Mixts. for mfg. hydrothermally hardened dense silicate concrete - such as very large sand-lime panels in which binder consists of milled sand and active lime

The concrete is used for large, reinforced building elements of grade B200-B500. The mixts. consists of (a) a binder made of milled silica sand and CaO; (b) coarse silica sand used as aggregate; and (c) water. The binder consists of silica sand with Blaine fineness 3000-10,000 cm2/g forming 3-11.5wt.% of the mixt., plus 4-7.8% active CaO, which is pref. slaked by 60-90%. The aggregate has a grain size modulus of 3.1-4.2. The water contains a surfactant, esp. a water soluble carboxylic acid mixt. with chain length C4-C6. The vibration parameters expressed as frequency and acceleration are on or above the limiting curve for covering the reinforcement. The mixt. is hardened in an autoclave. Used in the mfr. of sand-lime mouldings, e.g. panels 6 x 3 x 0.2 meters in size, where the formation of cracks is eliminated, but the reinforcement is completely covered.