Influence of segregation on the permeability of self-consolidating concrete

Segregation resistance of Self-Consolidating Concrete (SCC), concerning the cause of Water-Reducing Admixture (WRA) over dosage and vibration, was characterized by bulk density and image analysis first. Then, the influence of segregation on the permeability of SCC was investigated by the Total Charge Passed (TCP) obtained by integrating current-time curve. Meanwhile, porosity obtained under 50 degrees C and 105 degrees C was measured, and the relationship between TCP and porosity was discussed. Research results show that both the over dosage of WRA and vibration will lower the segregation resistance of SCC, and the effect of the later is more significant than that of the former; both bulk density distribution analysis and image analysis can be an effective way for evaluating the segregation resistance of SCC. Segregation will decrease the permeability of SCC, and there is power function relationship between bulk density and TCP, showing the significant influence of segregation on the permeability of SCC. Enhance the sand to paste volume ratio (STPVR) in the mix proportion of SCC benefits the segregation resistance of SCC on the effect of WRA over dosage, however, the increase of STPVR increases the permeability of SCC. Relationship between TCP and porosity showed that the porosity obtained under 50 degrees C (capillary porosity) is more appropriate than the porosity obtained under 105 degrees C (permeable porosity) for evaluating the permeability of SCC. (C) 2020 Elsevier Ltd. All rights reserved.

Automated summary

The study found that both WRA overdosage and vibration can decrease the segregation resistance of SCC, with vibration having a more significant impact. Bulk density distribution analysis and image analysis are effective ways to evaluate the segregation resistance of SCC. Segregation will decrease the permeability of SCC, while increasing the sand to paste volume ratio (STPVR) can improve the segregation resistance against WRA overdosage.