The developer/owner shall, when requested b the Village and at his expense, have a commercial testing laboratory prepare and test samples of delivered concrete. One (1) set of tests shall be taken for the first twenty-five (25) cubic yards, or fraction thereof, and one (1) set of tests shall be taken for each additional fifty (50) cubic yards. A set of tests shall consist of four (4) standard cylinders (two (2) shall be broken at seven (7) days and two (2) shall be broken at twenty-eight (28) days), one (1) slump test and one (1) air content test. The laboratory shall perform tests in accordance with recognized ASTM standards and shall submit written reports of such tests to the Village Engineer for review.