 and February 1983 at five pavement project, sites located on 1-90 in the State of Minnesota. Measurements included edge and corner deflections and edge strains. Loadings applied were 20 kip single-axle, a 34 kip tandem-axle, a 42 kip tandem-axle, and a 42 kip tridem-axle. Theoretical analysis was also conducted using a finite element program. Study results indicate that pavement deflections and strains are greatly reduced during winter months when the support 1s frozen. Based on analysis of these results, it is concluded that the effect of axle loads applied during the winter can be considered to be only 1/7th as damaging as the same loads applied during fall month

The report discusses the effect of heavy versus lighter axle loads on pavements. It shows how the effect of heaviest loads in terms of fatigue or long term breaking up will cause roads to need maintenance faster. The results of the AASHTO Road Test are used to show that the ratio of damage effect of 10-ton loads is a 307, decrease in road life. The beneficial effect of using tandem and tridem axles is illustrated.

This study was conducted to evaluate the Model 2000 Road Rater as a non-destructive testing device on flexible pavements, rigid pavements, composite pavements and subgrade soils. Emphasis was on the temperature and seasonal response, deflection basin shape, and measurement of resilient modulus of flexible pavements; by the Road Rater. The findings resulted in the Road Rater being utilized as a practical NDT device for the Minnesota DOT.