Roads and Bridges - Drogi i Mosty
5, 3, 2006, 17-42
5, 3, 2006, 17-42
The counteracting of the concrete scaling problem by means of pre-wetted lightweight aggregate. Part II – Laboratory tests
Abstract
The first part of the paper was published in 2/2006 issue. The salt scaling tests were performed according to the Swedish Standard SS 13 72 44 (so-called Borås method). Freeze/thaw exposure was carried out on the upper horizontal surface of the specimens - cast surface, while the remaining surfaces were isolated against humidity and heat transfer. The scaled material was collected and weighed after a given number of freeze/thaw cycles, and the results expressed as mass per unit area were recorded. The internal frost resistance of the same concretes was tested according to ASTM C 666 A method and according to the Polish Standard PN-B/06250. Additionally, air-content A, specific surface , spacing factor L ̅ and the content of micropores below 0.3 mm A300 in the hardened concrete specimens were measured with the PN-EN 480-11 method on plane sections. It has been found out that the replacement of the fine fraction of the natural aggregate by the adequate fraction of the pre-wetted lightweight aggregate improved the scaling resistance and the internal frost resistance of concrete.