What are the common mistakes, which affect the quality of concrete?
The ways in which concrete maybe spoilt are many, most common of them being: a. Use of too much or too little water for mixing, or water carelessly added during mixing. b. Incomplete mixing of aggregate with cement c. Improper grading of aggregates resulting in segregation or bleeding of concrete. d. Inadequate compaction of concrete e. Using concrete which has already begun to set. f. Placing of concrete on a dry foundation without properly wetting it with water. g. Use of dirty aggregate or water containing earthy matter, clay or lime. h. Too much troweling of the concrete surface. Leaving the finished concrete surface exposed to sun and wind during the first ten days after placing without protecting it and keeping it damp by proper methods of curing.