Use of polymer grids for short- and long-term crack control in concrete slabs

摘要

Shrinkage cracks in Portland cement concrete can cause serious problems when cracked reinforced concrete is subjected to corrosive agents such as salts. The seepage of salty solutions through the cracks into the reinforcing steel can lead to corrosion of the steel and ultimately failure of the structure. This paper presents the results of an extensive experimental investigation designed to evaluate the potential of using polymer grids to minimize shrinkage cracks and their subsequent effects on corrosion of steel reinforcement. The investigation consisted of a short-term and a long-term programme. In the short-term programme, 120 x 600 x 2000 mm concrete slabs were subjected to drying shrinkage. In the long-term programme, 100 x 500 x 3200 mm concrete slabs were loaded and unloaded under severe conditions of deicing salt applications. The test results showed that the use of polymer grids can minimize shrinkage cracking. Also, in the occurrence of a crack, the presence of polymer grids as secondary reinforcement resulted in controlling the crack width.