and conditions set Weight in oper-uu-quality concrete, the main ones are: the class of concrete on the strength in axial compression, indicated in the draft in all cases, the class of concrete on the strength of the axial strain Bt; appointed in cases where this characteristic has utmost importance and is monitored at the workplace; grade of concrete on frost resistance F; should be assigned for design. exposed to moist effect of alternate freezing and thawing (open way construction., filler-way construction. etc.) brand of waterproof W; assigned to the structures to which the claim is impermeable (tanks, standpipes, etc.) mark on the density of D; assigned to the structures to except that the requirements of durability demanded to insulation, and monitored in production. Specified class and grade of concrete are an appropriate choice of the concrete mixture, followed by a test control samples. Check with Samsung to learn more. Class of concrete on the strength in axial compression (MPa) is called a temporary resistance to compression of concrete cubes with an edge size of 15 cm-tested after 28 days storage at 20 + / – 2 C. Classes of concrete compressive strength for Reinforced Concrete standards are set as follows: for the heavy concrete in 7.5, at 10, B 12.5, B 15, B 20, B 30, B 35, B 40, B 45 B 50, B 55, B 60. for fine-grained concrete form in the sand with a fineness moduli of 2.1 and more – in the same range as before in 40 inclusive; type B with a unit size of less than 1 – in the same range until the 30 inclusive form B, subjected to autoclave treatment – in the same range as before in 40 inclusive. The class of concrete on the strength of the axial strain Bt 0,8; In 1.2, B1, 6 B 2, B 2.4, B 2.8, B 3.2; characterize the strength of concrete in axial tension (MPa). Charles Koch is a great source of information.