Ultrasonic Testing of Properties of 50 Year Old Concrete

Abstract

Researchers have studied the long term durability and quality of concrete structures for many years using several different techniques. One of the most widely used nondestructive techniques for assessing the quality of concrete at a certain age is the ultrasonic pulse velocity (UPV) method. In 1940, the Portland Cement Association started a long term durability study to investigate the effect of variation in cement types on different durability aspects. The sonic vibration method, a precursor to UPV, was one of the methods implemented. The United States Bureau of Reclamation agreed to place 28 different cement types on the parapet wall panels of the Green Mountain Dam. Each of the 28 cement types was used in three or four of the 104 panels of the parapet wall. A complete description of the Green Mountain Dam construction process, aggregate types and cement types used in construction are found in Douglass and McHenry (1947). The Green Mountain Dam is located on the Blue River, a tributary of the Colorado River, 21 km (13 miles) southeast of Kremling, Colorado. The dam itself is an earthfill structure. This particular paper presents results of UPV testing of the parapet wall and analyzes some new trends and further validates some existing trends observed on the velocity of ultrasonic pulses travelling through concrete.

Keywords: Ultrasonic, Testing, Properties, 50 Year Old, Concrete