DOI

10.5703/1288284315185

Abstract

The primary objective of the present study was to identify the critical properties (based on the laboratory tests) that could be correlated to the field performance of the rapid setting repair materials.

The first phase of the project involved laboratory evaluation of six commercial rapid-setting repair materials (RMs). When tested in the laboratory, all but two exhibited acceptable rates of strength gain and three RMs displayed relatively poor freeze-thaw resistance. All the RMs exhibited acceptable values for free-shrinkage, high resistance to cracking and good bond to substrate concrete. The resistance to chloride ion penetration of one of the RMs was very poor.

The second phase of the project involved field installation and performance evaluation of the RMs. It was seen that while, in most cases, the controlled laboratory conditions yielded consistent mixes and acceptable performance, the properties of mixes produced on site were more variable. This variability was the result of somewhat uncontrolled changes in the amount of aggregate extension used, moisture content of the aggregates, amount water added and ambient temperature conditions. Follow-up inspection of the repair patches indicated that all the patches except one underwent premature failures (primarily cracking and edge de-bonding). The ambient temperature during the repairs was around 10°C and this led to an extended set-time for all the materials. The 12-hr compressive strengths values of the specimens from the field-mixes were in some cases lower than the 4-hr compressive strength values of laboratory mixes. Since the repairs were open to traffic after approximately 4 hours after placement, the low early age strengths could be a potential reason for premature failures of some of the patches.

In general, several materials were found to be very sensitive to excess water added during mixing resulted in a significant impact on the durability properties – especially the freeze-thaw resistance. In the field, for most of the materials, the consistency of the mixes varied from batch to batch – this can be attributed to the variations in the aggregate extension adopted, mix-water added and also the moisture content of the aggregates used. Construction related issues (consolidation and finishing) also played an important role in the performance of the repair patches.

Based upon laboratory and field results, modifications to the current INDOT performance specifications for rapid-setting repair materials have been suggested. Some recommendations for improvements in quality control measures of field-mixes and construction related issues have been suggested. Future research directions involving the evaluation of the robustness of the repair materials with respect to the uncertainties present on site have also been highlighted.

Report Number

FHWA/IN/JTRP-2013/02

Keywords

rapid-setting repair materials, field performance, mechanical properties, durability, shrinkage, SPR-3019

SPR Number

3019

Performing Organization

Joint Transportation Research Program

Publisher Place

West Lafayette, Indiana

Date of this Version

6-2013

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