Magazine of Civil Engineering (Feb 2021)
Silica concrete compressive behavior under alternating magnetic field
Abstract
Due to the importance of inventing new techniques capable of enhancing concrete structural properties while reducing environmental issues associated with CO2 emissions in concrete industry, which preoccupies environmental scientists, a novel investigation was performed on feasibility of benefitting from Alternating Magnetic Field (AMF) and silica particles to attain this goal. Hence, some experiments were conducted on cylindrical concrete specimens comprising different silica sand contents of up to 10 %, wherein the influence of exposing fresh and hardened concrete to AMF of frequency 50 Hz and density 0.5 Tesla (T) on compressive strength of 7 and 28-day specimens was evaluated. For this, a specialized test setup was assembled such that the specimen could be subjected to compressive force and AMF, simultaneously. It was found that AMF can improve concrete compressive strength, where this technique is more efficient as to exposing hardened concrete. What was significant about the results was the fact that adding silica sand not only improved concrete mechanical strength but also considerably enhanced the effectiveness of AMF in increasing concrete compressive strength, when applied to hardened concrete. For instance, replacing 10 % of cement content with silica sand increased compressive strength of 28-day specimens by 8.4, but adding 10 % silica sand along with exposing specimens to AMF yielded an increase of nearly 21 % in real-time. Thus, developing this method can result in a new generation of smart constructions. Moreover, by adding 10 % silica sand, the emission of carbon dioxide, a greenhouse gas, reduces by 10 percent while significantly enhancing compressive strength.
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