Abstract In order to mitigate the environmental impacts in terms of high energy consumption,CO2 emissions and no-renewable resources consumption associated with Portland cement(PC) soft soil stabilization,the stabilization effect of alkali-activated ground granulated blast-furnace slag(GGBS) for Lianyugang soft soil was investigated through laboratory test and then it was compared with that of PC. The results show that the Na2CO3-activated GGBS had the minimum stabilization efficacy for this soft soil. NaOH-activated GGBS stabilized soil had the highest unconfined compressive strength(UCS) at 7,28 and 90 days,however its UCS decreased after 90 days. The GGBS-carbide slag stabilized soil had lower 7-day and 28-day UCS than that of PC mix,whilst the former had much higher 90-day and 180-day UCS than the latter. The Na2CO3,NaOH and Na2SO4 could accelerate the strength development rate of GGBS-carbide slag stabilized soil. The Na2CO3-activated GGBS-carbide slag stabilized soil had only slightly higher 7-day,28-day,90-day UCS and lower 180-day UCS than those without Na2CO3. NaOH significantly increased the UCS of GGBS-carbide slag stabilized soil at 7,28 and 90 days. However the UCS decrease was observed from 90 days to 180 days. The Na2SO4 had the highest activating efficacy for GGBS-carbide slag stabilized soil,and thus was suggested to use in practice due to both the economical and environmental benefits.
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Received: 02 May 2013
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