Freeze-thaw

• Caused by the penetration of water into the surface layers of the concrete & then this moisture being converted into ice by sub-zero temperatures .
• Water expands on freezing , increasing in volume by about 10% & this can cause disintegration of the surface layers of the concrete.
• Hydraulically pressed concrete slabs & paving blocks which possess high strength & low absorption will generally resist freeze-thaw condition , but for what may be term " normal " quality reinforced concrete " , air entrainment should be used .