Edmundas Spudulis

Study of the Effect of Replacing Microsilica in Heat-Resistant Concrete with Additive based on Metakaolin

A comparative study is provided for the effect of microsilica additive and one based on metakaolin on hydration of alumina cement and cement stone structure formation after hardening and firing. It is established that in a composite with alumina cement an additive based on metakaolin promotes transfer of cement minerals into solution more rapidly than microsilica additive, and also that composite hydration with additive based on metakaolin proceeds more rapidly than a composite with microsilica. Additive based on metakaolin compared with microsilica improves mechanical properties of heat-resistant concrete based on a chamotte filler: after hardening and firing the ultimate strength in compression for specimens with additive based on metakaolin is higher by 5 – 27% than this index for specimens with microsilica additive.

Investigation of Hydration Features of the Special Concrete with Aggregates of Various Metal Particles

This study presents an analysis of various size metal particle waste (MP) influences on Portland cement (PC) paste hydration course, concrete sample structure densification during hardening and physical-mechanical properties. Investigations have shown that MP filler accelerates maximum heat release rate in PC pastes. MP intensifies structure development in the early phase, but slows it down in later PC hydration period. After 28-days of hardening the compressive strength of the concrete samples without MP filler is about 20% higher than of samples with MP. When in concrete composition microsilica and MP fillers are used together, compressive strength of concrete sample composition is up to 50% higher than of samples with MP filler only.

Effect of Carbon Fiber on Medium-Cement Heat-Resistant Concrete Properties1

Heat-resistant medium-cement concrete with calcium aluminate filler is studied. It is established that addition of carbon fiber facilitates an increase in concrete strength in compression and thermal stability. Explosive breakage only does not occur for specimens with polypropylene fiber on heating a concrete specimen at a rate of 40°C/min to 1000°C.