PERFORMANCE EVALUATION OF GEOPOLYMER CONCRETE THROUGH ALKALI-SILICA REACTION
The potential reactivity of sandstone/siliceous aggregates in geopolymer concrete based on fly ash/GGBS composite mixes was assessed in terms of alkali-silica reaction.The mortar bars made as per ASTM C1260 were exposed to 1M NaOH at 80 ℃ upto 90 days.The exposed samples were examined for their expansion and petrography.It was observed that the samples expanded less than the threshold of 0.1% at the end of 16 days exposure while its OPC counterpart failed by exceeding the limit.At 90 days,the geopolymer mortars containing composite mixes had expansion in the range of 0.31-0.56% as compared to 0.12% for fly ash based geopolymers.Evidences of crystalline zeolites,sodium calcium silicate gel and cracks observed in FESEM after 90 days could be responsible for higher expansion.Reduction in alkalinity of solution/dissolved silica from aggregate after 24 hrs exposure in 1 M NaOH solution indicated innocuous nature of aggregates contrary to the expansion results.It was noted that geopolymer concrete made with high GGBS content exhibited prominent ASR product.It was concluded that siliceous aggregates had less ASR than the sandstone aggregate.
Geopolymer concrete Expansion ASR Microstructure Aggregate
B.Singh Ishwarya.G M.Gupta S.K.Bhattacharyya
Chief Scientist,CSIR-Central Building Research Institute,Roorkee (India) Research Scholar,CSIR-Central Building Research Institute,Roorkee (India) Senior Principal Scientist,CSIR-Central Building Research Institute,Roorkee (India) Director,CSIR-Central Building Research Institute,Roorkee (India)
国际会议
长沙
英文
309-319
2014-06-01（万方平台首次上网日期，不代表论文的发表时间）