Research into structure formation and properties of the fiber­reinforced aerated concrete obtained by the non­autoclaved hardening

• Main Authors: Oksana Poznyak, Myroslav Sanytsky, Igor Zavadsky, Serhii Braichenko, Andriy Melnyk
• Format: Article
• Language: English
• Published: PC Technology Center 2018-06-01
• Series: Eastern-European Journal of Enterprise Technologies
• Subjects: non-autoclaved aerated concrete; kinetics of swelling; density; strength; polypropylene fiber
• Online Access: http://journals.uran.ua/eejet/article/view/133594
• ISSN: 1729-3774; 1729-4061

We have investigated the influence of the ratio cement:fly-ash and the temperature of mixing water on the properties of aerated concrete mixes and aerated concrete. It was established that the rational cement-fly ash ratio is 1:1; the mixing water temperature is 40 °C. Experimental research confirmed that the introduction of waste from salt processing and metakaolin to the formulation of binding compositions leads to the formation, rather than the metastable hexagonal calcium hydro-aluminates, of the stable compounds in the structure of partitions between pores of the hydrocalumite and hydrocarboaluminate type. That allowed the targeted structure formation of partitions between pores of the non-autoclaved aerated concrete, which improves the density of partitions and the strength of aerated concrete. It is shown that the introduction of polypropylene fibers to composition of aerated concrete does not affect the kinetics of swelling of the aerated concrete array. However, the introduction of polypropylene fibers improves the strength of aerated concrete based on the modified binding composition containing metakaolin by 47 %, the modified binding composition containing carbonate-containing waste ‒ by 32 %. For the aerated concrete of the В1.5–В2 class of strength, at a density within 615‒625 kg/m3, the estimated coefficient of thermal conductivity is 0.16 W/(m∙K), which makes it possible to reduce heat losses through external enclosures. Thus, there is reason to assert the possibility of the targeted control over the processes of forming a strong structure of partitions between pores using the modified binding compositions containing supplementary cementitious materials. The application of polypropylene fibers enables the reinforcement of aerated -concrete array, forming a strong structural frame of partitions between pores, and ensuring greater strength of the non-autoclaved aerated concrete.