Look up: laitance

1. laitance
   any fluid mixture of fine solids and water,particularly one which contains cement Category: Building industry
   Found on http://www.mijnwoordenboek.nl/definition
   
   
2. Laitance
   A residue of weak and non-durable material consisting of cement, aggregate, fines, or impurities brought to the surface of overwet concrete by the bleeding water
   Found on http://www.moxie-intl.com/glossary.htm
   
   
3. Laitance
   A layer of weak material containing cement and fines from aggregates, brought to the top of overwet concrete, the amount of which is generally increased by overworking and over-manipulating concrete at the surface by improper finishing.
   Found on http://www.pavement.com/glossary/A.html