Iowa Pore Index Test, MLR-80-2, 1980

(1980) Iowa Pore Index Test, MLR-80-2, 1980. Transportation, Department of


File Size:1MB


The objective of the investigation was the development of a test that would readily identify the potential of an aggregate to cause D-cracking because of its susceptivity to critical saturation. A Press-Ur-Meter was modified by replacing the air chamber with a one-inch diameter plastic tube calibrated in milli-. It was concluded that the pore index was sufficiently reliable to determine the D-cracking potential of limestone aggregates in all but a few cases where marginal results were obtained. Consistently poor or good results were always in agreement with established service records or concrete durability testing. In those instances where marginal results are obtained, the results of concrete durability testing should be considered when making the final determination of the D-cracking susceptibility of the aggregate in question. The following applications for the pore index test have been recommended for consideration: concrete durability testing be discontinued in the evaluation process of new aggregate sources with pore index results between 0-20 (Class 2 durability) and over 35 (Class 1) durability; composite aggregates with intermediate pore index results of 20-35 be tested on each stone type to facilitate the possible removal of low durability stone from the production process; and additional investigation should be made to evaluate the possibility of using the test to monitor and upgrade the acceptance of aggregate from sources associated with D-cracking.

Item Type: Departmental Report
Keywords: Aggregates, Concrete, Cracking, Durability, Evaluation, Indexes (Information management), Monitoring, Percent saturation, Porosity
Subjects: Transportation
Transportation > Roads and highways
Transportation > Research
ID Code: 16100
Deposited By: Iowa DOT Library
Deposited On: 18 Feb 2014 17:11
Last Modified: 22 Sep 2014 11:45