Eco-friendly UHPC prepared from high volume wet-grinded ultrafine GGBS slurry

The development of ultra-high performance (UHPC) concrete was restricted due to the large consumption and high cost of cement. In this study, eco-friendly UHPC was prepared by ultra-high content of wet-grinded ultrafine ground granulated blast furnace slag (UGGBS). And the content of mineral admixture in the cementitious system is up to 50%, of which UGGBS is as high as 40%. It was proved that the mechanical development, microstructure and hydration process of UHPC were significantly improved by UGGBS. The results showed that the compressive strength of G0UG20 was increased by 27% and 15% at 3 and 28 days compared with the reference group. Even if the cement content was reduced, the compressive strength of high volume UGGBS blended UHPC was still higher than the reference group. The addition of UGGBS significantly refined the pore structure and densified the hardened system. Meanwhile, the MCL and Al/Si of C-S-H gels were improved by UGGBS. In terms of environmental and economic benefits, the CO2 emissions and production costs were reduced by the addition of UGGBS.