Properties of fire-retardant vermiculite-concrete composite and fine-grained concrete for two-layer reinforced cement structures

Objective. Development of compositions of fire-retardant vermiculite-concrete composites for reinforced cement structures. Investigation of the properties of fire-retardant vermiculite-concrete composite and fine-grained concrete for two-layer reinforced cement structures.

Method. Methods for increasing the fire resistance of reinforced concrete structures are considered. Research is focused on the development of fire-retardant composites using expanded vermiculite and volcanic ash. To improve the physical and mechanical properties of the fire-retardant composite, a mixture of Portland cement, gypsum, lime, basalt fiber, saponified wood resin, volcanic ash and expanded vermiculite has been developed. For the study of vermiculite concretes reinforced with basalt fiber, a second-order rotatable plan of the regular hexagon type was used.

Result. Fiber-vermiculite concretes are proposed, which have improved fire-retardant properties compared to known compositions. This is due to the better preservation of the fiber-vermiculite-concrete layer when heated as a result of fiber reinforcement. Also, thanks to the addition of SDO, the fire-retardant properties of the composite increase due to the additional porosity of the fiber-vermiculite-concrete. The parameters of the "stress-strain" diagram of a vermiculite-concrete composite and fine-grained concrete have been obtained.

Conclusion. Vermiculite concretes with an average density of 480-560 kg/m3 have the best fire-retardant properties. The developed two-layer reinforced cement structures have high fire resistance. 

1. Milovanov A.F. Fire resistance of reinforced concrete structures. Moscow: Stroyizdat. 1986. 225 p. (In Russ).

2. Ilyin N.A. Consequences of fire impact on reinforced concrete structures. Moscow: Stroyizdat. 1979:128. (In Russ).

3. Milovanov A.F. Fire safety of reinforced concrete structures after a fire. M.: 2005: 122. (In Russ).

4. Khezev T.A. Technology of reinforced cement structures of high fire resistance with a heat-shielding layer of efficient lightweight concrete: diss. … Dr. tech. Sciences. Rostov-on-Don. 2007: 304. (In Russ).

5. Lysenko E.F. Armored structures. Kyiv: Vishcha school. 1981: 191.

6. Mitrofanov E.N. Armocement. L.: 1973: 208. (In Russ).

7. Panarin S.N., Khezhev T.A., Somov V.I. Fire resistance of reinforced cement with a fire-retardant layer based on expanded vermiculite. F. E. Dzerzhinsky. M.: 1982; 98–101. (In Russ).

8. Yakovlev A.I. Calculation of fire resistance of building structures. Moscow: Stroyizdat. 1888: 142. (In Russ).

9. Nekrasov K.D. Recommendations for the protection of concrete and reinforced concrete structures from brittle fracture in a fire. Moscow: Stroyizdat. 1981: 21. (In Russ).

10. Strakhov V.L., Krutov A.M., Davydkin A.M. Fire protection of building structures. M.: TIMR. 2000: 433 (In Russ).\

11. Akhtyamov R.Ya. "Vermivol" - a new fire-retardant coating based on expanded vermiculite. Construction materials. 2002; 6: 6–7. (In Russ).

12. Panarin S.N. Reinforced cement structures of increased fire resistance: a visual aid. L.: LDNTP. 1982:23 (In Russ).

13. Dubenetsky K.N., Pozhnin A.P. Vermiculite. L.: Stroyizdat. 1971: 175. (In Russ).

14. Gedeonov P.P., Spirina V.S. Cement-vermiculite plaster mortars for residential and public buildings. Building materials based on vermiculite, slags and ashes: coll. Proceedings of UralNIIStromproekt. Chelyabinsk. 1975: 24 - 30. (In Russ).

15. Guidelines for the implementation of fire-retardant and heat-insulating plasters in a mechanized way. Moscow: Stroyizdat. 1977: 46. (In Russ).

16. Guidelines for the composition and use of heat-insulating and fire-resistant perlite plasters. Moscow: Stroyizdat. 1975:. 15. (In Russ).

17. Tikhonov Yu.M. Aerated lightweight and heat-fire-retardant concretes and mortars using expanded vermiculite and perlite and products based on them: author. diss. … Dr. tech. Sciences. St. Petersburg: St. Petersburg State University. architect.-builds. un-t. 2005. 40 p. (In Russ).

18. Dubenetsky K.N., Tikhonov Yu.M. New insulating material Fire business. 1967; 6: 30–31. (In Russ).

19. Khashukaev M.N. Technology and properties of cellular fiber-reinforced concrete based on volcanic rocks: diss. Ph.D. St. Petersburg: St. Petersburg State University. architect.-builds. un-t. 2002. 127 p. (In Russ).

20. Rabinovich F.N. Composites based on dispersed reinforced concrete. Questions of theory and design, technology, construction: monograph / 3rd ed., revised. and additional M.: ASV. 2004; 560. (In Russ).

21. Nalimov V.V., Chernova N.A. Statistical methods for planning extreme experiments. M.: Science. 1965: 340 (In Russ).

22. Kryzhanovsky I.I., Sviderskaya O.I. Experiment planning technique for solving a typical problem on the choice of chemical additives to concrete. Mathematical methods in research of concrete technology: tr. All-Union. scientific research in-ta water supply, sewerage, hydraulic engineering. facilities and engineer. hydrogeology. Issue. 5. Kharkov. 1971: 102–114.