Title:
Scaling Resistance of Concrete Paving Block Surfaces Exposed to Deicing Chemicals
Author(s):
Nader Ghafoori and Richard P. Mathis
Publication:
Materials Journal
Volume:
94
Issue:
1
Appears on pages(s):
32-38
Keywords:
aggregates; bulk density; concrete blocks; deicers; durability; freeze-thaw durability; permeability; scaling;
DOI:
10.14359/282
Date:
1/1/1997
Abstract:
This investigation reports on the relative performance of concrete block pavers subjected to repeated cycles of freezing and thawing with deicing chemicals. Six different mix proportions, prepared at their optimum moisture content and fabricated at a commercial plant, were utilized to assess the surface scaling resistance of concrete pavers using the specifications of the ASTM C 672 deicer salt scaling test. Laboratory results indicate that ASTM C 672 can be successfully employed when a minimum cement content of approximately 600 lb/yd3 (aggregate-cement ratio [A/C] of 5:1) is used in the fabrication of block pavers. Test samples having a cement content below this threshold experienced infiltration of the salt solution and consequently failed by surface heaving within the first 25 freezing and thawing cycles. The remaining specimens (A/C of 5:1 and below) endured 50 cycles of freezing and thawing with virtually no signs of surface scaling. When the experimental program extended to 200 cycles, the pavers with cement content of 664 lb/yd3 and higher (A/C of 4.5:1 and lower) displayed minimal scaling and remained crack-free throughout the testing.