Hryhorenko O. Composite water resistant materials based on raw clay without kilns resistant

The work is devoted to develop waterproof building materials based on raw clay without kilns. Proposed a complex inorganic modifier, inclusive: аlkaline granulated slag activated with an aqueous NaOH solution, silica fume and hydrated lime. Proposed to introduce aluminum-containing additive in the form of anion Al(OH)4-, which promotes the formation of stable alkali hydroaluminosilicates. It is found that the amphoteric properties of aluminum and its compounds in the clay dispersion systems at elevated values of pH, by addition of sodium hydroxide makes it possible to obtain sodium aluminate hydrated Na[Al(OH)4], which when dissolved in water forms the active anion Al(OH)4- contributing to the synthesis of water-resistant calcium hydroaluminates: 2CaO·Al2O3·8H2O and 4СаО·Al2O3·19H2O, which was confirmed as a result of X-ray and thermographic investigations. It is developed a water resistant composition (in% by weight): clay - 47.8, аlkaline slag - 33.5, lime - 12, silica fume - 6.7, wherein as the result it is achieved: compressive strength of = 10.7 MPa, a tensile strength at bending = 8.4 MPa softening coefficient Kp = 0.83, water absorption Wm = 8 % and F = 50 frost cycles.